One of the most important measures during any construction is the reliable sealing of the roof. Much depends, of course, on the quality of the roofing and the way it is installed.

But this alone is not enough - all at least slightly vulnerable areas must be carefully insulated from moisture.

For this, there are special hermetic compounds for. A competent choice of the right tool will ensure the proper treatment of any type of roof. After its application, the roof will not allow moisture to pass through, it will be more durable and maintainable.

There are various types of sealants. They are used in the process of repair and planned work, as well as during construction.

These can be completely different construction and finishing activities:

• sealing seams between individual elements, for example roofing sheets, especially for roofs with a slight slope;
• elimination of cracks near ventilation shafts, chimneys and gutters, antennas and other objects that violate the integrity of the coating;
• liquidation;
• insulation of joints between the roof covering itself and other materials;
• sealing of inclined skates;
• quick disposal of leaks.

All existing sealants are conventionally divided into six main types. Let's consider each of them in more detail.

1. Tape

What are the main advantages of tape sealant? After all, this product is one of the most effective and inexpensive for roof protection.

This material has many advantages.:

• excellent moisture resistance;
• good elasticity;
• affordable price;
• the ability to paint to match the overall color of the roof;
• durability and excellent strength;
• excellent grip on dry and wet surfaces.

This type of sealant is most often used for working with a metal roof (etc.), roofing material, etc.

Their disadvantages are poor resistance to high temperatures and rather high toxicity.

3. Silicone

These are various viscous plastic pastes, for which binders are combined with various finely dispersed fillers (soot, graphite, talc, etc.) and special additives.

Depending on the components included in the composition (rubber, resins, plasticizers), a mastic of one quality or another is obtained that has the required characteristics. For waterproofing, bituminous mastic is mainly used, and as its more expensive analogue, polymer.

The latter has higher adhesion properties and, moreover, it is more elastic. It is more preferable for soft mounting (roll materials). Before applying any mastic, the work surface must be well cleaned of dirt and dust.

Sealant selection

How do you know which sealant is right for each individual case?

The different types of sealants differ markedly in their performance characteristics. Some types may be ideal for a certain type of coverage, and practically unsuitable for a completely different one.

Consider the most popular of them, suitable for different types of roofing.

Metal roofing sealants

This type of roofing requires products with the following qualities:

• reliable adhesion to metal;
• high rate of elasticity;
• good vibration resistance;
• resistance to atmospheric precipitation.

These characteristics are most consistent with bitumen-rubber sealants and polyurethane, which throughout the entire operating period are able to maintain high plasticity. Before starting work on the processing of the metal coating, the places where the substance is applied must be well degreased and dried. In the event that the roof needs urgent insulation, a composition that can be applied to a damp surface is best suited.

It is important to know that the use of silicone insulation on an iron roof can be an immediate cause of rust.

In terms of its qualities, the corrugated board is very similar to metal tiles.... Therefore, their sealing is carried out in a similar way. The most acceptable roof slope should be 14 degrees. Special attention should be paid to the transverse joints of the profile sheets. For such a roof, sealants based on silicone and polyurethane are most suitable for their performance characteristics.

Roof sealing made of corrugated board

In order to carry out competent sealing of a roof made of corrugated board, it is important to do the following.

1. Before starting the procedure, check the joints - you can only work with dry and clean surfaces.
2. Apply sealant to the covering of the corrugated board in a uniform layer with a thickness of about 3 mm. You can use polyurethane tape.
3. All activities are carried out at a positive temperature and with a relative dryness of the air.

Metal roof sealing

When choosing a sealant for, for all its similarity to corrugated board, it is important to consider the following:

1. the best end result is obtained with silicone with increased UV resistance;
2. silicone sealant is suitable for gaps no more than 5 mm;
3. do not forget to mix the ventilation outlets, the edges of the pipe apron, the antenna outlet, the longitudinal and transverse joints of the roofing carpet itself.

Soft roof sealant

Or, in other words, soft tiles have always been considered a highly demanded and popular coating. For its large-scale sealing, one of the types of mastic is usually used.

In other cases, many additional factors are taken into account, for example:

• special sealing roofing tapes are excellent for eliminating joints and seams;
• if the roof is almost or completely flat, then an emulsion is suitable for it;
• for local repair of individual defects and leaks, it is good to use an elastic waterproof compound;
• The mastic is well applied to any surface, even wet, has excellent adhesion to a variety of materials, does not form blisters.

When choosing the roofing sealant you need, read all the labels on the packaging.

It indicates the possibility of curing in a humid environment, the speed of setting, compatibility with other materials, the possibility of subsequent painting, resistance to atmospheric precipitation.

These are all important to you, so pay attention to them. A competent choice will help you choose the right composition for insulation, and precise adherence to technology guarantees the reliability of the protection carried out. To do most of the work on your own, theoretical knowledge and a little practical experience are usually sufficient.

If you still have doubts, consult a specialist. They will be able not only to give advice on which product is suitable in a particular case, but also, if necessary, perform reliable and high-quality waterproofing themselves.

For complex roofing systems with a large number of various engineering communications on the roofs, the use of a sealant is mandatory. Only with its help it is possible to guarantee not only the complete tightness of the coating, but also its long-term operation. In addition, these materials are used during emergency repairs, with their help, various leaks are eliminated. On roofs, you often have to work in difficult weather conditions, such features of use put forward terrible requirements for sealants in all physical parameters.

Each type of material should correspond to its purpose as much as possible. During the development of the composition, scientists take into account not only this factor, although it plays an important role during the preparation of the technical specifications for scientific development. It is necessary to take into account the specific operating conditions, the responsibility of the roof, ease and safety of use. It is recommended to use sealants when performing the following types of work.

Type of work	Description of activities and quality requirements
	Such a need arises if slopes with a slight slope are covered, and it is impossible to use soft roll roofs. Very complex multi-gable roofs have slopes at different angles, all of which must be covered with the same type of roofing material. If some destinies have too little slope, then their joints and abutments of roofing materials must be specially sealed. This is the only way to prevent leaks and blowing snow. Moreover, the external design appearance of the roof will not suffer at all, the sealants are applied under the roofing materials and are completely invisible from the outside.
	These are places with an increased likelihood of leaks. The fact is that most often structures are adjoined from various building materials. And they have very unequal coefficients of thermal expansion, linear changes appear during operation, the nodes constantly change their sizes. The sealant must not only ensure complete tightness, but also damp the vibrations of the architectural elements.
	Leaks occur due to mechanical damage or physical aging of roofing materials, natural disasters or gross violation of the recommended laying technology. Their consequences can be very unpleasant, especially for insulated roofing systems. Water lingers in the glass wool for a long time; it can be noticed on the inner surface of the attic rooms after a few years. All this time, the wooden structures of the truss system are operated in conditions of high humidity, which has an extremely negative effect on their condition. It is very time-consuming, difficult and expensive to overhaul the roof. In some cases, the cost of repair and liquidation of the consequences of wetting significantly exceeds the price of new construction. Modern high-quality sealants make it possible to quickly and reliably seal leaks. Such patches, depending on the location and type of roofing materials, can last for several years. During this time, the developer will plan his further actions without haste, save money for expensive repairs, provide himself with temporary housing, etc.

The industry produces several types of sealants, differing in chemical composition and physical parameters. Each type has its own line, but the differences between these products are no longer so noticeable.

Tape sealants

They are very convenient to use, widely used for finishing the junction points, during the assembly of metal ventilation systems and chimneys. In most cases, they have a bitumen base, innovative additives are added to the traditional material that increase adhesion with various building materials. The outer surface of the tape sealants is protected by a layer of foil, which prevents the negative effects of harsh ultraviolet rays.

Advantages of tape sealants:

• high resistance to the negative influence of atmospheric factors;
• ease of use;
• versatility of application;
• duration of operation;
• the relative cheapness of repair work.

Prices for sealed tapes

Sealant tape

Bituminous sealants in plastic tubes

They are used to seal small seams and junctions, come in convenient packaging, and can be stored for a long period of time. Such sealants can eliminate detected leaks or increase the reliability of some problem areas of the roof even at the stage of its installation. Disadvantages - high toxicity and low resistance to critical temperatures. Such a sealant reacts equally negatively to excessive heating or cooling.

Advantages of bituminous sealants:

• the highest indicators of moisture resistance;
• excellent adhesion parameters with all building materials;
• compact packaging allows you to work in very inconvenient places;
• various color shades.

This is a very well-known material that has been used for a long time and is well known to all professional roofers. One of the cheapest in terms of cost.

Rubber sealants

The main substance is the so-called artificial rubber. A rather complex material in terms of chemical composition. Has high values ​​of plasticity, can easily compensate for significant temperature fluctuations of adjacent architectural structures. Universal use, disadvantage - it is not recommended to apply to completely open roof areas.

Silicone sealants

They have many varieties, they are sold both in tubes for a pistol and in containers. The second option is for industrial use, rarely used in individual construction. Most often they are used as an additional layer of roof waterproofing, the upper surface of the sealant is protected from direct sunlight.

Acrylic sealants

In terms of performance, they are similar to silicone ones, but they are somewhat cheaper. Disadvantages - they require very careful preparation of surfaces, at the slightest violation of this requirement, the adhesion indicators are critically reduced, after a few weeks lamination is possible. For all operational parameters, they are inferior to the above-described compositions. Advantages - completely odorless, water-based, according to sanitary requirements, there are no restrictions on use. It is advisable to use it as a temporary remedy during the elimination of large leaks.

Polyurethane

Modern materials with excellent performance characteristics. An important advantage - after hardening, the surface is durable and is not afraid of dynamic and static loads. In terms of cost, they are classified as expensive, but the price is fully paid off by excellent quality. It is easy to work with them, the requirements for surface cleanliness are not as strict as for acrylic ones. The materials are universal in use, it is allowed to repair any type of roofing.

Polyurethane sealant prices

Polyurethane sealant

Two-component

Some of the most expensive and high quality sealants are made from silicone and synthetic rubber. They require great care during work. Violations of the proportions and technologies recommended by the manufacturers inevitably impair the reliability of the seal. After mixing the compositions, the application time is limited, the sealant that begins to harden is unsuitable for further use. It is prohibited to breed again. The fact is that hardening occurs as a result of chemical reactions, it is impossible to stop them.

Two-component sealants retain their properties over a wide temperature range, some of the most expensive types can work at -50 ° C. Such performance characteristics make it possible to use two-component sealants in the regions of the Far North.

Roof sealing mastics

Cheaper materials are most often included in the technology of laying roll coverings. With their help, the backing layer is glued to the base. At the same time, mastics penetrate into concrete or cement-sand screed and serve as additional waterproofing. Modern mastics can be considered reliable and durable sealants.

How to choose the right sealant

Despite the fact that many compositions are considered universal, their adhesion indicators to various materials are not the same. Two more significant differences are plasticity and resistance to harsh ultraviolet rays. Some sealants adhere well to smooth metal surfaces, others to rough surfaces.

Plasticity is of great importance. If it is necessary to seal an area with significant linear vibrations, then appropriate materials should be selected. If the sealant is tough, then it will inevitably crack with all the negative consequences.

Another criterion that is recommended to pay attention to is the price. There is no universal advice here, the decision must be made independently, taking into account financial capabilities. To seal large volumes of surfaces, you can buy materials of a cheaper line; minor cracks are recommended to be sealed with expensive sealants.

The approximate cost of sealants

Actual prices cannot be named due to constant fluctuations.

Here is a list of materials with an approximate cost as it increases:

• silicone ≈85 rubles;
• bituminous ≈ 90 rubles;
• acrylic ≈100 rubles;
• two-component ≈130 rubles;
• tape ≈140 rubles;
• polyurethane ≈160 rubles.

This is a conventional scale, in each group there are more expensive, significant fluctuations. It must be remembered that a high price does not always correspond to the same high quality. Well-known companies sometimes deliberately inflate prices and force customers to pay for brands. In this way, they are trying to offset the costs of their own sealant development and, of course, increase the profitability of production.

The sealant has special reinforcing fibers, which increases the strength. The material is transparent, completely invisible on the roofs, it has good adhesion rates with all types of roofing.

Important. The composition must be applied to previously cleaned surfaces. The layer thickness should not exceed 5mm.

It is a new and innovative material, one of the few that can be used on wet roofs or underwater. Sealing occurs instantly immediately after its contact with the treated surfaces.

1. Sealing seam roofing sheets. At a distance of about 1 cm from the edge of the sheet metal, apply a strip of the composition with a thickness of ≈ 3–5 mm. Press the elements firmly and leave them in this position until they solidify completely.

   

2. It is recommended to seal the gutter joints, especially if they are installed with a slight slope. Permitted to use when connecting pipes with water receivers. Any excess material that has protruded should be removed immediately, leveled with your fingers or rubber spatulas. If this is not done, then after hardening, a bump will form, which will obstruct the flow of water along the gutters.

   

3. During the installation of metal sills on parapets, sealants must be applied in the gap between the brickwork... Immediately insert the used protective metal strip and fix its position in an accessible way. Fill the gap in the upper part with additional material. It must be stuffed to the full depth, the excess is removed.

   The process of sealing cracks in a shingle roof

Manufacturers allow the use of sealant at temperatures from + 40 ° C to -10 ° C, but experienced builders advise not to seal leaks at sub-zero temperatures. Practice has shown that negative temperatures have a negative impact on the adhesion parameters.

Sealant gun prices

Sealant gun

Video - How to use a rubber sealant

The modern construction industry produces a wide range of roof sealants. They have different physical and operational characteristics, which greatly expands the scope of their use. How to choose a sealant for sealing the abutment of vertical structures

Sealants are made on the basis of modified bitumen, polymers or oligomers. Oligomers are a relatively new product, unlike polymers, they consist of a long chain of molecules with the same constituent units. In polymers, the number of molecular units is practically unlimited; each is assembled from several chemical elements. During curing, materials react with oxygen and steam to form a durable coating that is inaccessible to water.

Currently, the construction industry offers builders sealants based on acrylic, butyl rubber, polyurethane and silicone. Each of them has its own performance indicators, there are strengths and weaknesses. When choosing a specific sealant, it is necessary to take into account not only the physical parameters of the composition, but also the specific place of its use.

Silicone sealants

The most common and versatile formulations are one-component sealants. They are easy to use and have a long service life. After solidification, a dense but plastic layer forms. The sealant is completely sealed for water and can compensate for relatively large variations in linear dimensions. This quality is very important for finishing metal roofs that have high coefficients of thermal expansion. In summer, the metal heats up, which causes a decrease in the size of the sealed gaps; in winter, the opposite effect is observed. The silicone sealant compensates for these fluctuations without losing the original properties.

The advantages of silicone sealants.

1. High adhesion rates with most building materials. The only condition is that the surfaces must be clean and free from grease.
2. Elasticity. After hardening, the sealant resembles rubber, under load it is strongly compressed, after removing the forces it returns to its original shape. At the same time, it does not peel off from the surfaces to be joined.
3. Manufacturability. You can continue installation work on laying the roofing elements immediately after applying the sealant. This property speeds up the process of installing metal roofing on the most difficult roof areas.
4. Not afraid of sudden temperature changes within wide limits. A very important quality for all roofing materials, including sealants.

Roofing silicone sealant "Megasil"

The weaknesses include insufficient adhesion to metal profiles coated with polymer dyes. Silicone reacts rather negatively to ultraviolet radiation; it is recommended to use it in places protected from the sun. And the last drawback - silicone sealants cannot be painted, they always remain visible on the roof.

Prices for silicone sealants

Silicone sealant

Polysulfide sealants

These are the so-called thiokol compositions, made on the basis of modified bitumen. A very well-known type of roof sealant for universal use. Service life is not less than 15 years, can be operated within the range from -40 ° С to + 140 ° С. It is recommended to apply not in one thick layer, but in several thin ones. This is due to the fact that oxygen and water vapor are needed for its hardening, and they cannot quickly penetrate into a thick layer to the entire depth.

Disadvantages.

1. A long process of polymerization, complete hardening, depending on the thickness of the applied layer, lasts 2-4 days. In this regard, it is recommended to apply it at the finishing stages of roofing works.
2. Lack of elasticity. In terms of hardness, it resembles cold natural bitumen, which does not allow the material to compensate for the linear vibrations of the roofing elements. With strong compression, microcracks appear, which subsequently expand and can cause loss of tightness.

For metal roofs, this composition is rarely used and only in those places where, for some reason, it is impossible to use other materials.

Polyurethane sealants

Material based on polyurethane foam, the best known is polyurethane foam. It has very high adhesion rates to all surfaces without exception, it is recommended to be applied to damp materials and in wet weather. If climatic conditions become desperate, then the surfaces should be moistened with a sprinkler. After applying the foam, it also needs to be moistened. The sealant is used to seal large gaps, often as a repair compound.

It has two significant drawbacks.

1. Polyurethane reacts very negatively to harsh UV radiation. The foam quickly loses its plasticity, crumbles, turns into a fine powder. Apply sealant only in places inaccessible to sunlight.
2. For some unknown reason, birds fell in love with polyurethane foam. As soon as they find it, whole flocks flock and within a few days there will be no trace of the sealing.

Two-component polyurethane-based sealants do not have such disadvantages. But they are difficult to use, very expensive, and release toxic substances into the air. The advantages of two-component compositions include high operational parameters, maximum adhesion, almost completely eliminating the likelihood of delamination and resistance to UV rays.

Polyurethane sealant prices

Polyurethane sealant

Acrylic sealants

Belongs to the class of budget materials for sealing metal roofs. For outdoor roofing works, special types are produced with increased parameters of resistance to atmospheric precipitation, sunlight and temperature fluctuations. The surface of the hardened sealant can be easily painted with any compounds, it is not afraid of the effects of aggressive chemical compounds. It is one of the best sealants for use in urban environments where there are high concentrations of smog in the air. The disadvantage is the complete lack of plasticity, due to constantly changing cyclic loads, acrylic begins to crumble.

Sealant "Accent-117"

Recently, an acrylic siliconized sealant has appeared in the implementation, which has retained all the existing advantages and is devoid of the main disadvantages. Except for one thing - the composition reacts negatively to ultraviolet radiation, it can only be used in protected places.

This is not a traditional tube-like sealant, but an aluminum tape coated with a special sealant on one surface. It is very convenient to use, it is used to seal various units. And not only with a rectilinear shape, but also with a complex geometry. Butyl rubber is reliably protected from exposure to ultraviolet rays by a metal tape, such a coating greatly increases the life of the sealant. The tape does not lose its original properties at temperatures of -60 ° C ... + 90 ° C, has excellent adhesion values ​​to all clean and grease-free surfaces.

It is used for reliable sealing of metal profile joints on roofs with a low angle of inclination, can be used on chimneys, when sealing relatively large gaps. An excellent option for self-sealing of exit points on the roof of utilities. Butyl rubber is also sold in liquid form, it is used as a base for laying the next layers of waterproofing or for sealing small gaps.

Prices for butyl rubber tapes

In what nodes of the roofing from corrugated board are sealants used

The more complex the structure of the rafter system, the more places in it with increased risks of leaks. Which areas should be treated with sealants?

Endows

Components that are very complex from a technological point of view. In these places, the side surfaces of the slopes converge at different angles. The valley passes a large amount of water, withstands the highest loads from the snow cover. And all this despite the fact that the metal sheets are cut, water can get under the individual elements.

At small angles of inclination of the roof, professionals recommend sealing the overlap between the planks of the lower valley with a sealant. It is she who diverts the water coming from the slopes into the drain systems. If mistakes were made during the installation of this element, then during operation the strips bend, water can get under the metal.

Leaks in valleys are very dangerous for several reasons.

1. Firstly, it is difficult to notice them in time from the attic, especially if it is converted into a residential attic. Leaks are only visible when water comes through on the exterior wall cladding. Until that moment, quite a long time can pass, the wet wooden structures of the truss system will lose their original bearing capacity. As a result, very complex and very expensive repairs will have to be done.
2. Secondly, the valleys are structurally located in hard-to-reach places of the roofing system. You can only see the problem after a very thorough and professional inspection of the attic space. Ordinary residents who do not have a lot of construction experience are not able to fulfill such a complex professional task.
3. Thirdly, in the valleys there are no supporting rafter legs, the structure is fixed only to the crate. And its strength is not enough; under the influence of statistical and dynamic loads, the geometry may slightly change. As a result, the elements of the valley are loosened, and the likelihood of depressurization increases.

Places of exits of chimneys, ventilation pipes and other engineering structures

Most often, standard pass-throughs are installed here, but in some cases, the roofing master must completely perform the sealing. The composition must be carefully processed around the perimeter of all penetrations, it is the sealant that guarantees the absence of leaks and the reliability of the roof.

Drainage systems

They are installed on any type of roofing, but they all have the same requirements - functionality and durability. To achieve maximum tightness of the joints of the gutters and plugs, all equipment manufacturers strongly recommend that they be coated with a high-quality sealant. Particular attention should be paid to metal drainage systems.

Sealant gun prices

Sealant gun

Nodes of abutment to vertical walls

These can be brick chimneys, vertical walls, etc. In these places, the likelihood of leakage is as great as in the valleys. The adjoining is done using a special technology with chipping or filing brick surfaces. But always, to increase reliability, you need to additionally finish the joints with roofing sealants.

Video - How to bypass the chimney on the roof

Cornice knots

Sealants are used to fix the waterproof membrane. They firmly connect the waterproofing with the drip and exclude the ingress of water on the wooden elements. Another task of the sealants in these places is to guarantee to keep the membrane on the metal bar, not to allow strong gusts of wind to tear it off. The materials must maintain adhesion parameters at very high and low temperatures for the entire period of operation of the roof.

Places of joints of profiled sheets on roofs with an inclination of up to 12 °. Such roofs have a high chance of water inflow during oblique rain, in spring during uneven melting of snow. It freezes at night on the surface of the profiled sheets and does not allow water to leave in a timely manner during the day. As a result, the water level exceeds the profile height, leaks appear. It is necessary to seal both overlaps and lateral abutments.

Video - Eaves overhang. Common mistakes and how to do it right

Before making a final decision, it is recommended to consult with experienced roofers. They not only install new roofs, but also take part in the renovation of old ones. It is the repair work that allows you to see all the actual advantages and disadvantages of various types of sealants. It is not worth retiring only for advertising brochures, manufacturers often give one-sided and not completely honest information.

Pay attention to the actual performance, do not try to buy the cheapest sealants. The roof is a very important element of any structure. Its reliability determines not only the comfort of living, but also the duration of the operation of the entire building.

Video - Roofing Sealants

Profiled sheet with various (acrylic, polyester, etc.) polymer coatings has proven itself as a roofing material. Steel base and stiffening ribs guarantee long-term operation of corrugated roofs.

But, unfortunately, the bright prospects for trouble-free operation of the roof can collapse against the harsh reality. The reasons for such an unnecessary and untimely roof repair from a profiled sheet can be:

• Poorly made material~ in 5% of cases. An extremely rare moment and most often concerns the corrugated board, made in violation of technology and on handicraft equipment.
• Incorrect roof design~ 4%. Most often this is an insufficient slope angle or an incorrectly designed interface of hip and gable roofs.
• Disadvantages of the rafter system~ 12%. Unrestrained plane, subsidence of the crate during the operation of the building, insufficient treatment of the rafter system with antiseptics.
• Incorrect installation of the roof~ 79%. Moisture can leak out as a result of improper fastening of the sheet elements, but the main reason for the leakage of the roof from the corrugated board is the joints.

The joining of metal roofing elements from a profiled sheet can be divided into three groups:

Transverse joints of the profiled sheet on the roof

Transverse joints are the only group of mates that can be reduced in number to increase the reliability of the roof. It is important to note that the production of sheet metal sheeting with a length of 50 to 1200 centimeters is possible on the factory equipment. And if a supplier claims that the material is produced in a strictly defined size, then most likely it is an intermediary, not a manufacturer.

The use of profiled sheets of the required length (slope length + overhang value) allows you to completely avoid transverse joints. Sometimes such a process is impossible due to the difficulties of lifting and installation, which are too large in size for the metal elements of the roof.

If the roof is installed with transverse joints, a certain algorithm should be followed that connects the angle of inclination of the roof and the amount of overlap:

The reasons for moisture ingress under the roof plane can be three factors:

Longitudinal joints of corrugated roofing

Compliance with rather simple installation rules will allow you to avoid troubles such as penetrating spray of rain or snowflakes of a blizzard under the roof through the longitudinal joints.

• Firstly, the first row of sheets must be aligned with the lower edge using a cord stretched between the extreme points of the roof.
• Secondly, the extreme waves of the profiled sheets should coincide, forming a gap of no more than 1 - 2 mm.
• Thirdly. The joint of the sheet elements is fixed with roofing screws. The place of attachment is the ridge of the stiffener of the upper sheet. Mounting step no more than 400 mm. And with increased gaps from 150 mm.

If, nevertheless, the gaps of the joints have diverged, then you should use a sealant to seal them or fasten the side edges with a 4.2 x 25 mm press washer with a drill and a washer with a rubber gasket.

Pairing sheets of corrugated board with additional elements

The joint of the corrugated board with the ridge strip is the most difficult element of outdoor roofing work. It is important that the skates are attached not only to the metal of the profiled sheets, but also to the wooden base of the rafter system. Fastening is carried out with roofing screws into the ridge of the stiffener, through the side of the ridge. Fasteners are carried out in each wave.

The distance between the upper cuts of the joined sheets should not exceed 50 mm.

Even with a perfect fit of the ridge, there will be gaps between the crests of the waves between it and the corrugated board. Rain is unlikely to penetrate such gaps, but snow will easily fall into the under-roof space. Even with a small height of the stiffeners, it is not economically feasible to fill the voids with sealant alone. The basis for the application of silicone can serve as pieces of extruded polystyrene foam or polyurethane foam filling the cavities between the ridge and the sheet. But liquid polyurethane (polyurethane foam) must be used with extreme caution in order to avoid violating the integrity of the roof.

The valley strips are connected to the corrugated board in the following sequence:

1. Fastening the lower plank to the lathing with a 4.2 x 25 mm press washer with a drill and a washer with a rubber gasket. How this is done can be seen in the video:
   
2. Installation of corrugated board.
3. Installation of the upper (decorative) valley is carried out with roofing screws.
4. Sealing the joints of the sheets and the upper valley with polyurethane foam and sealant.

Wall extensions protect the roof from moisture penetration between the wall and the profiled sheets.

Metal parts are connected with roofing screws. Such strips are attached to the wall with dowels (brick) or a press washer with a rubber gasket. The joints between the wall and the wall strip are sealed with tape sealants. The joints between sheets and extrusions are treated with rubber or silicone sealants.

Installation of the front and wind strips is carried out directly on the sheets of corrugated board with roofing screws and does not require sealing.

Sergey Novozhilov is an expert in roofing materials with 9 years of practical experience in the field of engineering solutions in construction.

Most of the problems with metal roofing are caused by the loss of sealing of the connecting joints between the individual parts of the installation. As a result, atmospheric moisture begins to enter the building, causing very unpleasant consequences, up to the failure of the enclosing and rafter structures.

What are roofing sealants?

To increase the reliability and strength of the roofing, you can use special sealants for metal roofing, which are characterized by the following characteristics:

• High elasticity.
• Good adhesion to metal surfaces.
• Vibration resistance.
• Ability to resist moisture for a long time.
• Inertness to atmospheric influences.

By the type of reaching a working condition, metal roof sealants are non-curing and curing:

1. Uncured... Demonstrate stability of initial performance after use. They are used as seals for joints of various shapes. The non-curing sealant for galvanized roofing is characterized by good adhesion and resistance to weathering. The material is able to maintain its performance at temperatures from -60 to +140 degrees. It is produced in the form of a packaged paste or double-sided sealing tape, convenient for sealing various folded joints.
2. Curable... In the course of drying or chemical reaction, the initial characteristics of the composition change. In this case, mixing of separately stored components will be required immediately before use.

Regardless of the mixing method (manual or mechanical), it is necessary to use the finished material within three hours.

Finding the right roof sealant is both simple and complex. In the case of using low-quality products, the consequences for the building will be the most sad, therefore it is best to give preference to products from well-known manufacturers.

Among them are:

• "Titanium"... The composition can be used in frosty weather, while the type of roofing material does not matter. Due to its good adhesion, the composition fits equally well on both horizontal and vertical surfaces that do not require special preparation. Roofing glue sealant "Titan" is suitable for roofs made of metal, tiles, wood, etc. Tytan Industry PU-25 was developed especially for flat and seam roofs.
• Sazilast 51 - 53... A good option for a folded roof. Insulation can be carried out at a temperature of -15 - +40 degrees.
• SOUDAL Aquafix... A universal seal that fits well on almost any roofing material. This sealant will work even on damp and underwater surfaces. An excellent option when you need to carry out work very quickly or in the course of precipitation. With its help, mainly metal tiles and gutters are repaired. The surface to be treated must be pre-degreased and free of contamination.
• Ceresit... Silicone compound with exceptional resistance to abnormal temperatures. When hardened, it takes the form of plastic. The lack of elasticity of silicone for the roof prevents it from deforming along with the seam, therefore it is better not to use it on movable roofs.

How to use silicone on the roof

Silicone sealants are currently the most popular. In operation, it is very simple, so the help of professionals in this case is not needed. To achieve a good seal quality, some guidelines will need to be followed. So, the depth and width of the processed seam should have an optimal ratio of 2/3. In practice, the depth exceeds the recommended value: this problem is solved by pre-laying a special polyethylene cord. For its manufacture, ordinary plastic bags will fit.

To fix significant widths, you can also use polyethylene cut into strips. Before installing roof silicone, the joint surface must be thoroughly cleaned and degreased. Some situations will require preliminary priming. To obtain a flat surface, use a trowel of suitable width, specially designed for such operations. Alternatively, you can apply a leveling spray. The drying rate of the silicone sealant is influenced by the depth of application, but the initial setting of the paste is quite fast.

How galvanized seam roofing is sealed

For sealing seams and joints of seam fasteners, it is better to use a bitumen or polyurethane seam sealant for seam roofing. In this case, the silicone composition is not suitable, since it provokes the appearance of rust on the folds. The procedure for sealing a folded roof is carried out in several stages. The first step is to clean the surface, removing not only dirt, but also rust. Further, degreasing is carried out using a solvent. When the folds are well dry, paste can be applied to them, observing the recommended operating temperature.

This type of sealant is not always convenient: this applies to situations where the paste must lie flush with the surface, without forming a bulge. Therefore, self-adhesive sealing tapes are often used on corrugated roofs. One of its sides will require cleaning from the release layer. Next, the sticky part is pressed onto a cleaned and degreased joint. To improve joining, the edge of the tape is usually rolled with a roller to avoid scuffing during operation. Such difficult areas as the junction to the structures overlooking the roof are processed with special corrugated tapes.