The main details (nodes) of a roofing carpet made of flexible tiles include a cornice, a ridge, a ridge, a valley and its adjoining to a wall, a pipe, and ventilation elements.

Figure 4.1. Roofshield shingle marking scheme
1 - wall of the adjoining building; 2 - safety pipe; 3 - elevator shaft; 4 - skate; 5 - valley.

Nodes 1.1 and 1.2. Roofshield bituminous roofing on the roof eaves of the attic floor (a) and the cold attic (b)
1 - flexible tiles; 2 - lining layer; 3 - solid flooring; 4 - filly; 5 - windproof diffuse waterproofing film; 6 - crate; 7 - Mauerlat; 8 - rafter; 9 - ventilation gap; 10 - thermal insulation; 11 - vapor barrier; 12 - drywall; 13 - anchor for fastening rafters and Mauerlat; 14 - frame of the cornice overhang; 15 - filing; 16 - drip; 17 - bars; 18 - cornice tiles; 19 - gutter bracket; 20 - carrier plate; 21 - waterproofing.

Node 1.3. Roofshield flexible tile on a warm covering cornice assembly above a log house wall
1 - flexible tiles; 2 - lining layer; 3 - solid flooring; 4 - filly; 5 - moisture resistant plywood; 6 - diffuse film type "Tyvek"; 7 - drywall sheet (2 layers); 7a - metal mesh made of wire Ø 2 mm or wire with a pitch of 250 mm; 7b - vapor barrier; 8 - crate; 9 - counter-brush; 9a - ventilated air gap; 10 - thermal insulation; 10a - rafter; 11 - cornice tiles; 12 - fastener; 13 - tray; 14 - drip; 15 - support board; 16 - wooden frame; 17 - gluing vapor barrier; 18 - filing the cornice.

Nodes 2.1 and 2.2. Roofshield flexible tiles on the ridge assembly of the roof of the attic floor with ventilation through viewing and gable windows (a) and through a ridge deflector (b)
1 - flexible tiles; 2 - lining layer; 3 - flooring; 4 - rafter; 5 - windproof diffusion-waterproofing film; 6 - counter-lattice; 7 - puff; 8 - gable window; 9 - ventilation gap; 10 - thermal insulation; 11 - vapor barrier; 12 - drywall; 13 - bars; 14 - ridge tiles; 15 - ridge deflector; 16 - crate; 17 - ventilation flows; 18 - sealant.

Nodes 2.3 and 2.4. Bituminous tiles on a ridge unit with ventilation through a solid ridge aerator (a) and through a roof fan (b)
one - ; 2 - wooden block (60x49 mm); 3 - drywall sheet (2 layers); 4 - thermal insulation; 5 - ventilation hole; 6 - lining layer; 7 - solid ridge aerator; 8 - counter-lattice; 9 - roofing carpet; 10 - windproof diffusion film; 11 - roof fan; 12 - rafter; 13 - gable window; 14 - solid flooring; 15 - puff.

Nodes 2.5 and 3. Flexible tiles on the ridge node (a) and the ridge (b) of the cold attic
1 - rafter; 2 - crate; 3 - fastener (nails); 4 - solid flooring from edged boards; 5 - roofing carpet on the ventilation system; 6 - wooden beam 70x50x150 mm (step 600 mm); 7 - galvanized metal mesh; 8 - flexible tiles; 9 - solid plywood flooring; 10 - counter-lattice; 11 - waterproofing film; 12 - board; 13 - spinal rafter leg; 14 - lining layer.

Nodes 4.1 and 4.2. Endova cold (a) attic and attic (b)
1 - rafter; 2 - valley carpet; 3 - flexible tiles; 4 - solid plywood flooring; 5 - counter-lattice; 6 - waterproofing film; 7 - crate; 8 - board; 9 - valley leg; 10 - drywall sheet (2 layers); 11 - vapor barrier; 12 - thermal insulation; 13 - ventilated air gap; 14 - ventilation hole (step 500 mm); 15 - wooden block.

Node 5
1 - end wall of the elevator shaft; 2 - gluing a waterproofing film; 3 - fine; 4 - sealant; 5 - apron made of galvanized roofing steel; 6 - metal bar; 7 - fastener; 8 - wooden beam (50x50 mm); 9 - additional roofing carpet; 10 - flexible tiles; 11 - solid plywood flooring; 12 - counter-lattice; 13 - waterproofing film; 14 - board; 15 - crate; 16 - rafter.

Node 6
1 - rafter; 2 - crate; 3 - bar; 4 - waterproofing film; 5 - counter-lattice; 6 - solid flooring from edged boards; 7 - flexible tiles; 8 - sealant; 9 - lining layer; 10 - wooden rail; 10a - additional carpet made of rolled material; 11 - apron made of galvanized steel; 12 - fastener; 13 - metal bar; 14 - fine; 15 - gluing; 16 - wall.

Node 7. Fastening the safety pipe
Node 8. Guardrail fastening
1 - counter-lattice; 2 - plywood flooring; 3 - roofing from flexible tiles; 4 - sealant; 5 - earring h = 10 mm, step - 1200 mm; 6 - screw; 7 - plate 120x70x6 mm; 8 - welding; 9 - safety pipe O 50x50 mm; 10 - corner 50; 11 - a lattice of rods O 10 mm through 100 mm; 12 - brace (plate 40x4 mm); 13 - stand - pipe O 50 mm; 14 - plate 40x4 mm; 15 - waterproofing film; 16 - board; 17 - crate; 18 - rafter (Mauerlat).

Node 9
1 - chimney; 2 - drywall; 3 - wooden block 50x50 mm; 4 - sealant; 5 - collar; 6 - additional carpet; 7 - deflector; 8 - roofing from flexible tiles.

Node 10. Adjoining the roof to a brick pipe
1 - chimney; 2 - drywall; 3 - vapor barrier; 4 - thermal insulation; 5 - flooring; 6 - flexible tiles; 7 - rolled material; 8 - rear corner; 9 - metal bar; 10 - sealant; 11 - front corner; 12 - side corner; 13 - rafter; 14 - fastener; 15 - ventilation channel.

Node 11
1 - flexible tiles; 2 - mastic-sealant; 3 - lining material; 4 - the upper section of the salary; 5 - the lower section of the salary; 6 - ventilation channel; 7 - vapor barrier; 8 - thermal insulation (); 9 - drywall; 10 - reinforced concrete structure.

When thinking about building their own home, developers are often quite lenient on a flat roof. Even in comparison with a lean-to, not to mention a gable, and even more so a multi-pitched roof, it seems too “simple”.

But professionals know that it is not the architectural element or building materials that matter, but how they fit into the architect's plan. A house with a flat roof can look no less elegant than with any other device!

Flat roof device

Especially among the undeniable advantages of a flat (soft) roof:

• Relatively low cost and available materials;
• Ease of laying roofing;
• The ability to fully use the space under the roof and the roof itself;
• Safety in operation;
• Unlike roofing, which uses other materials, flat roofing can be installed in the cold season using special technologies.

Flat roof types

Soft roofing can be of two types: unexploited and exploited. The first is an ordinary flat roof (for example, a multi-storey building), on which only builders climb for its repair and maintenance.

Operated roofs are used in industrial or civil buildings and structures where permanent or regular access of people to the roof is provided (observation platforms, solarium, etc.), placement of heavy equipment or objects, outdoor and winter gardens, arrangement of parking for cars, helipad etc.

Design features

In contrast to pitched roofs, flat roofs do not use roofing pieces and sheet materials. The second name for this type of roofing - soft roofing - was given just by those types of insulating coatings that provide for their laying with a continuous carpet: bitumen, polymer, bitumen-polymer. The roof must be elastic so as not to deform under the influence of temperature changes, under the influence of moisture and mechanical deformations of the base.

All these properties are possessed by a membrane flat roof, which is a kind of multi-layered “pie” of layers of heat-vapor and waterproofing, laid on a prefabricated or monolithic reinforced concrete slab, metal corrugated board and sometimes on a wooden base.

flat roof pie

Depending on the purpose of the roof and the materials used, the roofing cake is different. For example, when laying an exploitable roof on a reinforced concrete slab, it can consist of many layers, for example:

• Roofing technoelast layer;
• Leveling screed from DSP;
• Vapor barrier layer;
• Thermal insulation layer (extruded polystyrene foam);
• Two layers of waterproofing;
• Leveling reinforced screed from DSP;
• Polyethylene film;
• Expanded clay layer (on a slope);
• Glass insulation layer;
• Reinforced concrete slab.

In such cases, fastening has to be done not through the entire roof, but by connecting the screeds and the layers of insulation lying above them.

When installing a non-exploited roofing, the number of upper layers will be less, however, the principle of the roof and the materials used remain unchanged: base - vapor barrier - insulation (mineral wool slabs) - waterproofing from roofing roll materials.

Since the upper waterproofing layer is exposed to aggressive environmental influences (temperature changes, moisture, wind), and if it is damaged, the entire roof suffers, experts have developed an inversion, that is, the reverse order of layer placement: base - waterproofing - thermal insulation - protective material (for example, the so-called geotextile). At the top, the roof can be filled with monolithic concrete.

What are "roof nodes"?

Flat roof nodes are all joints of the roof structure: connecting corners, places where the roofing adjoins the walls (parapet) of the building or encircles chimneys, ventilation pipes, lightning rods, etc., mates with external drains.

In such places, installation is done very carefully and carefully - if the tightness of the joints is broken, moisture penetrates inside. Therefore, roof units are usually waterproofed additionally (for example, using bituminous mastic).

Most often, leaks and destruction occur in the area where a flat roof adjoins a wall. It is this node that requires special attention - both in its design, and in the construction of the roof, and during the operation of the roof. When the tightness of the joint is broken, then even if water does not flow along the walls after rain or during a thaw, fungus or mold often appear on them.

The tightness of joints and nodes is achieved due to strict adherence to technology, as well as through the use of special sealants, auxiliary materials and components (building parts) are also used: they allow the roof to provide the necessary operational parameters, and therefore reliably protect the building from the vagaries of the weather.

Mounting points

The main layers of a flat roof

An approximate diagram of the attachment point of a flat roof to the base can be as follows:

• Roofing technoelast layer;
• Lining technoelast layer;
• The top layer of insulation;
• The bottom layer of insulation;
• Vapor barrier layer;
• Concrete base or base made of metal corrugated board.

For fastening, a roofing dish-shaped “fungus” dowel with a diameter of 20 to 190 millimeters and a long screw (FBD; FBS) or a concrete screw is used. The length of the dowel is taken 10-20% less than the thickness of the roofing. The screw must enter the corrugated sheet or concrete base by at least 20 millimeters, and the coating must be fixed only to the crest of the wave of the corrugated sheet.

When carrying out work, you must adhere to certain rules:

• The distance between the dowels must be< 20 см.
• When mounting a roofing cake to a profiled sheet or to wooden slabs, it is pierced with a dowel assembly with a self-tapping screw. In a concrete base, you need to pre-drill a mounting hole for a dowel or screw on concrete.
• The mounted dowel must fit snugly against the surface to be attached.

The coating is mounted to the base through its penultimate layer using a screwdriver without impact loads (rotational speed - 1500-2000 rpm). After fastening, the final layer of the coating is welded, which covers the dowel head.

Junction nodes

Roof device

Areas where the roof adjoins walls, chimneys, etc. require particularly careful isolation.

At the junctions of the roof to the walls, transitional sides are equipped and the roofing carpet is attached to the base in the same way as described above. For concrete and reinforced concrete bases, both mechanical fastening with screws and fusing (gluing) of the insulating layer can be used, or for reliability, combine these methods.

To seal the joints, a special universal polyurethane mastic is used. After application, it hardens under the influence of air, turning into an elastic rubber-like waterproof mass.

Unlike some other sealants, its volume does not change. You can use this mastic for all types of flat roofs. It is applied with a brush or paint roller in two layers, the colors of which are different, and this makes it possible to control the thickness of the layer and its uniformity. In addition, it adheres perfectly to all surfaces and is resistant to direct sunlight.

In addition to mastic, pastes based on bitumen, lime and special plastic clay are used to seal joints.

Auxiliary parts for roof units

Roof waterproofing

Since embedding chimneys, ventilation pipes and other parts into a flat roof is a responsible process, special materials and parts are used for the installation of soft roof units. For example, this is a special polymer (butyl) tape with aluminum coating. It is easy to stick on any base, and the gaps are sealed with polymer sealant or mastic.

Profiled sheet (profiles) has proven itself in the best way as a material for roofing because of its functionality and low price. Thus, a roof made of profiled metal sheets is a fairly acceptable solution even for a beginner who decides to cope with this difficult task on his own. Profiled sheets are coatings that are sufficiently resistant to any mechanical and atmospheric influences, are quite practical, durable and have an aesthetically pleasing appearance. Of course, the numerous advantages of the material in itself are not grounds for considering the issue of its mandatory use in roofing, however, it is impossible to find the best material for quick installation and long-term functioning of the roof. Moreover, even in order to properly prepare and strengthen the roofing units from a profiled sheet, too much special effort is not required. Taking into account the need to ensure a reliable connection between the components of this building material, it should be understood that special attention in this process should be given to roofing units made of corrugated board.

Features of a roof from a professional sheet

Before proceeding to cover the roof with this roofing material, one should consider its main characteristics and methods for organizing the adjoining of the roof. So, the main advantages of corrugated roofing are:

• high level of carrying capacity with a relatively small weight of the actual sheets;
• corrosion resistance;
• long service life of the coating;
• relatively simple installation of the main types of profiled sheets that are offered on the construction market.

Photo 1. Gable node.

They are sheets with a wave height of 8 to 44 mm, with a trapezoidal or sinusoidal profile shape. Lightweight profile sheets with a wave, 35 and 44 mm high are often used for roof construction. As a roofing material, a wall, frame profile is also actively used, the wave height of which varies from 57 to 114 mm, which adds additional rigidity to it.

Before proceeding with the laying of roofing sheets, builders should take care of acquiring the necessary tools for work:

• hacksaws;
• screwdrivers or drills with a hex head;
• screws or screws;
• material for waterproofing;
• directly professional sheet;
• preparation for work on the installation of corrugated roofing.

Before purchasing the necessary building material, experts advise preparing a site on which it will be possible to place the brought sheets.

After all, in no case should they be deformed. Otherwise, it will be almost impossible to achieve a reliable connection of the roof to the roof rafters. Think in advance about the process of feeding sheets to the roof, devices such as winches are most often used, or lumber rails can be installed. Most often, builders use logs.

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The main junctions of the material

Photo 2. Plank of the valley node.

The roofing material is laid on a truss system covered with a crate, which is created from bars with a section of 50x50 mm, with a pitch selected according to the dimensions of the profiled sheet used. Roof insulation is usually carried out using thermal profiles and a gasket made of thermal insulation materials. Roof waterproofing will require waterproof coatings, such as special membranes or hydrophobic films.

When laying the roof, special attention should be paid to places where several sheets are joined or to those sections of the roof where it adjoins the wall of the building. These points are called nodes, and if they are carelessly treated during installation, then in the future, such roofs are unlikely to reliably protect the building and the people living or simply staying in it from adverse external influences. The sheets themselves are very easy to fit, because they are light in weight and do not require special skills from builders. But the nodes of the roof made of galvanized iron are a rather difficult moment. Therefore, although roofing work is fast, joints take the most time.

It is especially important to correctly cope with the transition points of the sheet material of the roof from the horizontal to the vertical plane. This node is carried out according to the following scenario: a bar is installed at the junction, which will protect the roof from moisture and dust getting inside, before that, a sealant is installed under the bar. At the level where the bar adjoins the wall, in which it will be necessary to make a strobe and install it in the groove. Then, with the help of dowels, attach the bar and seal all the junctions with sealant. It is advised to connect the bar with the profile using self-tapping screws, which are screwed into the most protruding point of the wave.

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The main components of the profiled sheet and the materials necessary for their proper processing

Photo 3. Scheme of the wall.

There are several types of roofing nodes. These are gable, and valley, and eaves, and ridge knots. Plus, the junction to the wall.

The front knot (photo No. 1) is arranged using the following tools and materials:

1. Professional sheets.
2. Screws - self-tapping roofing screws.
3. Front plate.
4. Waterproof film.
5. Wind board.

The key elements of the pediment are mounted on a wooden frame, which must be treated with an antiseptic solution without fail. Then lay the waterproofing layer, which is necessary to ensure ventilation and protect the frame from condensation. A layer of insulation is laid on top of the waterproofing layer. Then proceed to sheathing the frame with bars. They need to be installed in increments of up to 40 cm. And only after that the entire gable can be covered with corrugated board. Fix the sheets with self-tapping screws, which should be screwed into the deflection of the sheet using an electric drill. Between themselves, the sheets are fastened with self-tapping screws with rivets.

Photo 4. Proper organization of the ridge knot.

Under the bar of the valley node (photo No. 2), a dense flooring is made of edged boards, at the level of the existing crate, stepping back a distance of 60 cm from both sides of the groove. Then install the bottom planks of the valley, overlapping at least 20 cm. Attach the lower bar first from the edges with nails, and complete reinforcement must be done simultaneously with the final installation of the entire roof.

High-quality device of the ridge knot.

One of the most difficult and important moments of covering a gable roof is the correct organization of the ridge assembly (photo No. 4). At the same time, the ridge strips should be laid so that the overlap is at least 10 cm. The profiled sheets are fastened to the crate with roofing screws, which are recommended to be installed after approximately 30 cm.

Installing the junction bar.

The length of the junction bar is most often 2 meters. Lay these planks with an overlap of 20 cm. In those places where the plank will join the profile sheets, it should be reinforced with self-tapping screws. A suitable step should be 40 cm. The area where this plank is attached to the wall can be hidden under the decorative trim.

The roof system is one of the most important building systems. Each element of a flat or pitched roof, even if it seems minor, has its own purpose, and contributes to the coordinated work of the roof structure as a whole.

An extremely important role in ensuring the reliability and functionality of the roof is played by typical roof units, which are associated with the junction of slopes, parapets, various technological communications, etc. The quality of the roof units requires special attention, since they are considered the most vulnerable to atmospheric influences that destroy over time, roofing and waterproofing.

Let us dwell separately on some of the most important nodes on the roof.

Knot of the parapet of a flat roof and adjoining to the walls

Structurally, for the connection to the wall, a steel apron or a special bar is installed. The vertical part of the latter is attached to the adjoining wall, and the horizontal part covers the roof.

The technology of the adjoining device for various roofing materials differs only in the way of sealing the seams, which inevitably appear during their installation. It is on the quality of this operation that the impenetrability of the roof depends to a greater extent.

Typical roof units can be made both with the device of an additional special niche in the wall, strobes, and without it. Sealants are used to seal seams. Today, bituminous compounds that were popular at one time have successfully replaced silicone ones.

• The nodes of the roof, covered with profiled metal, in the areas of junction with concrete or plastered brick walls, are performed as follows.

• When using a single steel apron, wall chasing will be required.
• A groove 2–3 cm deep is made at a height of 20 cm or more, parallel to the junction line.
• One of the edges of the apron, the upper one, is installed in a curtain, and the lower one is attracted to the roof. They are pre-treated with a sealant.
• Roofing self-tapping screws equipped with seals are used as fasteners. Neoprene or rubber, from which they are made, effectively protect the attachment points from moisture.
• The gate is then filled with a cement mortar.

If a special bar is used, then a wooden rail is fixed in the strobe.

• A vertical part of a protective bar made of profiled metal is attached to it.
• The other part of it lies on the surface of the roof.
• The strobe, as in the previous case, is filled with sealant or cement mortar.
• Manufacturers offer planks of various colors and, as a rule, there are no problems with choosing an additional element to match the color of the roof.

On a note

Waterproofing, if any, is brought under the bar and glued to the sealant, bituminous or silicone. The junction planks are joined along the length with an overlap of at least 10 cm.

An junction of this type can also be made using a double apron. Unlike the previous options, a strobe is not required here.

• Having fixed the upper apron to the wall, a lower apron is brought under it and coupled with the upper one.
• It is attached to the roofing with clamps.
• All connecting seams are treated with an appropriate sealant.

• For roofs made of natural tiles, the junction is performed using a special tape made of corrugated aluminum. It exactly repeats the profile of natural tiles. Docking seams are poured with hot bitumen, which reliably seals all joints, excluding moisture penetration.

On a note

Aluminum corrugated tape and mastic are also used for high-quality moisture protection of roof junctions covered with soft tiles.

• One of the simple and reliable technologies for making such a soft roof assembly is flashing. The essence of this method is to perform the following works:

• application of an elastic mastic with high hydrophobic characteristics;
• reinforcement of butt joints with a layer of geotextile;
• reapplying the layer.

Roof with parapet and its junctions

The design technology of the parapet assembly is practically the same. However, being unprotected, the design very soon becomes unusable. It is negatively affected by the influence of external factors - precipitation, sharp temperature fluctuations and more. Brick buildings are especially vulnerable in this sense. In other words, the parapet needs protection. For these purposes, a kind of steel visor is constructed above it, equipped with special droppers. It is through them that precipitation is removed. Moreover, the probability of hitting the parapet of water is negligible.

Connections to chimneys

Roof units of this type are characterized by the presence of high temperatures in the process of heating the chimney. That is why the tightness requirements for its construction are not enough, non-combustible materials are needed.

One of the options in demand today is a roof cut for a chimney, which can have a different shape, size and angle of inclination.

Another method of sealing is the use of a metal roofing apron of a special design, which allows you to protect the under-roof space from moisture penetration even in extreme conditions, for example, very heavy snowfalls or heavy rains accompanied by strong winds. If water nevertheless gets behind the apron, it will simply evaporate. Double aprons provide the best results.

Let's note some features of their installation to brick chimneys on metal roofs.

• Inner apron. This element ensures the tightness of the junction of the roofing with the chimney located above the slope. The installation is carried out before the installation of metal tiles in the chimney area.

• An apron made of steel profile is attached to the wall of the chimney and a mark is made along its upper edge. A groove is made on the wall along the resulting line, using a grinder for this.
• Work begins with the installation of an internal apron.
• After cleaning the groove, insert its lower element there and press it tightly, exactly aligning the upper part with the groove. They attach it to the wooden roof elements with self-tapping screws and seal it using a sealant. A flat sheet is brought under it, because of its shape it is called a tie, along which water should be drained, and directed towards the cornice or valley.
• Similarly, the elements of the apron are cut and installed on the sides and top, overlapping adjacent parts with an overlap of at least 15 cm.

• Outer apron. The installation of an external apron is started after laying the roofing material. Its installation does not differ from the installation of an internal apron, with the only difference being that the upper edge of the outer one is not recessed into the strobe. Instead, the joint is sealed using special sealants.

Joining roof slopes

The internal junctions of roof slopes, or, as they are called, valleys, are considered the most difficult nodes, from a technical point of view. They are typical for roofs that have a complex shape, such as, say, a hip hipped roof. These areas are the most dangerous in terms of the potential for leakage. A lot of various debris accumulating moisture, or ice, always accumulates here.

Methods for ensuring water tightness depend on the characteristics of the roof covering. The general principle of making nodes is to install elements of roofing iron under the cover, repeating the shape of the angle of connection of the slopes.

• For roofs made of metal, standard lower valleys are used. Their edges are bent so that water cannot get under the coating. Adjacencies are treated with a sealant or a self-adhesive porous sealant is used. The junction over the roofing is closed with decorative strips that match the color of the coating.
• To seal the roof nodes from flexible tiles, a continuous waterproofing carpet is laid on the valley.

Connection of technological passages of the roof

An excellent solution for these knots is Master Flash roofing. It is made of rubber, which is resistant to various influences, in particular, to temperature. The indisputable advantage of the Master Flash design is the ability to use it to seal a node of any diameter, even the place where a television cable passes. It is enough to choose a cutting slightly smaller than the diameter of the communication. The excess segment is cut off.

It is also important that this element, due to its elasticity, can be used for roofs with various profiles. For additional waterproofing of the assembly, silicone sealant is used.

On a note

Master Flash is available in a variety of colors to match the color of today's roofing materials.

At present, in connection with the emergence of not just new materials, but entire SYSTEMS of enclosing structures (consisting of dissimilar materials), great attention should be paid to understanding the physical processes occurring in the upper enclosing structures - roofs. Without this, their competent design and construction is impossible.

Rice. 1. External and internal factors affecting the roof

Roofs are subject to a range of forces that are closely related to processes both outside and inside the building (Fig. 1). Among these factors, in particular, include: precipitation; water vapor in the outdoor and indoor air of the building; wind; solar radiation; temperature fluctuations; chemically aggressive substances contained in the air, as well as some other components of the processes.

Influence of precipitation and wind

The wind with force throws water or snow onto the roof, which, with an insufficiently thought-out design of the roof and the roof as a whole or its individual components, can lead to leakage of the roof as a result of water or snow getting into the joints of the joining of roofing materials. In addition to rain, melting snow affects the roof. The most vulnerable places for leaks are the framing of chimneys and ventilation pipes and the abutment of the roof to various vertical surfaces: walls, gables, dormer windows.

The traditional technical solution for connecting roofs to walls and parapets, both frontal and lateral, provides for the manufacture of niches and gates in the walls (parapets) along the entire length of the connection and the installation of aprons made of galvanized roofing steel in them. It is allowed to install aprons from black roofing sheet, twice treated on both sides with hot drying oil and painted at least twice. Installing an apron without a niche or strobe by pressing it firmly against the wall does not provide a proper fit, and the assembly leaks. There are at least two reasons for this: firstly, the walls are not so even that it was possible to press the apron tightly against them; secondly, the sun will heat the apron and, due to thermal expansion, it will lengthen and bend between the fasteners away from the wall (Fig. 2).

rice. 2. Traditional solutions for joining roofs to walls and parapets

Mounting the upper part of the apron in a niche or gate eliminates this problem, here leaks are covered from above with wall material, which reliably closes them from rainwater, but does not protect them from snow. Therefore, when installing an apron in a niche, it is recommended to make the upper part at least 100 mm high, and when installed in a strobe, it is advisable to seal it with a cement-sand mortar. It is necessary to add right away that a simple sealing of a high niche with a solution is practically useless, the solution will crumble from there over time, winter frosts and wind will help, but it will still last 5–10 years. Protecting the apron with a solution will not allow the wind to blow snow into the strobe, where it will melt and melt water will flow under the iron. Aprons are fastened with nails to wooden antiseptic plugs, previously laid in the wall, for example, when erecting brickwork. The plug installation step is about 1 m. If wooden blocks of triangular section are attached to the plugs before installing the apron, then the plugs can be installed less often, and the edge of the apron will be pressed more tightly. Fastening the apron with a second triangular bar will make the knot almost waterproof. The strobe can be plastered and forgotten about until the iron of the apron rots.

Along the length, the elements of the aprons are overlapped in the direction of the water slope. The overlap is made at least 10 cm. If the aprons are joined not with an overlap, but with a lying fold, then the knot will turn out to be more reliable.

To protect the junction of the roof to the parapets, a “roof” made of roofing steel is installed on the latter, equipped with droppers (edges bent by a “hook”). A parapet apron with droppers released outside the walls protects the parapet from rain: water is drained from the walls through the droppers, drops come off and fall directly onto the roof or onto the apron of the junction. There is less water flowing directly down the walls. The parapet apron is fixed by pulling on T-shaped crutches, installed in increments of about 1 m and attached, in turn, with nails to wooden antiseptic plugs. In order to prevent the parapet apron from being torn off by a strong wind, its upper fastening with screws (self-tapping screws into a wooden cork) through the roofing sheet with the installation of rubber washers under the screw head is allowed.

Roof junctions to chimneys and ventilation shafts are solved in a similar way. Brick pipes are framed with aprons made of galvanized or treated black tin. The lower and side parts of the apron are laid on top of the roof, and the upper part is wound under it. From above, the aprons are covered with an overlap of brickwork. When making an apron, it is recommended to adhere to the dimensions shown in Fig. 3, they provide protection from melted snow. With heavy winter snowfalls, snow falls under the inside of the iron, the indicated dimensions of the apron will not allow melt water to penetrate under the roof. She, overcoming a long way, simply dries up.

rice. 3. Traditional solutions for pipe cutting units (dimensions in mm)

In pipes, especially smoke pipes, the installation of wooden plugs is unacceptable, therefore, the apron is fastened on recumbent folds, connecting all the roofing iron around the pipe into a single whole. If roofing is done around the ventilation shafts, then the apron can be nailed to wooden antiseptic plugs. Cutting around round, for example, asbestos-cement or PVC pipes, is clamped with another pipe of a larger diameter. The gap between the pipes is filled with molten bituminous mastic or some other sealant. A large gap, before pouring the sealant, is caulked with a fibrous material, for example, linen strands or rope, impregnated with oil paint or a bituminous primer. After caulking, the gap is filled with sealant or covered with a greasy cement-sand mortar.

When constructing roofs made of piece materials, for example, slate, ondulin and the like, the amount of lateral and frontal overlap of adjacent sheets should be the same as recommended by the material manufacturer. An increase in the size of the overlap leads to unreasonable overspending of the roofing material, and a decrease in the size leads to possible roof leaks. Short overlaps can create a blown joint, into which snow or rainwater driven by the wind will break through, or melt water as a result of capillary suction of the joint gap.

The free eaves of the roof must also be as recommended by the manufacturer of the roofing material. A short overhang does not provide water drainage from the roof. Part of the water, rolling over the edge of the roofing material, will be torn off by the wind and thrown onto the wall, and the other part, as a result of the surface tension of the water, overcoming the force of gravity, will flow up the lower plane of the roof and will wet the wooden crate and filly rafters. A long overhang drains water well, but can be cut or bent (for flexible roofs) by snow sliding from the roof (Fig. 4). And it’s good if the roof breaks off at the place of a free overhang, it often happens the other way around, the roofing material breaks much higher, right above the room that the roof should protect.

rice. 4. The roof of this house was laid in the summer of 2008, the photo was taken in the spring of 2009. As expected, in March 2011, sliding snow broke off the roof overhang, breaking the slate above the middle of the sheet. There are no photos of the destruction (didn't have a camera with me). Bottom line: a roof with a free overhang of 20–25 cm was able to “survive” without loss, only two springs

Rainwater and melted snow bags are dangerous on valleys - the inner corners of the intersections of two perpendicular slopes. Here two streams of water flow down into a corner, and the valley becomes a tray for water. To prevent roof leakage in valleys, in all cases and for any type of roof, a continuous crate is made and sheathed with roofing tin (Fig. 5), and the roofing is already laid on them. Or a special waterproofing carpet is laid in this place, provided for such units by the manufacturer of a particular roofing material.

rice. 5. The traditional solution for the installation of a roof valley assembly

Infrequent hurricanes passing through central Russia rarely destroy the roof truss system, but they are able to remove a dilapidated or poorly fixed roof from a house. The tangential forces of the wind acting along the slope of the roof can disrupt its individual elements. To prevent this from happening, install anti-wind brackets for roofs from corrugated roofing sheets, T- and L-shaped brackets for metal roofs (Fig. 6), tie a special type of tile to the crate. From the side of the gables of the building, a wind board is installed (Fig. 5). Wind braces can serve a dual function: to keep the roofing material from being blown away by the wind and to resist tearing away from the action of sliding snow. This is especially true for mansard roofs with a large slope of slopes, where there is no snow, and the roofing material is fixed almost vertically, its weight can be partially transferred to the brackets. To hold piece roofing elements on steep mansard roofs, the brackets must be pre-treated with hot drying oil and painted at least twice.

Influence of water vapor and air temperature

The topic of ventilation of the under-roof space is discussed in the section "Roof insulation".

Solar radiation and temperature changes

Different materials have different sensitivity to solar radiation. So, for example, solar radiation has practically no effect on ceramic tiles, as well as on materials made of metals without polymer coatings applied to them. On the other hand, paint and varnish materials are subject to significant destruction, which manifests itself in the form of paint cracking on a metal roof. A number of materials do not change their physical properties, but lose their visual appeal - for example, they fade (paints and some polymer coatings). When choosing a roofing material, you should make sure that it has sufficient light resistance.

As enclosing structures, roofs function in a rather rigid mode, being influenced by temperature differences. As you know, all materials are subject to thermal expansion and compression to some extent. Therefore, in order to avoid deformations and destruction, it is very important that the materials working in a single structure have similar coefficients of thermal expansion, or appropriate technical solutions are applied to ensure their joint operation. In other words, when installing the roof, you must follow the instructions that the roofing manufacturer offers.

Chemically aggressive substances contained in the air

For a number of materials, frequent, sometimes daily temperature drops from plus to minus can carry a serious danger. It tends to occur in areas with mild and wet winters. Therefore, in such climatic zones, it is necessary to pay close attention to such an important characteristic of materials as water absorption. At high water absorption at positive temperatures, moisture penetrates and accumulates in the pores of the material, and at negative temperatures it freezes and, expanding, deforms the very structure of the material. As a result, progressive destruction of the material occurs, leading to the formation of cracks.

As a rule, in large cities or near large enterprises, a fairly high concentration of chemically aggressive substances, such as hydrogen sulfide and carbon dioxide, is observed in the atmosphere. Therefore, for all elements of building envelopes in such areas, it is necessary to use materials that are resistant to chemicals present in the air.