In individual, and not only in individual construction, when the scope of work reaches large volumes, some of the work and technological elements provided for in the project can be postponed to a later date, focusing on the main direction. One of these options is the installation of a roofing system. And here the point is not only to save on materials, postponing the attic equipment for later, simply erecting walls, interfloor ceilings and laying the main communications without a reliable roof. And if for the speedy settlement it is necessary to carry out a lot of finishing work inside the room, then it is possible to wait a little with the insulation equipment in the attic.

What does cold roof mean?

Modern roofing materials, despite such a variety of forms, materials, technologies and prices, are in many respects similar to each other in one thing - they can be used both for installing a cold roof of a building, and when building a roof with a layer of insulation. In fact, these are materials of universal use, but when working with them, you need to know and take into account the specifics of their application.

For the roof, equipped for attic rooms, a layer of insulation is used to prevent heat loss in winter and maintain a comfortable temperature in the room in summer. For such options, both traditional insulation technologies using mineral wool, polystyrene, sprayed types of insulating foam as a heater, and new types of new natural-based heaters that are just coming into fashion are used. The roof of such a building makes it possible to obtain additional space in the building, which can be used as a workshop, library or billiard room.

A cold roof, in contrast to a design with insulation, has a simpler device. This is a standard roof structure, the main purpose of which is to protect the building from precipitation. At the same time, a cold roof device can also be made as an intermediate solution, in which it is planned to install a roofing pie from insulation and all related layers of hydro- and vapor barrier in the future.

A cold roof can be made from almost the entire range of roofing materials; for its construction, the following can be used:

• Slate;
• Profiled metal sheet;
• metal tile;
• roofing iron;
• Roll roofing materials;
• Ondulin;
• Bituminous materials;
• Tiling.

At the same time, for the installation of a cold roof, metal tiles and profiled metal sheets are the favorites today.

Cold rolled metal roof

In order to quickly erect the roof of a building with the least losses, the most rational today is the use of sheet metal products as a coating material. Metal profiled sheets or metal tiles, compared to other types of roofing materials, have several advantages:

• Coatings made of metal tiles or profiled sheets are highly reliable and durable, the service life of such coatings is at least 50 years, however, subject to all the rules of roof construction technology;
• Metal tiles and corrugated sheets are truly universal materials for their intended purpose - they are easily used both to cover large areas and small-sized roofs.
• The material, unlike tiles or slate, has a lower weight, which means that lighter structures can also be used for the roof structure;
• The strength of the material, as practice shows, without a doubt, it perfectly withstands heavy loads, copes with its functions on various roof slopes from 14 to 65 degrees;
• The convenience of roofing from these types of materials is indisputable, in addition to the large size and ease of installation of the roof, the metal profile itself and the metal tile contain many additional accessories that allow you to mount all the elements of the roof without much difficulty.

But this is only one side of the coin, or in this case, the roof, under it there are quite a few features that are part of the concept of a cold roof. For an unheated attic space formed by a rafter system and roofing, the presence of a certain set of elements that together form the concept of a cold roof is characteristic.

Metal as a roof covering, in addition to all the above positive qualities, also has negative ones, which very seriously affect both the condition of the roof itself and the condition of the metal. Firstly, the diurnal temperature difference in the spring-summer period makes it possible for a drop of condensate to appear on the inner surface. Secondly, a metal roof requires the installation of special additional elements for laying communications through the coating. Thirdly, the roofing material itself is still very noisy, during rain or hail, those under the roof will clearly hear how literally every drop of rain or a grain of hail falls.

Based on this, the installation of a cold roof using metal materials requires the use of special additional materials and laying technologies recommended by the manufacturer.

The specificity of equipping a building with this type of roof lies in the use of materials that make it possible to completely or partially rid the internal space of the formation of condensate, and in case of its occurrence, remove it from the attic space as quickly as possible.

The basis of such a roof, however, like any other roof of this type, is a truss structure, the standard set of which is rigid rafters located in strict accordance with the project, interconnected into a rigid structure. The dimensions of the rafters themselves, the shape and methods of docking with each other in this case do not play a special role, it is important that the slope of the rafter legs provides the most optimal slope angle from 14-65 degrees.

A layer of waterproofing material is laid on top of the rafters. The essence of this layer is the ability to prevent moisture from entering the attic space from leaks in the roof. Modern nonwoven materials make it possible to solve the problem of moisture from condensate in a complex way; today, a vapor-permeable membrane is used as such a material, capable of passing steam in one direction and not letting moisture and steam back. Such a layer of waterproofing is laid on the rafters and fixed with building brackets.

On top of the membrane along the rafters, counter-battens are fastened. Planks not only fix the membrane itself, but also form, thus, an additional volume between the membrane and the coating. Further, as in a conventional roofing structure, lathing strips are installed and metal sheets of the coating are already on top.

Such a schematic representation allows the main elements of a cold roof, however, to complete the picture, it is necessary to dwell in more detail on some of the nuances of the design.
The vapor-permeable membrane waterproofing, installed over the rafters, is laid in sheets horizontally from the bottom up, so that the layer located above overlaps the bottom layer by at least 10-12 cm. This arrangement will allow moisture to quickly drain down when it gets under the metal coating. However, when laying the sheet of the waterproofing layer, the material is laid without tension, with a deflection between adjacent rafters of 1.5-2 cm. Such a deflection provides more efficient removal of moisture and at the same time increases the internal space under the metal tile.

Below, on the beams of the rafters, not only drips are installed - solid metal strips along which water flows from the tiles, but also a special perforated strip or mesh with small cells to ensure unhindered passage of air under the roof. Perforation securely closes the space from the penetration of birds, bats, animals and large insects into the attic and at the same time provides air flow under the metal surface.

Constant air circulation is ensured by the presence of additional holes in the upper part of the roof under the ridge strip, allowing the passage of heated air. This roof design allows air to circulate with the greatest efficiency, air passing under the metal coating, gradually heating up, exits through the holes under the ridge bar.

Conditions for laying communications under a cold roof

As well as for the usual roof structure of the house, the space under the roof of metal profiles or metal tiles can be equipped with a chimney, cable or antenna lines, ventilation ducts and viewing windows or glass inserts can be installed in the coating.


For a cold roof, the placement of these communications has some features. For chimneys passing through the attic space, especially those that use metal structures as pipes, it is imperative to carry out insulation, since it is these elements that will cause condensation on the profile. For cable lines passing through the metal coating of a cold roof, it is necessary to use special antenna outputs that fit snugly against the surface of the metal tile.

A cold roof, in addition, requires that, in addition to the main ventilation system, auxiliary ventilation ducts be installed to bring air outside. Most often, special ventilation outlets with deflectors are used as such channels, providing air draft.

A little about saving

Considering the option of building a building with a cold roof, as a permanent or intermediate option for roofing, it is necessary to understand some of the nuances associated with the economic aspects of this type of construction. Comparing the design of a cold roof for a two-story single-apartment residential building with the same roof, only with insulation, it is necessary to add another 10-12% of the amount of annual costs to the heating costs of the task. At the same time, simple insulation of the attic surface gives the opposite effect in the form of energy savings of 3-5% of the annual requirement.

Assessing the construction of a cold roof, it will undoubtedly cost less, while the cost of the project can be 35-50% less than the cost of an insulated roof. But in order to carry out work on insulation in the future, the cold roof as an intermediate option is the most optimal, because the space can also be used as an additional storage space for the material. True, the insulation of such a ready-made roofing system will be a more complicated process than building a roofing pie right away.

Currently, in newspapers and on Internet sites that provide information related to construction, there are a large number of offers for the provision of services that provide installation of roofing for country houses and country cottages.

In most cases, they are referring to insulated roofing, which is often referred to as a roofing pie. At the same time, there is almost no mention of a cold roof. And completely in vain, since it is she who represents the optimal solution, especially for some type of buildings. In addition, it is a very affordable option for the general population in terms of its cost.
This article aims to convey information about when it is better to install a cold roof and how to do it.

Usually the decision to install a cold roof is due to material considerations or the lack of a great need for a warm roof. As an example, we can mention the construction of a country house, in which it is not planned to have an attic room. In this case, there is no need to insulate the attic. This option is acceptable for outbuildings, for which it is enough to insulate only the ceiling, leaving the roof cold. Modular houses made up of block-containers can also serve as such an example. The modules themselves are insulated. It is only required to install a cold roof. It is quite clear that this type of roof is quite suitable for country houses, sheds, gazebos, holiday houses and other structures. In rural areas, houses, as a rule, have non-residential attics and, accordingly, cold roofs, which saves significant money.

What is a cold roof?

Structurally cold roof presents no difficulty. To protect the attic space from condensation that occurs on the inner surface of the roof, a membrane with waterproofing properties or a film is fixed on the rafters.
Before installing the roofing, counter crate and crate are stuffed. Under the ridge and on the slopes, exits are installed through which water vapor is removed from the space under the roof. In addition, dormer windows also serve to ventilate the attic space. The absence of difficulties during installation and subsequent operation of a cold roof is due to the simplicity of its design.
In the event that it is planned to insulate the attic or make an attic in the future, it is necessary to use a TYVEK type membrane for waterproofing, since the micro-perforated film, which is usually used when installing cold roofs, does not make it possible to provide the necessary tightness of the insulation.
If the roof is not insulated, then it is quite possible to get by with the use of micro-perforated film, which has a lower cost. Its installation provides for a sag of 20 mm, which ensures that water drains into the middle of the run and protects the rafters from moisture. The waterproofing in the area of ​​the ridge is broken in order to provide an outlet for air.
There is an opinion that in regions where severe winters are observed, it makes no sense to install a cold roof. It should be noted that it is wrong. The history of cold roof and attic equipment goes back hundreds of years. The use of such roofs is possible in any area. It is only necessary to comply with the conditions for warming the attic floor, which are required by the norms of the given area of ​​\u200b\u200bresidence. In regions where there are large readings of negative air temperatures, special attention should be paid to the insulation of process equipment, which will avoid the appearance of condensate, which will inevitably lead to icing.
As a coating for a cold roof, various ones can be used that do not require the installation of a solid base. A suitable option would be to use either a profiled sheet. They are distinguished by reliability, manufacturability and durability. Especially recommended are those that have a polymer coating, which can significantly increase the life of the roof.
An example is Colorcoated steel, which is produced in England by Tata Steel. The warranty period of operation is 20 years, while in reality such a roof will serve at least 50. For those who believe that the profiled sheet does not meet their aesthetic needs, we can recommend the use of metal tiles. outwardly similar to natural and at the same time it is distinguished by its low weight and the absence of difficulties during installation.

Or maybe even easier?

Of course, this is quite possible, especially if you have to install a roof on buildings that will not subsequently need insulation. The use of a profiled steel sheet with an anti-condensation coating will greatly simplify the installation work and reduce the cost.
This material has the structure of synthetic felt, which is applied during the manufacturing process to the underside of the profiled sheet. The interweaving of polyester fibers creates air pockets in large numbers. This structure gives the coating the ability to accumulate and retain a large amount of moisture, the value of which can reach 1 liter per m2. An increase in air temperature leads to intensive evaporation of water.
In this way, it is possible to solve the problem of condensate that appears on the inner surface of the roof and at the same time not to use waterproofing. And although in this case there is a slight increase in the cost of the roofing material, it is compensated by the absence of the need to install a counter-batten, install a waterproofing film, and reduce the time required for installation by almost 2 times. Simultaneously, the facilitation of preventive inspections and maintenance of the roof is achieved.
Installing a roof with an anti-condensate coating is similar to working with conventional corrugated board. It does not require the use of special tools and the presence of certain skills. As a result, the use of this material for roof installation can reach 30% savings on the estimated cost.
The use of an anti-condensation coating can be a godsend for those who install a roof on buildings that do not have an attic floor. For the most part, this applies to buildings with a pitched roof. It can be verandas, garages, sheds, gazebos. They do not require the use of a film to provide waterproofing. To all other advantages of this type of coating, you can add the attenuation of wind, rain and hail noise by an average of 2 dB, easy cleaning from dirt, the absence of fungus and mold.
Opportunities for original solutions
Nowadays, the market for building materials is so diverse that for those who want to give an original look to their roof, practically nothing is impossible. This statement may well be attributed to the cold roof. The supply of a large amount of light to the attic, veranda or gazebo will be ensured by the installation of transparent inserts made of profiled polycarbonate. And canopies, if they are small in size, can be completely transparent at all.
The advantage of a profiled sheet made of polycarbonate, of course, is its ability to transmit light, which lasts for 10 years of operation. To it can be added high resistance to low temperatures and mechanical stress, the ability to reduce the intensity of ultraviolet radiation.
For a cold roof, an interesting solution may be the installation of windows in non-residential premises, the purpose of which is to be used as emergency exits. Installing a number of such windows in the attic will allow it to be used as a dining veranda or solarium. It is very convenient to sit in it during bad weather. By the way, this option will be necessary for those whose plot sizes do not allow installing a gazebo.

cold roof, in which design features and the ability to apply modern solutions and materials find their combination, make it almost an ideal option for the construction of cottages and country houses. In addition, its installation is affordable for any ordinary consumer.

Most modern houses have a cold attic. Compared to a warm attic or attic, such a roof is less expensive in terms of materials and installation time, but don't let the simplicity of the device fool you. To avoid mistakes when constructing a cold roof, use the instructions from RMNT.

Thermal engineering of a cold attic

Warm air always moves upward, penetrating even the slightest cracks and gaps in the ceiling. To keep maximum heat inside the house, a sufficiently powerful heat protection belt up to 300-350 mm thick is arranged above the ceiling. Thermal insulation is laid as tightly as possible in order to slow down the ascending hot flow as much as possible.

The insulation needs to be protected from getting wet, so the steam that is carried by warm air needs to be blocked. For these purposes, the ceiling is covered from the inside with a vapor barrier - a special membrane that allows gases to pass through, but retains evaporated moisture, and rmnt.ru has already talked about these materials in more detail in a separate article. On the inside, the heat insulator has a sufficiently high temperature and therefore condensate does not fall on the vapor barrier membrane.

The outer side of the heater is cold. It is ventilated with outside air, so that moisture does not accumulate in the insulation. The attic floor is the only stage of thermal protection; no other cold attic structures perform this function.

The main problem with a cold roof is that condensation forms on the back of the roof during temperature changes. Since the air in the attic remains warm for a long time after sunset, and the roof almost immediately takes on the temperature of the outdoor environment, the appearance of moisture drops is an inevitable phenomenon. Falling down, they fall on the floor cake, moistening it. This leads to the weighting of the filler, the loss of heat-insulating properties, the formation of dampness and mold. That is why, when installing the roof of a cold attic, it is mandatory to install under-roof waterproofing.

truss system

Since no insulation will be laid between the rafter legs, their pitch and section can be chosen absolutely freely. The kalk.pro service will help in this matter: in the “Roofs” section, it is possible to model and calculate load-bearing elements and sheathing for any type of roofs.

The most suitable lumber for rafter legs is a board 50-70 mm thick and 100-200 mm wide. Based on the weight of the roof and the predicted snow load, the step between the rafters of this section is adjusted in the range of 60-120 cm. It must be taken into account that during installation the rafters are reinforced with a counter-lattice 30-40 mm thick, so it is reasonable to initially choose a slightly smaller width of the board.

When installing the rafter system, it is imperative to set the legs in common planes in order to subsequently avoid problems with leveling the crate. For these purposes, it is recommended to rigidly fix the extreme rafters on the spacers, pull the cords in the upper and lower parts of the slope, and then put the rest of the legs along them. The rafters must be temporarily fastened from the inside of the roof until the waterproofing and counter battens with the batten are installed on the outside.

Roof waterproofing

Micro-perforated film is best suited for waterproofing a cold roof. This is one of the cheapest and easiest materials to install, which completely solves the problem of condensation. During installation, the roll of film is rolled out across the slope of the slope, starting from the bottom. Each subsequent sheet should be laid with an overlap on the lower one with a width of about 70 mm.

Installation of the hydrobarrier is best done in calm weather. Temporary fastening is carried out with brackets to the upper edge of the rafter legs, while adjusting the stapler spring force so that the bracket does not press close to the film, pushing it through, but forms a gap of about 0.5 mm. The film must be fixed in such a way that a sag of about 20-25 mm is formed between the rafters. This way, water will not soak the counter grille, collecting at the lowest point.

When the entire slope is covered with a hydro-barrier, you need to nail a counter-lattice - slats of the same thickness as the rafter legs. Before nailing the rail, the side with which it is adjacent to the rafters can be coated with any alkyd enamel. Lumber for counter-battens and battens should be pre-treated with fire-bioprotective impregnation. It is recommended to fasten the counter-lattice with either buffed nails or anodized screws. Black hardened screws are not suitable for this purpose.

The counter-lattice performs several functions at once. Firstly, it reliably presses the hydro-barrier, while blocking the punctures at the attachment points. Secondly, due to the increased distance between the coating and the waterproofing, a path for the upward air flow appears, due to which the formed moisture quickly evaporates.

Lathing installation

The type and method of installation of the transverse lathing depends on the roofing used. For a cold roof, both slate and profiled sheet, metal and bituminous tiles are well suited. It all depends on aesthetic preferences and the slope of the slopes.

In total, two types of lathing for a cold roof can be distinguished: solid and plank. A solid crate is well suited for, as well as materials like corrugated board, which make a lot of noise during rain. Tight pressing of the coating to a solid massive base eliminates the unwanted acoustic effect and greatly facilitates the installation of the roof.

A solid crate is made either from OSB of classes 3 and 4, or from moisture-resistant plywood on phenol-formaldehyde resins. The minimum thickness of plywood is 8 mm with a rafter step of 60 cm. OSB has a looser structure, for reliable fixation of fasteners in it, the thickness must be at least 12 mm.

It is recommended to install a continuous crate, starting from the front gable, laying solid sheets and shifting the extensions to the least visible part of the slope. Between the plates it is necessary to leave a deformation gap of the order of 10-15 mm. If the joint between the plates is not in the area of ​​​​the rafter leg, fastening through a backing rail 20-25 mm thick is allowed according to the same principle as fastening horizontal joints.

When all sheets are fixed, the joints must be filled with non-hardening bituminous mastic or special roofing sealant. After sealing, it is recommended to check the plane of the crate using a stretched cord, if necessary, installing linings of different thicknesses in the places of the main fastening.

The device of a plank crate is much simpler. Both edged and unedged boards are suitable for it, it is only important not to use materials that are not calibrated in thickness. Sheathing boards are nailed perpendicular to the rafters. In doing so, two factors must be taken into account:

1. The main boards to which the coating of the selected format is attached should be located on the overlap line between the sheets. For these purposes, it is recommended to select the widest boards.
2. In the range between the main boards, several additional boards should be installed, taking into account the degree of filling of the crate recommended by the manufacturer and the number of intermediate rows of fastening.

If you choose an unedged board, it must be placed with a wider plane up. For fastening it is better not to use screws and self-tapping screws, ordinary nails will work better than any other fastener.

Cold attic ventilation

The last question in the arrangement of a cold roof is the ventilation of the attic. It should be adjustable so that in the summer heat at the level of the attic floor the temperature is close to the air temperature, and in the event of a sharp cold snap there is no heavy condensation. In winter, the ventilation is blocked, which makes it possible to exclude intensive blowing of the insulation and save as much heat as possible.

As a rule, in a private house, an entrance door to the attic and one openable window in the upper part of the gable on the opposite side is enough. If the roof is hip, you need to make a small ledge under the window.

For roofs with an area of ​​more than 300 m 2, additional vents are recommended. They cut into the upper part of the slope and help to remove the air entering the attic in the Mauerlat area. To ensure full air circulation, when sewing spotlights, you need to insert perforated panels after 70-80 cm. It is possible to avoid the installation of vents when covering the roof with a material with a wavy profile. On the line of convergence of the slopes, you need to leave a gap of about 100-140 mm, which is covered with a wide ridge.

Related videos

rmnt.ru, Igor Maksimov

Read in the article

Material characteristics

A metal tile is a roofing covering based on galvanized steel with a polymer or paint layer, used for the construction of a cold or warm roof. It is produced by cold rolling from steel billets. The strengths of metal tiles are:

• A light weight. One square meter of metal tile weighs 5.5-6.5 kg, which allows laying on a sparse crate without reinforcing the roof truss frame.
• Long service life. High-quality metal tiles, as well as additional elements made of galvanized steel, have been in operation for more than 20-25 years with proper maintenance and timely repairs.
• Corrosion resistance. Zinc layer, polymer coating reliably protect steel from water, because the metal tile does not corrode.
• High bearing capacity. Due to the wavy profile, the metal tile has a high bearing capacity and does not deform under the influence of intense loads.
• Resistant to temperature changes. Temperature drops do not affect the strength properties, the integrity of the material, so it is used in all climatic zones.

Important! It is recommended to lay the metal profile coating on single-pitched and multi-pitched roofs with a slope of at least 12 degrees. For the installation of a cold roof, you will need directly roofing material, as well as additional elements: valleys, ridges, eaves or gable strips, drainage elements, spotlights for filing cornices, lightning protection, snow retainers

The design of a warm roof implies the additional use of insulation and vapor barrier.

The structure of a sheet of metal

Possible sizes of sheets of metal

Ventilation

The relative complexity of the design of a metal roof requires additional measures to ensure sufficient ventilation of the internal spaces of the roof.

Ventilation schemes differ when using cold and warm types of roofing.

Air exits through holes in the roof ridge. With this scheme, it is possible to stop air exchange when an ice crust forms in the internal space due to temperature differences, which makes it not the most reliable ventilation device.

A cold roof makes it possible to build a more extensive and reliable ventilation system. With this scheme, pipes are constructed that pass through the roof and go into the attic. Dormer windows are built on the slopes of the roof. The arrangement of such ventilation is relatively expensive, but the reliability of this system is at a high level.

IMPORTANT!
In a warm roof, the construction of any additional bulky structures is not carried out, air circulation is ensured by the creation of gaps between the insulation and the metal tile, as well as the correct location of the crate.

The main mistakes when installing a roofing pie under a metal tile

1. Measurements and calculation of the required materials must be entrusted to experienced specialists. Otherwise, mistakes made can lead to additional costs for the purchase of missing elements or unnecessary costs for excess materials.
2. When unloading, the metal tile must not be dragged along the ground. The inner layers of the polymer coating are damaged during such handling of the material, which further leads to corrosion of the metal.
3. Sheets of metal tiles cannot be saved, since increasing the length creates additional joints. In the future, they will become a potential source of depressurization of the roofing pie and moisture ingress.
4. Sheets of metal tiles can not be strongly bent. This negatively affects the relief of the roofing. During installation, the joints of the sheets will be uneven. The resulting gaps will cause moisture to penetrate. Visually, these defects are very noticeable, which greatly spoils the appearance of the entire roof.
5. The service life of the outer coating will be significantly reduced if it is installed without a counter-lattice.
6. In the process of erecting a roof, it is necessary to level the crate. An uneven base leads to deformation of metal sheets, the formation of gaps at the joints and a decrease in the service life of the material.
7. In no case should you use a grinder to cut sheets of metal. The abrasive wheel burns through the polymer coating, and hot grains, falling on the surface of the material, spoil it. The same mistake is made by those who use a grinder with an abrasive wheel. Cutting metal tiles with this tool leads to the fact that not only the polymer coating deteriorates, but also the zinc layers are burned through. Subsequently, rusty smudges form in these places.
8. If during the installation the mineral wool slabs are deformed or crushed, then it, having reduced its thickness, will lose its heat-insulating properties.
9. Joints of sheets of metal tiles, junctions of material with chimneys, as well as adjoining windows, must not be filled with mounting foam. Such an error speaks more about negligence than they do about the builder's ignorance of their business. Polyurethane foam is sensitive to ultraviolet radiation, under the influence of which it crumbles.
10. The installation of a metal tile roofing pie is a responsible process, therefore, to attract it, it is necessary to select qualified builders.

Video: how not to fix a metal tile

Compliance with the construction technology, the selection of high-quality materials and the involvement of experienced specialists will make it possible to produce a high-quality roof for metal tiles. These conditions will guarantee the durability and strength of the erected structure.

Materials used

We found out that waterproofing is the most important element of a roof covered with metal tiles. But what should be a high-quality layer that protects against water? The requirements for waterproofing are as follows:

• it must have increased fire resistance;
• pass steam well;
• indicators of strength and reliability should be on top;
• the material should not deteriorate with sudden changes in temperature, be afraid of ultraviolet radiation;
• the layer must withstand a certain level of mechanical stress;
• waterproofing should not be afraid of pest attack or be prone to mold development;
• also, it should cope well with its main tasks and not harm human health.

Laying waterproofing material

Various types of materials can be used for waterproofing. All of them have a lot of differences from each other, including different resistance to light, strength, quality and durability.

For the most part, special roofing films with several layers are used for waterproofing metal roofing. There are reinforcing and absorbent layers. The first provides protection from precipitation, and the second is able to absorb moisture coming from the inside, so that condensation cannot accumulate on the waterproofing and mold pockets form. Also, on both sides, the material usually has a lamination of polyethylene.

Roofing films

Such a coating has special pores that allow the passage of vapors that form inside the house, but at the same time do not allow moisture from the outside to spoil the materials from which the roof is made. This feature of the material, called vapor permeability, is especially important if the attic is converted into an attic and used as a living space.

Conclusion of vapor and waterproofing on the roof, screwing of metal tiles

Advice! When choosing a material for waterproofing, it is important to pay attention to its service life. It should coincide with the life of the metal tile so that you do not have to disassemble the roof and lay the waterproofing again if it fails, and the main roofing material is still usable

Service life of the special film used under a metal tile makes 50 years.

Name	Short description
Standard or Classic	Film with low vapor permeability, for which it is important to equip the so-called double-circuit ventilation, which will be located between the roofing and waterproofing materials, as well as between the film and the roof insulation layer. The gaps between them should be 3-5 cm. The material is ideal for the construction of a cold roof or a roof with a simple design.
Anti-condensate	A material that also requires the creation of dual-circuit ventilation. The film is equipped with a moisture-absorbing fleecy layer that perfectly retains excess water. This is a fairly dense material, rough to the touch, durable and not afraid of exposure to ultraviolet radiation. But the vapor permeability of such a film is low.
Superdiffusion	The best material for roof waterproofing, as it has increased vapor barrier performance and does not require dual-circuit ventilation. It is enough to leave gaps between the film itself and the roofing. Installation of such a film is simple, it has a long service life. The main disadvantage is the high price.

Isover Tyvek Solid Roofing Film

On a note! Common to this day used hydrobarriers, made on the basis of bitumen and bituminous mastic, should not be used for arranging a roof made of metal.

Of course, a cheaper film can be used for temporary roofing, but for capital construction it is better to take high-quality, albeit expensive material. It is not worth saving here and it is better to buy a diffusion membrane coating. All indicators of the purchased film are shown on the edge tape that frames the material. The film is produced in rolls 1.5 m wide and 50 m long. The density of the material is about 140 g/m2. A prominent representative of the material that is optimal for laying under a metal tile is Izospan AM or AS.

Izospan AM

Izospan AS

Insulation of a metal roof with polystyrene foam

Scheme of roof insulation from metal tiles with foam plastic.

Styrofoam has become quite widespread as a heater for metal tiles. In addition to the low price, it has the following properties:

• due to the lightness of the material, insulation does not require additional strengthening of the supporting structures of the roof;
• the insulation is very easy to install, it can be processed with any tools;
• polystyrene is environmentally friendly and does not cause allergies;
• resistant to biological substances, therefore not susceptible to mold or bacteria growth;
• good indicators of resistance to moisture and temperature extremes;
• insulation with foam will last a long time;
• insulation has good soundproofing properties;
• the foamy structure of the foam provides low thermal conductivity, which allows it to perfectly retain heat;
• low price.

Styrofoam can be used to insulate roofs of any structure, but it is best suited for flat roofs. Insulation of complex pitched roofs with foam plastic requires good skills, since when laying, you should try to avoid the formation of cold bridges - seams and joints. In some cases, this result can be difficult to achieve due to the rigidity of the foam. In this case, there is a possibility that condensate may accumulate in the voids formed, as a result of which the roof rafters will be destroyed or corrosion of the metal parts of the roof frame will occur.

Insulation of the roofs of residential buildings should be carried out only with the use of special foam that does not emit harmful fumes when heated and belongs to fireproof, self-extinguishing materials. When determining the thickness of the foam, it is necessary to take into account the thickness of the rafters. If the thermal insulation material is laid in 2 layers, it may be larger than the thickness of the rafters, which will lead to the need to build them up for subsequent finishing.

When choosing a foam plastic for a metal tile, it is necessary to take into account its density, which is the main indicator of the ability to withstand loads. For example, for pitched roofs it is better to use a material with a density of 15 kg / m3 with a thickness of 100 mm, and for flat exploited roofs - PSB-35 foam.

Calculation of the amount of metal tiles

To calculate the required number of sheets of material, you first need to determine the type of profile and the manufacturer of the metal tile - you will need the exact dimensions of the material itself, and each profile has its own. Then it is necessary to make accurate measurements of the slopes - the length, height, if any, it is necessary to measure all the protrusions or other decorative elements that will need to be sheathed with roofing material. If the roof has a complex shape, it is better to draw its plan, put down all the dimensions and then sit down for the calculations.

Number of rows

It is best to look for metal tiles not in stores or markets. It is advisable to go directly to the manufacturer. The point is not only the price - it may not differ very much, but the fact that many workshops / factories offer to cut sheets of the required dimensions. The minimum sheet height is 0.7 m, the maximum is 8 m. That is, you can order the required number of sheets covering the roof slope from the ridge to the overhang (including the ledge).

This option is good because the metal roof will not have horizontal joints, which means there will be less chance of a leak. The second plus is the minimum amount of waste and a smaller amount of the material itself (due to the absence of horizontal overlaps, several square meters are saved). Cons - difficulties with delivery, lifting long sheets upstairs, inconvenient installation.

Calculation of a rectangular roof slope

When using sheets of standard sizes, the height of the roof slope is divided by the useful length of the sheet. The resulting figure is always rounded up. The useful length is obtained after the horizontal overlap is subtracted from the total length - from 100 to 200 mm. The flatter the slope, the greater the overlap of the sheets is necessary so that precipitation cannot enter the under-roof space. On roofs with an angle of inclination up to 12°, one sheet overlaps another by at least 200 mm, with an inclination of 12° to 30°, the overlap is 150-200 mm, more than 30° - 100-150 mm. The specified amount of overlap is subtracted from the total length of the sheet, this will be the “useful length”.

An example of calculating the number of rows of metal tiles on the roof. Let the slope length be 4.5 m, the useful sheet length be 2.3 m. Divide 4.5 by 2.3, we get 1.95, round to an integer - we get 2 rows. In this case, only a small part of one sheet will go to waste, but there are times when more than half is cut off. This is very unprofitable, since you can’t use this piece anywhere else.

Number of sheets in a row

Take the length of the slope and divide by the useful width of the sheet. This parameter is indicated in the technical specifications for the metal tile. Most often it is 110 cm (1.1 m). The resulting number is rounded up, we get the number of sheets in a row.

An example of the calculation of sheets of metal tiles in a row. Let the length of the overhang be 8 m, the useful width of the sheet is 1.1 m. When dividing, we get 7.27 pieces, but we round up to a larger integer and get 8 pieces in one row. Moreover, more than 2/3 of one sheet will go to waste.

Features of hip roofs

In hip roofs, the slopes have a triangular or trapezoidal shape. Here it is necessary to select the length of the sheet - to minimize the amount of waste.

An example of the layout of sheets of metal tiles on a hip roof

The height is chosen so that no more than half goes to waste. It is quite difficult to do this manually, and still there is a solid error - there will be 20-25% more waste than when calculating using programs. They are usually available from vendors and manufacturers. It is better to provide them with an accurate calculation, and at home to pre-measure the parameters of the roof (or call a measurer), and then try to choose the dimensions yourself. Then it will be possible to compare the amount of material needed, calculated by you and proposed.

Determination of the number of additional elements

Roofing from metal tiles requires a large number of various additional elements (additions) that form the ridge, the edge of the overhang, the sides of the slope, the passage of the pipe, the valley (the junction of two adjacent roof slopes). The more complex the shape of the roof, the more the amount of extensions required. With a simple gable roof, ridge elements and plugs, cornice and gable strips will be needed. That's all.

What are the additional elements for a roof made of metal and why are they needed

Despite the wide variety of extensions, they are all considered the same. Take the length of the surface on which you want to mount and divide by the useful length of the element. It is usually standard and is 1.9 m (total length 2 m). The result is rounded up.

Proper arrangement of ventilation

As for this item, metal roofing is simply unique in its kind. With all the effort to make the coating airtight and to protect the roofing pie from atmospheric precipitation as much as possible, there are many difficulties when working with this material. All because of the unusual shape of the metal tile, which allows snow and raindrops to gradually fly under the cover.

And this is already bad for a heater, and for any heater. That is why competent ventilation is needed here, which will immediately bring out such accidentally flown snowflakes or drops. That is why when insulating a metal roof, the only correct option is forced ventilation. Believe me, natural will not be enough.

Additionally, be sure to use a guide. The flow guide is used in eaves. Its main purpose is to direct and remove air from the heat-insulating material, thereby protecting it from possible snow blowing during a snowstorm. On the other hand, the flow guide prevents loose mineral wool from spilling over the eaves or roof vents.

This unusual product is made from impregnated moisture-resistant cardboard. Izover air guides are designed for rafters that come in increments of 90 or 120 cm, but if you wish, you can also cope with a non-standard step

Pay attention to the photo of this step-by-step instruction for insulating a metal roof - the pink unusual detail is the flow guide:

Metal roof top layer

As the roof itself is a certain completion of the structure, so material such as metal tiles is the top part of the roofing pie.

Important! Competent professional installation of high-quality metal tiles, which have high quality characteristics, is a guarantee of the most efficient operation of the roofing. This material is able to serve without loss of quality for a huge number of years, the roof will delight every owner of the house for a long time.
.

Modern professional manufacturers of this material guarantee that the total service life of metal tiles, subject to all installation and application standards, can reach 50 years. This attracts a large number of developers, and also determines their choice.

An important element that is responsible for the quality and practicality of the roofing cake, which is directly responsible for the tightness of such an element as a roof, is such an element as a sealant. It is installed on special skates, to such elements as wind, valley and special wall strips.

Important! It is required about twice a year to carry out the most thorough inspection of the entire surface of the roof for preventive purposes.

Particular attention must be paid to all additional elements present, structural joints and some kind of adjoining.
.

Important! All materials used must be qualitatively calibrated and very well dried, strictly in natural conditions. Before equipping the crate or counter-crate, the materials used are best treated with special antiseptics and substances such as flame retardants.

Scheme of the device of a roof from a metal tile.

A shed unloaded roof can be insulated with slabs of increased rigidity. For a gable roof, in some cases, insulation with materials of low density is allowed, but with a one-sided foil surface. It is especially convenient to use such products in the thermal insulation of the attic. The roof is upholstered on the inside so that the foil is on top - the heat will be reflected and partially returned to the room.

A properly insulated roof is a multilayer structure:

• protective film;
• thermal insulating material;
• waterproof membrane;
• crate of wooden slats;
• layer of metal.

After 5-6 years, new insulation will be needed, which will entail extra costs. Therefore, it should be remembered: compliance with the technology will help to avoid mistakes when insulating the roof and save a lot of time and effort, and properly selected materials will provide heat in the premises for many years. Roofing from metal tiles - the best solution for your home! In the next article - how to insulate ventilation on a metal roof.

• home

Creating a ventilation space

Ventilation under the roof- a mandatory element, since it serves several purposes at once:

• removes moisture accumulating under the roof;
• prevents the formation of icy areas and equalizes the temperature over the entire surface in winter;
• prevents the penetration of street heat in hot weather.

A special ventilated roof ridge is designed to remove air, and air inflow occurs through the overhang of the eaves. If you do not properly install the ventilation system, you will soon encounter the problem of high humidity, and as a result, the structure will quickly become unusable.

Metal tile on roofing material

A common version of the substrate for metal roofing is roofing felt. Such material can be used for an uninsulated attic.

This scheme has a lot of advantages:

• roofing material - inexpensive substrate which will significantly save your repair costs;
• substrate mounting does not require special skills and abilities;
• roofing material - popular building material so you can buy it everywhere.

However, for high-quality installation of metal tiles on roofing material, it is necessary follow certain rules:

• in no case should sheets be laid directly on the roofing material, this creates favorable conditions for the displacement of the structure. It is necessary to make a crate in two layers: 1 - along the roofing material, 2 - under the wave of the metal tile;
• as an alternative, you can fill the usual slats along the installed rafters;
• to prevent fire and simplify the ventilation of the room, it is worth building ventilation holes.

Roofing is best left to the professionals. However, if you are determined to do all the work yourself, then carry them out in accordance with the established requirements. Only in this case, you can get a durable and reliable design.

pitched roofs

Advice. Pitched roofs can be insulated from the inside when vapor and waterproofing has already been laid. Do-it-yourself warming is best done at the time when the roof is being built.

Pitched roofs are, as a rule, a supporting frame system, which includes rafters, a mauerlat, a ridge, a crate, struts and other elements. The bearing parts of the system are usually made of metal profiles or wood. In such a multilayer structure, the thermal insulation layer is placed inside the supporting frame. Glass wool, lightweight mineral wool slabs are best suited for warming a pitched roof.

Installation procedure and features

Before you cover the roof with a metal tile with your own hands, you need to familiarize yourself with the rules for working with the material:

• First of all, you need to take care of proper storage - in ventilated stacks, arranged in bars.
• When cutting, do not use an angle grinder (grinder), but cut only with a jigsaw or scissors for metal. The grinder overheats the metal, due to which the zinc evaporates, in the places of the cut the material will begin to rust.
• Start laying the sheets from the lower right corner (the installation diagram of the metal tiles is in the photo below).
• When mounting, wear soft, well-fitting shoes, step only in the lower part of the wave.

How to cover the roof with metal tiles: rules

Next, we will talk about the device. Metal roofing comes in two versions: with a cold or insulated attic. Depending on the type chosen, the order of work changes - when arranging a warm attic, two more layers are added - a heater and a vapor barrier membrane from the side of the room.

Cold metal roofing

This type of roof is suitable if the attic is planned to be non-residential. Then all the insulation is concentrated in the ceiling, and the function of the roof is only to protect from rain and wind. The order of work is as follows:

• The first lath of the crate (higher) is installed along the overhang.
• A drip bar is attached to it.

A waterproofing membrane is spread over the rafter legs. Installation begins from below, the film is rolled out along the overhang. The lower edge of the film comes to the drip bar, ending after the inflection line. The film is fastened with planks 30-35 mm thick to each rafter leg, not in tension, but with obligatory sagging of 2-2.5 cm. The second row of the film overlaps the first by at least 15 cm, the joint is glued with a special adhesive tape (sold in the same place where and membrane). The membrane is attached to the drip bar with self-tapping screws (galvanized or stainless steel).

Cold roofing from metal tiles: settlement of layers

• Boards (bars) of the crate are attached to the planks that hold the film with the selected step. Use galvanized or stainless steel screws, the same nails with a large flat head. The length of the self-tapping screw and nails is three times the thickness of the battens.
• Sheets of metal tiles are laid on the crate, exposing them strictly along the overhang (if you have it exactly horizontally). Neighboring sheets overlap in one wave, installation is carried out from the bottom up, with the obligatory horizontal overlap by the required amount (see above).
• Mount ridge elements, end strips. They are fixed with the same self-tapping screws as the metal tile, in increments of 10 cm.

Warm roof

When constructing an insulated roof made of metal tiles in the roofing cake, another heat-insulating material is added, which is fixed between the rafters, and a vapor barrier film, which is stuffed onto the rafters from the attic side. Further, the entire installation process is similar.

Scheme of the device of a warm roof made of metal tiles

How to attach sheets

When we cover the roof with a metal tile, we must correctly position the screws. There are several rules to follow:

• Self-tapping screws are installed in the lower part of the wave, 2 cm below the step.
• The bottom row, along the overhang, is attached to each wave. Fasteners are also installed in places of horizontal and vertical joints.
• The waves between the horizontal joints are fastened through one in a checkerboard pattern.

These rules are clearly shown in the diagram. In a graphic image, some things are easier to understand.

The scheme of fastening metal tiles with self-tapping screws

Cold or warm roof

There are two types of roofing using this material, which differ in their characteristics. Insulation is not used in a cold roof; it is suitable for those cases when insulation can be laid in the attic floor. A warm roof is made in cases where the living space is located directly under the roof.

cold roof.

Two layers of materials are used - waterproofing (to protect the interior from possible condensation) and metal tiles. Both layers are separated from each other by a counter-lattice and a crate, ventilation is made at the junction of the slopes. For waterproofing, PVC or a thick film is used, the full tension of the material should not be allowed, the film should sag by about 25 mm, which improves moisture drainage. The waterproofing layer is attached to the rafters and fixed under the crate.

It is used in houses where the attic space will not be used as a dwelling.

Warm roof.

The basis of this type of construction is a heater, which additionally performs the function of sound insulation. For this, various types of insulation can be used. The thickness of the insulation depends on the characteristics of the building and the climate of the region, mainly its layer is not less than 15 cm. Another important indicator of the insulation is fire resistance. Thermal insulation is located in the space between the rafters, a vapor barrier layer is used below the thermal insulation and waterproofing. Small gaps are made between the layers to ensure ventilation. All layers must simultaneously be sufficiently dense (so that there are no voids where moisture accumulates) and not thick (so as not to interfere with ventilation).

This scheme is used to equip a warm room under the roof.

When purchasing materials, it is necessary to maintain the cross section of the boards so that repairs do not have to be carried out in the near future. For the arrangement of the roof, metal roof tiles, additional elements, boards, self-tapping screws and other consumables are purchased. The price of the structure will depend on the type of coating chosen, insulation, size and shape of the roof. The average cost of one meter of a roof is 1-1.5 thousand rubles. The calculation of the amount of materials must be left to qualified craftsmen.

The shape of the roof plays an important role in pricing
On our website you can find contacts of construction companies that offer the service. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

The question of waterproofing and ventilation

The metal has a high thermal conductivity. This means that in the warm season it will heat up like a frying pan, and freeze in winter. You can somehow put up with the high temperature in summer. And in winter, a cold roof will eat up a lot of heat, which is fraught with large bills for heating the house. Due to temperature fluctuations, already in autumn, when it is cold at night and still warm during the day, a huge amount of condensate forms. Smudges are formed that flow under the coating and threaten the thermal insulation material. Even if the roof is insulated, the heat-insulating material may get wet, which will eventually cease to fulfill its functions.

Therefore, the main point in the installation of a warm roof made of metal is the creation of a waterproofing barrier that will protect the heat insulator from smudges from the inside of the metal coating.

The hydrobarrier is a special reinforced membrane that covers the roof slopes. Its function is to protect the heat-insulating material from accidental leakage of water from rain and snow and from condensate, which is an integral part of a metal roof.

It is not enough just to protect the heat-insulating layer from smudges. It is necessary to provide that the roof structure is provided with good forced ventilation, due to which all condensate will be vented to the outside.

Waterproofing device with polypropylene film

An alternative option for waterproofing a warm roof with a metal tile coating can be a two-layer waterproofing polypropylene membrane. On the one hand, such a coating has a layer of non-woven material that absorbs condensate. On the other hand, there is a hydro-barrier with ventilation pores, through which drops of formed water will come out. Such a membrane is laid with the first layer inside, where the thermal insulation is located, and with a hydrobarrier - to the outer layers of the roof.

Two-layer polypropylene film designed specifically for roof waterproofing

Super diffuse coating

The super diffuse membrane is one of the latest developments in the field of waterproofing and building materials in general. It resembles leather in properties, and the development of such a coating came from the textile light industry - membrane materials in sportswear have been used since the middle of the last century.

They differ from ordinary polypropylene films in the number of layers - there are up to four of them in a superdiffuse membrane! All layers have pores in their structure through which condensate drops are removed. Layering ensures the resistance of the membrane to stretching. The last outer layer of the coating has a UV filter.

Superdiffuse membranes - the latest in roof waterproofing

Superdiffuse coatings are produced in the form of a roll and in the form of mastic. The second type is also called "bulk roof". It is considered more economical than rolled, but loses in vapor barrier properties. And, due to its consistency, its use is allowed only on horizontal surfaces. Additional complexity is created by the surface coating technology - the mastic layer must be uniform, and this task is difficult to cope even with professionals. Therefore, in private construction, they use roll modification more - they can handle its installation on their own.

The advantage of the super-diffuse coating is that it can be used as a temporary roof protection before installation of metal tile sheets on the insulated roof. This greatly facilitates the construction of a roof with other coverings, as is the case with soft tiles.

The choice of material for insulation

Thermal insulation materials for metal roofing are quite diverse, but the most popular are polystyrene foam, polyurethane foam and mineral wool. These heaters are lightweight, which means that the pressure on the floors will be minimal. In addition, they are environmentally friendly, easy to use and serve for a very long time, provided that the thermal insulation is laid in compliance with the technology. If the metal roof is insulated somehow, even the most modern and expensive materials will not help.

It should be borne in mind that the thickness of the heat-insulating layer of the roof should not be less than 15 cm and exceed 25 cm.

Scheme of a metal tile.

Most often, mineral wool boards are chosen as a heater for metal tiles. Cotton wool in rolls is also suitable, but it is not so convenient to lay it, so the plates can be called an ideal option.

As practice shows, thinner insulation will not provide good thermal insulation, and too thick a layer will put extra pressure on the floors, and the roof will become less reliable. To correctly calculate the required amount of material, you need to multiply the total roof area by 0.2.

Substrate varieties

The substrate for the metal tile must be selected depending on the purpose of the attic space.

There are substrates for cold rooms and there is a substrate for residential, that is, heated premises. There are certain requirements for substrates for residential premises (such as an attic), and others for a cold attic.

Underlayment for a cold attic is much simpler than for a heated attic. A counter-lattice is attached to the rafters, and a crate is attached to it. Between them leave free space for air circulation.

A film is placed on the crate to protect wooden structures from moisture, which penetrates into the attic through leaks in the tiles.

For a warm attic, the substrate design looks different. The crate and the counter-crate are also attached. But more stringent requirements are imposed on waterproofing. In this case, it should not only protect the attic from moisture from outside, but also from condensate, which forms on the inner surface of the metal tile due to the temperature difference between the outside air and the inside.

Functional diagram of a roofing pie for a warm metal roof.

On top of this, the waterproofing film must ensure the removal of water vapor rising from the lower rooms so that the insulation remains dry and does not lose its qualities.

An air space of 2 to 4 cm is left between the waterproofing and the insulation for air ventilation.

Depending on the climate in your area, choose the insulation material and its thickness. Below lay the film for insulation. And already on top of the film sheathe the living space at the request of the developer. This design is called a "roofing pie". It is optimal for protecting the roof structure from external and internal adverse conditions.

The structure of the roofing cake for metal tiles, including waterproofing

Covering a cold attic with a metal tile is the most convenient and easiest way to equip a roof. In this case, the roofing pie will consist of a waterproofing material laid on the rafter frame, battens and roofing (metal tiles). Actually, the laying of such a coating is carried out very quickly. The insulating film is fixed with staples or nails, then it is additionally pressed with a counter-lattice screwed with self-tapping screws. The lathing of the battens is carried out taking into account the dimensions of the metal tile. The board for the crate is taken with dimensions of 25-100 mm, and sometimes plywood or particle boards are used if continuous flooring is required.

Laying a film or membrane for attic waterproofing is done freely, with some sagging. However, it is worth making sure that the integrity of the coating is not violated, that is, any holes or cracks are excluded. As a rule, the film can sag by 15-25 mm. Thus, ventilation of the inner side of the waterproofing membrane is achieved, removal of condensed moisture to the eaves and further to the drain is ensured. Neglecting such a simple rule will eventually provoke premature deformation of the roof frame and the entire roof.

The peculiarity of a metal roof is such that the film for a cold roof is not able to reduce the noise level that occurs during intense rain falling on the metal. Therefore, living quarters with such roofing are provided with a layer of thermal insulation that absorbs strong noise. Without such a layer, only non-residential attic spaces are usually equipped.

So, a cold roof will include the following layers:

• From the inside of the room, a vapor barrier is laid for a cold roof, which only releases moisture to the outside and prevents it from penetrating into the living rooms.
• Next, install the truss frame for the roof.
• The next layer is mounted waterproofing material. The film is laid with sagging to drain condensate.
• Next, a counter-lattice is attached, which presses the waterproofing, fixing it, and provides ventilation gaps.
• Then the crate is stuffed to fix the roofing. It is made of slats 50 × 50 mm and is laid along the slopes with an indent of 35-45 cm. Based on the type of roofing and the slope of the slopes, the step of the crate and the thickness of the board for it may vary.
• The last is the metal tile flooring.

Roof insulation pie made of metal tiles without counter-battens

The lathing, fixed to the frame of the truss system without a counter-lattice, tightly presses the elements of the roofing pie, leaving no gaps for ventilation of the structure. In this case, only horizontal openings remain between the battens of the crate. This is not enough, since warm air and steam will rise, and tightly pressed structural elements will prevent this process. As a result, all the evaporated moisture will settle on the wooden elements of the frame, and in case of damage to the vapor barrier layer, inside the insulation. This will lead to the fact that after the first winter the wood will begin to rot, and the insulation will become unusable.

The counter-lattice just creates the required distance between the rafter system and the roofing pie, which allows ventilation of the entire frame. In this case, the water will not linger and settle on the structural elements, but together with the flows of warm air it will go outside.

Even if all the layers of the roofing cake without a counter-lattice are already installed on the rafter frame, the situation can be saved. To do this, wooden bars with a section of 20x40 cm must be fixed to the inside of the rafters parallel to their edge. From above, using a stapler, fix the vapor barrier membrane. In this case, the necessary distance for ventilation is formed between the vapor barrier and the insulation.

If there is no ventilation gap in the roofing cake, moisture does not evaporate, but settles on wooden structures and insulation

Roof insulation

For high-quality thermal insulation of the roof of a structure such as an attic or a residential part of an attic, the following modern finishing materials should be used:

• Special basalt materials as insulation;
• High-quality semi-rigid insulation, which belongs to the semi-rigid category;
• Mineral quality insulation;
• Ecowool;
• Quality glass wool
• High quality extruded synthetic polystyrene foam.

All such materials that provide thermal insulation are characterized by a low degree of thermal conductivity, but are leading in the arrangement of roofing insulation. This is based on a large number of specific indicators.

How to make waterproofing

When insulating a roof covered with metal tiles, be sure to install a hydrobarrier. This is a special reinforced vapor-permeable film that protects the attic space from condensation, dust and accidental rain or snow.

Pay special attention to the first problem - it is on the metal tile and on the corrugated board as a metal material that condensate quickly accumulates. After all, the metal always heats up quickly and cools down just as quickly, creating a significant temperature difference between the object and the air - ideal conditions for water vapor to settle in the form of drops.

When the condensation of steam reaches a critical point - the dew point - the water molecules in the air bind and turn into water. The main conditions for this are high humidity in the room and temperature difference. Plus a poorly arranged vapor barrier, of course. And thanks to the micro-perforation of modern hydro-barriers for water vapor, a small ventilation will be created, which will help such drops evaporate faster. Good budget option.

Polypropylene films with an anti-condensation layer are also suitable for solving a similar problem. One side of such barriers is made of non-woven geotextile, and the other side is waterproofing. The textile insert of such a film adsorbs moisture and steam and removes them through the ventilation gaps. What is good, such a film can be left on the roof without roofing for quite a long time, which is why work at height is calmer.

And finally, new superdiffuse membranes. Their use allows you to make only one air gap between the film and the roofing - and all the condensate will come out by itself. This is wind protection, insulation protection, and effective removal of steam from the entire roofing pie. In addition, the membrane itself can be laid directly on the insulation without any additional battens - valuable savings! See what a modern membrane looks like and how it differs from ordinary polyethylene film even in appearance:

But when buying a good roof membrane, you may have difficulty. Even if you contact the official dealer of some manufacturer with a memorable advertisement, it is not a fact that in the end you will end up with a quality product. Sometimes unscrupulous sellers offer to look at advertising samples of films that have a noticeable rough structure and a certain color, look, but in the end they sell a roll of film with slightly different qualities. At the same time, when buyers try to deal with the "forgery", they refer to the legal right of the manufacturer to change both the color and texture of the products at their discretion. Those. one thing is advertised, another is sold - not often, but this happens periodically on the construction market.

Therefore, when purchasing a superdiffuse membrane, be sure to check it for the following key characteristics:

• Vapor permeability: 0.02-0.03 m.
• Tensile strength: not less than 140 N/5cm.
• Pull-out strength: not less than 50N/200mm.
• Water resistance: W1 degree, and the water column is greater than 2000 mm.
• UV stability: 3 months.

According to these characteristics, membranes are divided into certain groups. Some can be placed directly on the rafters, others can only be in contact with the insulation. And the tear and tear strength is the durability of the film itself.

Roof waterproofing

The process for such material as metal tiles is carried out with all types of roofs, that is, insulated or not. Installing a waterproofing membrane is able to perform the following functions:

• Protection against a large amount of condensate that accumulates on the insulation;
• Effective protection against the presence of a large amount of moisture truss systems. Waterproofing the entire attic or attic.

Important! The film used should contain small holes that are designed to create an effective ventilation air exchange in the installed
system.

The modern market offers a diverse range of high-quality films designed for metal tiles. Despite this, effective waterproofing of roofing on pitched roofs can only be carried out using special membranes.

Such demand is based on high anti-condensation properties. The density level of the film and its fire resistance and UV resistance must be selected with full regard to the operational characteristics of the roof.

The process of fixing the membrane is carried out using a special stapler with special staples and strictly to the truss system. A crate is mounted on top of the film, but it should sag no more than 2 cm, thereby providing the necessary ventilation gap that the roof needs.

Installation of additional elements

The installation of a roof made of metal tiles does not end with the laying of roofing material. To make the structure more durable, protected from atmospheric moisture and complete, it is tedious to install valleys, a ridge profile and cornice strips. Work is performed in the following order:

1. Install the ridge profile. The op is attached to the crate along the ridge connection with roofing screws. To protect the ends of the profile from water ingress, a special sealant is used.
2. They fix valleys and other grooved elements. To protect the joints between the slopes and the junctions with vertical surfaces, special strips are installed.
3. Eaves and gable overhangs are equipped with special strips that protect against moisture and wind.
4. Eaves and gable overhangs are sewn up with soffits. These perforated panels protect the underside of the ramp, which is not protected by waterproofing, from contact with water.
5. Install a drain, snow retainers and lightning protection.

Remember! Valleys, ridges, junction strips and drains are not decorative elements of the roof. They perform the function of protecting the canvas from leaks, sealing it. Provided that the roofing pie is properly equipped and auxiliary components are used, a metal roof will last 20-30 years.

Additional elements for roofing for metal tiles

Metal tiles are used to cover pitched roof structures. It is laid on the supporting frame of the roof - the truss system. Metal roof insulation it is recommended to carry out using a roofing cake made between the rafters. This technology is considered the most efficient and gives excellent heat saving results.

We can say that in the end, the maximum provision of heat preservation depends on the filling of the pie. Properly selected and installed, it prevents the attic and attic living quarters from cooling down, does not allow moisture to penetrate from the outside and ensures its removal directly from the cake itself.

The main layers of the roofing cake

It is impossible not to note the roofing material itself - metal tiles. The extent to which the roof and the elements of the “stuffing” of its roofing pie will be protected from the aggressive effects and physical exertion of natural phenomena, snow, rain, and wind largely depends on the observance of its laying technology. Safety, lack of wetting and efficiency of the heat-insulating layer provide waterproofing film, one or two ventilated gaps (depending on the type of waterproofing material) and vapor barrier material.

Metal roof waterproofing designed to prevent moisture from entering the outside. Depending on the purpose of the attic space, it can be both vapor-tight and vapor-permeable.

The waterproofing film is attached to the rafters in their upper part using staples or galvanized nails. In this case, it is necessary to allow a slight sagging of the canvas up to 1 cm in order to protect it from temperature changes. The canvases are laid across the roof slope with an overlap of the upper canvas on the lower one by 10 cm. It is desirable that the waterproofing material has a high vapor permeability, otherwise another ventilated layer will have to be provided in the roofing pie.

On top of the waterproofing layer along the rafters, bars of the counter-lattice are laid, and the bars of the crate are laid across. The height of the bars of the counter-lattice is chosen based on the length of the roof slope and the size of the required ventilation gap, and the step of the batten is selected in accordance with the horizontal wavelength of the metal tile, since roofing material will be attached to it.

For a roof made of metal, it is especially important to have ventilation for the under-roof space. In its absence, condensate, which forms when the difference between internal and external temperatures on the inside of the metal tile, can lead to disastrous consequences for the roof structure.

For metal roofs, including those made of metal tiles, it is necessary to use special membranes - anti-condensation.

This material is one-sided, and it should be laid with the rough side to the insulation.

Heat-insulating layer of a roof from a metal tile it is recommended to arrange from breathable materials, as a rule, with a fibrous structure. They are based on basalt or fiberglass. These heaters have good thermal insulation characteristics and perfectly dampen noise. Another advantage is that they are not flammable. The total thickness of mineral wool layers under the metal roof of an energy-efficient house is at least 20 cm. Fiberglass insulation, due to its structure, has many air gaps, which ensures their low thermal conductivity.

In general, the performance characteristics of mineral wool and glass fiber are similar, although the thermal conductivity of glass fiber is lower.

Penoizol is also used as a heater - liquid foam, a heat-insulating material of a new generation.

The thermal insulation mats or boards must be semi-rigid. So they will hold well in vertical and inclined planes.

Their length should be 2-3 cm more than the distance between the rafters. The number of stacked layers of insulation is calculated depending on the thermal conductivity of the material used for insulation.

Metal roof vapor barrier protects the insulation from moisture that comes from the inside. It is also attached to the rafters, only from below, using galvanized nails or staples. Similar to laying a waterproofing film, an overlap is performed. In order to ensure tightness, all “dangerous” adjoining areas, for example, to walls, pipes, windows, are glued with special adhesive tape.

The device of the roof, insulation and other elements is carried out without deflections, gaps and irregularities with a snug fit to each other, with the exception of ventilation ducts.

2018 stylekrov.ru

Choosing the right heater

Here we come to the main question. For convenience, let's break it down into separate important points.

Sorption humidity of the insulation

Do you know why wet insulation quickly loses its thermal insulation properties? The fact is that the thermal conductivity of water is exactly 25 times greater than that of air - this is one, and the water itself, as it were, glues the fibers together - this is two. That is why, when choosing a roof insulation, carefully study its three main qualities: sorption moisture index, vapor permeability and water absorption. Indeed, at a roof with a metal tile as a roofing, the issue of dampness is acute. Not to mention the constant condensate on the metal surface, which always finds a way to get to the insulation through invisible gaps in the waterproofing.

So, sorption moisture is the hygroscopic moisture of the insulation under certain conditions. Those. the higher this value, the worse, because water-repellent properties are primarily important for roofing insulation. And they are already directly affected by the presence of special hydrophobic additives in the material.

For clarity, let's take a look at the issue of humidity in an ordinary house separately. So, according to sanitary requirements for residential premises, normal humidity is 30-45%, and 30% is the threshold below which the air becomes too dry and even unhealthy. But in European countries, 45-60% is considered normal humidity. But keep in mind that the humidity level in the house can reach 80%, especially if far from two people live together and the wall decoration is almost vapor-proof. Moisture simply has nowhere to go, and it rises up to the roof, from where later there are problems with insulation, if you think over the roofing pie well. Do you remember how a metal roof likes to collect condensate under it?

Of course, all responsibility can be immediately shifted to the vapor barrier. So, for example, aluminum is considered one of the best:

Water absorbing properties of insulation

But you have to upset you a little: not a single vapor barrier in the world can protect the insulation by 100%. The real figures are completely in the range of 70-80% if the vapor barrier is of high quality, and 50-60% if the simplest

And, if we take into account the moment that such a heater is still affected by condenser moisture from the other side (again, a metal tile), then both high-quality vapor barrier and a heater are needed, which, as far as possible, is not afraid of water and retains its properties for a long time even under such extreme conditions.

And this is already such a quality of insulation as water absorption - this is the disposition of the material to absorb moisture upon contact with water and retain it. The lower the water absorption of the insulation, the better - so it will be dry for as long as possible even with high dampness. Styrofoam in this regard, for example, is a leader among other heaters.

So, in addition to foam, stone fiber naturally has water-repellent properties, which only slightly have to be strengthened. Here is a step-by-step instruction on how to insulate such a roof with them:

Insulation vapor permeability

And, finally, vapor permeability is the ability of the insulation to pass water vapor through itself and bring them outside, into the ventilation opening. This is one of the most important factors that affect the thermal insulation of the roof. And in such a roofing cake, vapor permeability should also be on top!

Modern ecowool in this regard is one of the best:

The purity of the insulation

There is another problem: some heaters are dusty, and their lint particles, together with warm air, rise and gradually clog the vapor-permeable holes. As a result, over the years, the quality of even the best "breathing" membrane deteriorates. And therefore, it is better not to insulate such a roof with sawdust at all, as with cheap mineral wool. Only from well-known manufacturers!

And in this regard, special under-tile fastening systems are well suited, which are just beginning to appear on the Russian market, but have long been recognized abroad:

To summarize: the lower the water absorption and sorption moisture, and the higher the vapor permeability, the better the thermal insulation qualities of the material for insulating a roof made of metal. Choose the right material, study our photo instructions - and go!

Roofing pie under the metal tile

The device of a cold roof under a metal tile is one of the simplest options. In addition to load-bearing structures, such a roof includes roofing material in the form of metal tiles, a crate, and a waterproofing layer. The installation of such a roof is very simple: a waterproofing film is attached to the rafter system using a construction stapler or small galvanized nails. After that, it is pressed with self-tapping screws on wood, with which the counter-lattice will be attached, the step of which depends on the type of metal tile sheet. The size of such boards should be 25 by 100 mm, in some cases a continuous coating of plywood or chipboard sheets is used.

The scheme of the roofing pie.

A waterproofing film (it can be a special PVC membrane or a polyethylene film) should be laid on the roof with a slight sag. At the same time, gaps and other defects are unacceptable on it. The level of sagging of the roofing film should be from 15 to 25 mm. This will ensure proper ventilation of the underside of the waterproofing, removal of condensate from it to the eaves, and then to the gutter. If this is not done, then the roof structure will be subject to the negative effects of moisture, and this will lead to destruction.

When installing a cold roof made of metal, it must be remembered that the metal sheet and a thin layer of waterproofing do not provide adequate protection against noise, which can occur during heavy rain. It is for this reason that cold steel sheet roofs are rarely made without insulation, which acts as an excellent sound insulator. The cold attic therefore turns out to be unused.

The structure of such a roof includes the following mandatory layers:

Scheme of installation of a roofing pie.

1. From the side of the residential premises, first there is a layer of vapor barrier with one-sided permeability, that is, condensate is released from the room, but does not penetrate inside.
2. Roof truss system, longitudinal runs, that is, the supporting structure.
3. Waterproofing. The film should sag a little to allow condensation to escape.
4. A counter-lattice, the installation of which is carried out parallel to the installed rafters. The boards of the counter-lattice press the waterproofing, providing its additional fastening.
5. The lathing of the cold roof is made of a wooden beam, the cross section of which is most often 50 by 50 mm. Its installation is carried out in increments of 35-45 cm along the slopes. The step may vary, as well as the material for the crate, it depends on what type of metal tile is used, what slope for the roof was chosen.
6. Sheets of metal tiles.

What else is required?

To install a roof with such a design, it is necessary to take the simplest tools and materials that do not differ in high cost. In addition to wooden boards for the device of the truss system, battens and counter battens, a vapor barrier, a waterproofing membrane, and an estimated number of metal tile sheets should be prepared. Staples, galvanized nails, self-tapping screws for wood and metal are used as fasteners. When calculating steel sheets, it must be remembered that various additional elements may be needed, for example, ridge tiles, valleys, cornices, and so on.

The device of a cold roof differs from a warm one in that in this case a layer of insulation is not used, that is, there is no layer of insulation between the vapor barrier and the waterproofing membrane. Such roofs are applicable in the case when the attic space under them is not used.

Drain organization

If you plan to equip the roof with a drain, then cornice boards should be used to reinforce the slope. They are laid along the overhangs in the grooves made in advance in the rafters. It is to these boards that hooks should be attached to fix the gutter, correlating their step with the step of the truss system.

If the organization of an organized drain is not included in your plans, then a frontal board, which is attached to the ends of the rafters, is used to fasten the roofing elements along the edges of the roof. Such an end plate serves not only as a decorative element, but also prevents the metal tile from rattling during strong winds.