Roof ridge unit. Traditional roofing units. Types of flat roofing

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

But professionals know that it is not the architectural element itself that matters. Construction Materials, but how they fit into the architect’s plan. A house with a flat roof can look no less elegant than with any other roof structure!

Device flat roof

Especially among undeniable advantages flat (soft) roof:

• Relatively low cost and available materials;
• Easy installation roofing;
• Ability to fully utilize the space under the roof and the roof itself;
• Safety in operation;
• Unlike roofing work, which uses other materials, installation of a flat roof can be done in the cold season using special technologies.

Types of flat roofing

Soft roofing can be of two types: non-exploitable and exploitable. The first is the usual flat roof(For example, multi-story building), which only builders climb to repair and maintain.

Operable 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, open and winter gardens, arrangement of parking for cars, helipad and so on.

Design Features

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

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

Pie flat roof

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

• Roofing technoelast layer;
• Leveling screed made of DSP;
• Vapor barrier layer;
• Thermal insulation layer (extruded polystyrene foam);
• Two layers of waterproofing;
• Leveling reinforced cement screed;
• Polyethylene film;
• Expanded clay layer (along the slope);
• Layer of glass insulation;
• Reinforced concrete slab.

In such cases, the 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 an unused roof covering, the quantity upper layers will be smaller, but the principle of the roof structure and the materials used remain unchanged: base - vapor barrier - insulation (mineral wool slabs) - waterproofing from roofing roll materials.

Since the top waterproofing layer is exposed to the aggressive influence of the external environment (temperature changes, moisture, wind), and if it is damaged, the entire roof suffers, experts have developed an inversion, that is, the reverse order of placing layers: base - waterproofing - thermal insulation - protective material (for example, the so-called geotextiles). The top of 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 roof covering adjoins the walls (parapet) of the building or encircles chimneys, ventilation pipes, lightning rods, etc., interfaces with external drains.

In such places, installation is done especially carefully and carefully - if the tightness of the joining seams is broken, moisture penetrates inside. Therefore, roof components are usually additionally waterproofed (for example, using bitumen mastic).

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

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

Mounting points

Basic layers of a flat roof

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

• Roofing technoelast layer;
• Technoelast lining layer;
• Top layer of insulation;
• Bottom layer of insulation;
• Vapor barrier layer;
• Concrete base or base made of metal corrugated sheets.

For fastening, a roofing disc dowel with a diameter of 20 to 190 millimeters and a long screw (FBD; FBS) or concrete screw are used. The length of the dowel is taken 10-20% less than the thickness of the roofing. The screw must penetrate into the corrugated sheet or concrete base by at least 20 millimeters, and the covering must be fastened 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 should be< 20 см.
• When mounting a roofing pie to a corrugated sheet or to wooden slabs, it is pierced with a dowel assembled with a self-tapping screw. IN concrete base You need to pre-drill a mounting hole for a dowel or concrete screw.
• The mounted dowel must fit tightly to the surface to be attached.

Mount the coating to the base through its penultimate layer using a screwdriver without shock loads (rotation speed - 1500-2000 rpm). After fastening, the final layer of coating is fused to cover the dowel head.

Junction nodes

Roofing device

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

At the junction of the roof and the walls, transition sides are installed and the roofing carpet is attached to the base in the same way as described above. For concrete and reinforced concrete foundations, you can use mechanical fastening with screws and fusing (gluing) an insulating layer, or combine these methods for reliability.

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. This mastic can be used 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 well 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 assemblies

Roof waterproofing

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

Typically, modern roofs have a complex structure and considerable cost, so the slightest violation of the technology for their creation leads to the collapse of the roof and large financial losses. Therefore, the manufacture of a metal roof requires strict adherence to the rules and recommendations of roofing material manufacturers.

General information about metal tiles

This popular roofing material is made from sheet steel: depending on the type, 0.4-0.6 millimeters. To prevent the metal from being subjected to corrosive processes, it is galvanized and coated. polymer layer. The polymer prevents rust from appearing and paints the surface a certain color.

Metal tiles have a number of positive characteristics that are the reason for the popularity of this roofing material:

Stages of installation of metal tiles

Finishing the roof with metal tiles is carried out in several successive stages:

• first, the required amount of roofing materials is calculated;
• then check the horizontal position of the ridge on the roof and compliance with the plane of the slopes;
• install the eaves strip necessary for attaching hooks for drainage gutters;
• install roof overhangs;
• lay a layer of waterproofing;
• they make sheathing, while installing reinforcing strips around the locations of chimneys, pipes, valleys, roof ladders, attic windows, etc.;
• attach cornice strips;
• install internal aprons around the pipes and arrange lower valleys;
• lay sheets of roofing material;
• at the final stage, end strips, abutment elements, upper valleys, accessories are installed, and a lightning rod is installed without fail.

The procedure for calculating the quantity of materials

We should not forget about the length of the overhangs, which should be about 5 centimeters, and that the sheets are laid with an overlap (its size for metal tiles is 15 centimeters).

You also need to calculate required amount material for waterproofing. When making calculations, you will need data on the roof surface area and the amount of waterproofing material in one roll; we must not forget that part of it will be used for overlaps. The calculation is made as follows: the roof area is divided by the area covered when using the roll, and the resulting result is rounded up to the nearest whole value.

The number of additional tools is determined by summing the length of the slopes on which they will be installed, and then the resulting figure is divided by 1.9, since the standard length of the bar is 2 meters, and 10 centimeters will be required to form an overlap.

When calculating the number of self-tapping screws for installing metal tiles, it is assumed that per one sheet of material and per linear meter 8 planks are needed.

The correct shape of the roof structure

Most often, owners of private households install a gable, hipped, or, less often, single-pitch roof made of metal tiles. Hip roofs are also popular. This coating is installed if the slope is at least 14 degrees. Metal tiles are not installed on flat roofs.

In some cases, it is necessary to take into account the climatic features of the region. In areas where a lot of snow falls, the roof slope cannot be less than 30 degrees, and preferably 40-50 degrees. In regions with frequent strong winds and small amounts of snowfall, it is better not to create roofs with steep slopes (this parameter should not exceed 15 -20 degrees).

Before installation, check the correct shape of the slopes. This is done quite simply: you need to measure the diagonals of each of them. The horizontality of the ridge is also checked. If distortions are detected, use is used to correct the situation.

Installation of cornice boards

To install the cornice board, grooves are cut into the rafters. This element is necessary to impart rigidity to the rafter system. Grooves are made in the cornice board for attaching hooks for the gutter.

Installation of waterproofing

IN last years Membrane materials that have appeared relatively recently are used to provide waterproofing for roofing. When a roof is made of metal tiles, bituminous materials (for example,) are not allowed. Waterproofing materials laid out starting from the bottom of the roof towards the ridge. The overlap of two adjacent sheets of material should be 15 centimeters, and a construction stapler is used for fastening. The waterproofing is laid with a slight sag, and the joints are taped with adhesive tape.

Creating a sheathing

Sheets of metal tiles are mounted on a sheathing, which is assembled from boards with a cross-section of 30x50 millimeters. The initial lathing, located at the very bottom, is made a little thicker - 15 -20 millimeters, since it is used to support overhangs. The first of the battens is aligned with the cornice. The distance between the first sheathing board and the second should be 280 millimeters, and subsequent ones are fastened at intervals of 350 millimeters. Thus, it is necessary that the pitch of the metal tile matches the pitch of the sheathing.

When the sheathing is created at the location of the valleys, the location chimneys and other elements, additional (reinforcing) strips are mounted.

Installation of curtain rod

Then the eaves strip is installed, but the metal tiles are not yet installed; they are fastened with galvanized self-tapping screws in increments of 30 centimeters in tension. Otherwise it will make an unpleasant rattling sound. Here they also observe overlap at joints of 50 - 100 millimeters.

Installation of internal aprons and valleys

When the metal tiles are installed, the valley and internal aprons are made from ready-made parts. If required, read. Endovs are arranged in internal corners, installing additional waterproofing and continuous sheathing underneath. A porous seal capable of self-expanding is placed between the metal tile and the lower valley.

The procedure for laying sheets of metal tiles

Before laying the material, logs are assembled, which are necessary to lift the sheets onto the roof. Metal tiles are allowed to be laid on both sides of the first sheet. If the next sheet is placed on the left side, then the last wave is covered on top, and then fastened. When this is done by right side, then the subsequent material is overlapped under the previous sheet.

Regardless of whether a hip roof is created from metal tiles or it will have a different shape, it is customary to align the sheets of material horizontally along the eaves. There are several ways to install this roofing material.

Option one - the sheets are installed from right to left in one row.

The operating procedure is as follows:

• the first sheet is placed on the slope and the material is leveled along the cornice and end;
• this sheet is attached to the ridge with one self-tapping screw - it is screwed into the center of the strip of material;
• the next sheet is laid next to an overlap of 15 centimeters, it is aligned with the cornice and connected with a self-tapping screw to the first;
• Similarly, several sheets are mounted and fastened together;
• the block formed from fastened sheets is once again aligned along the eaves and attached to the sheathing, except for the last of them, which is used to create the next blocks of metal tiles.

Option two - the sheets are installed in several rows.

The technology for creating a roof covering looks like this:

• the first sheet is placed on the slope and aligned along the cornice and end;
• the second sheet is placed above the first and secured with one screw at the ridge - the screw is placed in the center;
• both of these sheets are connected to each other using screws;
• the third sheet is placed next to the first, and the fourth is placed above the third;
• the prepared block, consisting of four sheets, is leveled and mounted to the sheathing.

Option three - installation on triangular slopes.

To implement it:

Installation and operation of a metal tile roof, detailed in the video:

Common mistakes

There are a number of mistakes, most often made by inexperienced roofers, and they can lead to a decrease in the quality of roof installation work.

There are rules that must be followed when creating a roof made of metal tiles - its units are equipped according to a certain technology:

• It is not allowed to cut sheets using a tool such as a grinder, as this leads to the destruction of the polymer coating and its rapid failure;
• to fasten metal tiles, use self-tapping screws only with sealing rubber washers;
• You can walk on the roof covering in shoes that cannot damage it - the soft sole should not slip. You need to step into the deflection of the wave and the location of the sheathing;
• screws are screwed only into the deflection of the wave on the sheet if the fastener is made to a wooden sheathing, otherwise the material will not be securely fastened;
• When installing, you need to take into account the pitch of the wave on the metal tile, it must correspond to the distance between the sheathing boards;
• It is necessary to remove the film from the material, otherwise it will stick and you will not be able to do this job accurately.

Options for other uses of metal tiles

Metal material for creating roofing can be used not only for arranging the roofs of buildings, but also for constructing fences. You can often see a fence made of metal tiles or another cheaper roofing material - corrugated sheeting. This type of fencing looks modern and beautiful. It is not only very convenient to install, it is easy to care for. A fence made of corrugated sheets or metal tiles is durable and attractive in appearance.

A prerequisite for constructing a fence from these roofing materials is the construction of a high-quality foundation, otherwise it will not last long - it will collapse in a strong wind.

Based on the information described above, the installation of metal tiles does not apply to complex work, but without knowledge and compliance with its installation and in the absence necessary tools and skills, this will lead to poor quality work. Mistakes made will result in the roof starting to leak in the first year of operation.

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

Extremely important role Typical roof components play a role in ensuring the reliability and functionality of the roof, which are associated with the junction points of slopes, parapets, various technological communications, etc. The quality of the roof components requires special attention, since they are considered the most vulnerable to atmospheric influences that destroy the coating over time roofing and waterproofing.

Let us dwell separately on some of the most important roofing components.

Parapet assembly of a flat roof and abutment to walls

Structurally, a steel apron or a special strip is installed to make connections to the wall. The vertical part of the latter is attached to the adjacent wall, and the horizontal part covers the roof.

The technology of the connection device for different roof coverings differs only in the method of sealing the seams that inevitably appear during their installation. The impenetrability of the roof largely depends on the quality of this operation.

Typical roofing units can be made either with or without the installation of an additional special niche in the wall, a groove. Sealants are used to seal seams. Today, bitumen-containing compounds that were once popular have successfully replaced silicone ones.

• Roof components covered with profiled metal in areas adjacent to concrete or plastered brick walls perform as follows.

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

If a special strip is used, then a wooden strip is fixed in the groove.

• The vertical part of the protective strip, made of profiled metal, is attached to it.
• The other part lies on the surface of the roof.
• The groove, as in the previous case, is filled with sealant or cement mortar.
• Manufacturers offer strips 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 provided, is placed under the plank and glued to a sealant, bitumen or silicone. The junction strips are joined along the length with an overlap of at least 10 cm.

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

• Having secured the upper apron to the wall, place the lower apron under it and connect it to the upper one.
• It is attached to the roofing with clamps.
• All connecting seams are treated with appropriate sealant.

• For roofs made of natural tiles, the connection is made using a special tape made of corrugated aluminum. It exactly repeats the profile of natural tiles. The joining seams are filled with hot bitumen, which reliably seals all joints, eliminating the penetration of moisture.

On a note

Corrugated aluminum tape and mastic are also used for high-quality moisture protection of the junction points of a roof covered with soft tiles.

• Flashing is considered one of the simple and reliable technologies for performing such a soft roof assembly. The essence this method in performing the following work:

• application of elastic mastic with high hydrophobic characteristics;
• reinforcement of joining seams using a layer of geotextile;
• re-application of the mastic layer.

Roof with parapet and its connections

The design technology for the parapet assembly is almost the same. However, being unprotected, the structure very soon becomes unusable. It is negatively affected by the influence of external factors - precipitation, sudden temperature fluctuations, etc. Brick buildings are especially vulnerable in this sense. In other words, the parapet needs protection. For these purposes, a kind of steel canopy is built over it, equipped with special droppers. It is through them that precipitation is removed. Moreover, the probability of water getting onto the parapet is negligible.

Connections to chimneys

Roofing units of this type are characterized by the presence of high temperatures during the heating process of the chimney. That is why the requirements for tightness when constructing it are not enough; non-combustible materials are needed.

One of the popular options today is a roofing trim for the chimney, which can have different shapes, dimensions and angle of inclination.

Another method of sealing is the use of a roofing apron made of metal 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 us note some features of their installation to brick chimneys on metal roofs.

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

• An apron made of a steel profile is placed against the chimney wall and a mark is made along its upper edge. Along the resulting line, a groove is made on the wall, using a grinder.
• Work begins with the installation of the internal apron.
• After cleaning the groove, its lower element is inserted there and pressed tightly, precisely aligning the upper part with the groove. They attach it to the wooden roof elements with self-tapping screws and seal them using sealant. They're playing him flat sheet, because of its shape it is called a tie, along which water should be drained, and it is directed towards the cornice or valley.
• Similarly, trim and install the apron elements on the sides and top, overlapping adjacent parts with an overlap of at least 15 cm.

• External apron. Installation of the outer apron begins after laying the roofing material. Its installation is no different from the installation of the inner apron, with the only difference being that the upper edge of the outer apron is not recessed into the groove. Instead, the joint is sealed using special sealants.

Junction of roof slopes

The internal junctions of roof slopes, or valleys as they are called, are considered the most difficult units 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 potential danger occurrence of leaks. A lot of different debris that accumulates moisture or ice always accumulates here.

Methods for ensuring watertightness depend on the characteristics of the roof covering. General principle The execution of the units comes down to installing roofing iron elements under the covering, repeating the shape of the angle of connection of the slopes.

• For metal roofing, standard lower valleys are used. Their edges are folded so that water cannot get under the coating. The junctions are treated with sealant or a self-adhesive porous seal is used. The junction on top of the roofing covering is covered with decorative strips that match the color of the covering.
• For sealing roof components made of flexible tiles A continuous waterproofing carpet is laid on the valley.

Connection of technological passages of the roof

An excellent solution for these units is Master Flash roofing trim. It is made of rubber, which is resistant to various influences, in particular temperature. The indisputable advantage of the Master Flash design is the ability to use it to seal a unit of any diameter, even the passage of a television cable. It is enough to select a cutting of a slightly smaller size 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 unit, silicone sealant is used.

On a note

Master Flash is available in a variety of colors to match modern roofing materials.

Currently, due to the emergence of not just new materials, but entire SYSTEMS of enclosing structures (consisting of heterogeneous 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). These factors include, in particular: precipitation; water vapor in the external and internal air of the building; wind; solar radiation; temperature changes; chemically aggressive substances contained in the air, as well as some other components of the processes.

Influence of precipitation and wind

The wind throws water or snow onto the roof with force, which, if the design of the roof and the roof as a whole or its individual components is not well thought out, can lead to a leak in the roof as a result of water or snow getting into the joints of the roofing materials. In addition to rain, melting snow also affects the roof. The most vulnerable places on the roof for leaks are the frames of chimneys and ventilation pipes and the junction of the roof with various vertical surfaces: walls, gables, dormer windows.

The traditional technical solution for connecting roofs to walls and parapets, both frontal and lateral, involves making niches and grooves in the walls (parapets) along the entire length of the connection and installing galvanized steel roofing aprons in them. It is permissible to install aprons made of black roofing sheet, twice treated on both sides with hot drying oil and painted at least twice. Installing an apron without a niche or groove by pressing it tightly against the wall does not provide a proper connection, and the unit leaks. There are at least two reasons for this: firstly, the walls are not so smooth that it is 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, moving away from the wall (Fig. 2).

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

Installing the upper part of the apron in a niche or groove eliminates this problem; here the 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 installing it in a groove, it is advisable to seal it cement-sand mortar. It must be added right away that simply filling a high niche with mortar is practically useless, the mortar from there will crumble 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 groove, where it will melt and melt water will flow under the iron. The aprons are fastened with nails to antiseptic wooden plugs, previously laid in the wall, for example, during the construction brickwork. The installation pitch of the plugs is about 1 m. If you attach the apron to the plugs before installing wooden blocks triangular section, then plugs can be installed less frequently, and the edge of the apron will be pressed tighter. Securing the apron with a second triangular block will make the knot practically waterproof. You can plaster the groove and forget about it until the iron of the apron rots.

Along the length, the apron elements are mounted overlapping in the direction of the water flow. The overlap is made at least 10 cm. If the joining of the aprons is done not with an overlap, but with a lying seam, the knot will be more reliable.

To protect the junction of the roof and the parapets, a “roof” made of roofing steel, equipped with drip edges (curved “hook” edges), is installed on the latter. A parapet apron with drips extended beyond the walls protects the parapet from rain: water is diverted from the walls through drips, drops break off and fall directly onto the roof or onto the apron of the junction unit. There is less water flowing directly down the walls. The parapet apron is secured by pulling it onto T-shaped spikes, installed in increments of about 1 m and attached, in turn, with nails to antiseptic wooden plugs. In order to prevent the parapet apron from being torn off by a strong wind, it is allowed to fasten it from above with screws (with self-tapping screws into a wooden plug) through the roofing sheet with the installation of rubber washers under the screw head.

The junctions of roofs to chimneys and ventilation shafts. 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 placed under it. The aprons are covered from above 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. In case of heavy winter snowfalls, the snow gets under the inner side of the iron; the specified dimensions of the apron will prevent melt water from penetrating under the roof. It will simply dry out after traveling a long way.

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

In pipes, especially chimneys, the installation of wooden plugs is unacceptable, so the apron is fastened on lying seams, connecting all the roofing iron around the pipe into a single whole. If roofing is being done around ventilation shafts, then the apron can be fastened with nails to antiseptic wooden plugs. Cuts around round pipes, such as asbestos-cement or PVC pipes, are clamped with another pipe larger diameter. The gap between the pipes is filled with molten bitumen 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 oil paint or bitumen primer. After caulking, the gap is filled with sealant or covered with a greasy cement-sand mortar.

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

The free overhang of the roof should also be as recommended by the manufacturer of the roofing material. A short overhang does not ensure 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 sheathing and rafter fillies. A long overhang drains water well, but can be cut or bent (at flexible roofs) snow sliding from the roof (Fig. 4). And it’s good if the roof breaks off in a place where there is a free overhang; more often it happens the other way around, the roofing material breaks much higher, right above the room that the roof is supposed to protect.

rice. 4. The roof of this house was laid in the summer of 2008, the photograph was taken in the spring of 2009. As one would expect, in March 2011, sliding snow broke off the roof overhang, breaking the slate above the middle of the sheet. There are no photographs of the destruction (I did not have a camera with me). Result: a roof with a free overhang of 20–25 cm was able to “survive” without losses, 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 meet, flowing into the 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 sheathing is made and sheathed with roofing tin (Fig. 5), and the roofing covering is laid on them. Or a special waterproofing carpet is laid in this place, provided for such units by the manufacturer of the specific roofing material.

rice. 5. Traditional solution for constructing a roof valley assembly

Infrequent hurricanes passing through middle lane Russia is extremely rarely destroyed rafter system roofs, but they are capable of removing dilapidated or poorly secured roofing from a house. Tangential wind forces acting along the roof slope can tear off its individual elements. To prevent this from happening, install anti-wind brackets for roofs made of corrugated roofing sheets, T- and L-shaped brackets for metal roofs (Fig. 6), and tie a special type of tile to the sheathing. A wind board is installed on the gable side of the building (Fig. 5). Anti-wind staples can perform a dual function: to keep the roofing material from being torn off by the wind and to resist lifting from the action of sliding snow. This is especially true for attic roofs with a large slope, where there is no snow, and the roofing material is fixed almost vertically, its weight can be partially transferred to the brackets. For holding piece roofing elements on steep mansard roofs The staples must be pre-treated with hot drying oil and painted at least twice.

Effect 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. For example, solar radiation has virtually no effect on ceramic tiles, as well as on metal materials 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 cracking of paint on metal roofing. A number of materials do not change their physical properties, but loses its visual appeal - for example, it fades (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 harsh mode, experiencing the influence of temperature changes. As is known, all materials are subject to thermal expansion and compression to one degree or another. Therefore, in order to avoid deformation and destruction, it is very important that materials operating in a single structure have similar coefficients of thermal expansion, or that appropriate technical solutions are used to ensure their joint operation. In other words, when installing the roof, you must follow the instructions offered by the roofing manufacturer.

Chemically aggressive substances contained in the air

A number of materials can be seriously endangered by frequent, sometimes daily, temperature changes from plus to minus. This 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. With high water absorption under 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 in the atmosphere there is a fairly high concentration of chemically aggressive substances, for example, hydrogen sulfide and carbon dioxide. 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.

Before starting any construction works, it is necessary to draw up a plan according to which specialists or home owners will act. For example, before arranging the roof of a private house, you should create a project, which is one of the most important tasks.

Design Features

If you are not one of those people who are familiar with all the components of the roof structure, and do not know how to draw up a diagram or drawing of the roof, then you should use special computer programs similar to Autocad, it will be enough to enter the size data into it, select a certain type of roof - and the program will select standard schemes. This will allow you to create a high-quality drawing by calculating the roof components. But if you draw up sketches yourself, you should coordinate the style of the house and the roof, and determine the color of the roof.

Features of calculations

It is important to carry out calculations that will take into account the expected load on the roof. The system drawing will include the main roof components. This should include materials, tools and fasteners. Design requires mandatory calculation of the roof area. This is required to correctly determine the consumption of material, thermal insulation and fasteners. If you line up pitched roof, then calculating the area will be very simple. Its shape is a rectangle, and to determine the area, the width should be multiplied by the length. In addition, 0.5 m on each side should be added for the roof overhang.

What else you need to know about design

If we are talking about gable roof, then the area should be calculated similarly, taking into account the length of the rafters and the roof overhang at the eaves and gables. The roof attachment points for such a system are more complex, but calculating the area is not difficult. The design will need to be divided into separate figures and use school knowledge of geometry, which will allow you to calculate the area of ​​​​each of them. Ultimately the numbers add up. Before starting system design, it is important to take into account the snow load in winter time, since insufficient roof slope can cause additional loads. If the snow does not clear from the roof surface, this will increase the mechanical load on the rafter system.

Material selection

The roofing units will also pass through the covering material, so it is important to think about which one will be easier for you to work with. As you know, when building a house, the most expensive element is the roof. And the choice of roofing material is important stage, since an attempt to save on it can lead to increased costs during operation. The roof should protect the entire building and extend its lifespan. A fairly popular roofing covering is slate, the constituent elements of which are asbestos and cement fibers. This material is ready to last about 40 years, but among its additional positive characteristics are:

• low cost;
• resistance to low temperatures;
• resistance to mechanical stress;
• simple installation procedure;
• no overheating of the sheet in hot weather.

Roofing units can be easily arranged when choosing slate, in addition, the roof will have excellent thermal insulation qualities, it will absorb sound and exhibit fire resistance characteristics. But slate also has disadvantages, they are expressed in a decrease in waterproof qualities over time, the possibility of the emergence and development of moss and lichens, as well as the fragility of the sheet edge. If you want to equip a reliable, inexpensive roof, then slate will be an excellent solution. The main competitor of the above material is steel roofing. This material is inexpensive and can be used for complex configurations.

In modern construction, 0.5 mm galvanized steel is most often used to cover roofs, which is coated with an anti-corrosion zinc layer during the manufacturing process. Positive qualities are ease of installation, low cost, possibility of coating complex structures and low weight. However, there are also disadvantages, they are expressed in increased noise levels and unattractive appearance.

Alternative options

When choosing a roofing covering, you can pay attention to aluminum, which is used in the manufacture of metal tiles and for the manufacture of aluminum tiles, material is used in rolls that has the necessary coatings. The covering material is lightweight and can be used on almost any sheathing system. If you use the folding method and clamps, then when installing the roof you may not have to drill a single hole in the material.

The service life of aluminum roofs can reach 150 years, which is the main factor that forces consumers to purchase these covering materials. Metal roofing has also become popular recently. When making sheets, a coating is applied to the surface, which ensures durability and strength. The upper composition of the layer protects the material from corrosion, and on the construction market you can find a wide range of metal tiles, which are presented in products different colors and forms.

Corrugated roofing consists of corrugated metal sheets that combine the positive characteristics of metal tile roofing and steel covering. Sheets may have polymer coating and have low cost. If you choose this type of roofing, you will face the same problems that owners of houses with galvanized steel and metal roofs face. However, this type of material also has the advantages of a galvanized metal tile roof. Depending on the specific type of coating, the service life can vary from 10 to 50 years.

Installation of the rafter system

Nodes rafter roof must be as durable as possible, since the reliability of the future roof depends on this. You can strengthen it with pins, nails, and nail plates. When using studs, the rafters in the upper part must be butt-joined, and they will be held together by linings made of waterproof plywood or metal. The upper part of the rafters can be connected with nails; for this it is best to use special staples. This technology is inexpensive, reliable and quite simple. They are sometimes used and are made of galvanized steel and stamped teeth. The height of the last elements should be 8 mm, and the number of rows of nails will depend on the size of the component parts.

Installation of cornice strips

The roof eaves assembly is necessary to protect the wooden sheathing from the negative external influence of precipitation. Installation cornice strips It is quite simple to produce; to do this, they are nailed to the sheathing with nails in a checkerboard pattern, the distance between them should be approximately 30 cm. Also called wind guards, they will protect the roof from precipitation getting under the metal tiles. They are installed on top with a bend on the cornice, and the distance between them should be approximately 35 cm.

Connecting to a wall

The connection of the roof to the wall ensures that the roof can cope with its main task and reliably protect the home from wind and precipitation. The junction is quite easy to arrange; it is one of the most suitable building materials for such installation work. When the roof is connected to the wall, there must be a gap between the vertical elements, which is necessary to ensure natural air circulation in the roof cavity. The design of this connection involves the use of elements from sheet metal. Installation of the apron cannot be carried out without gating a section of the wall structure. At a height of 20 cm, a gutter should be made, the depth of which will be 3 cm. The edges of the element are treated with sealant, and the upper part is installed in the groove.

The lower part of the product must be pressed to the roof surface with fasteners, which are equipped with a rubber gasket. If you use a double apron design, you should ensure a higher degree of sealing. At the same time, you can refuse to groove wall structures. The upper element of the apron is fixed to the base using dowels, then the lower fragment should be installed under the base, which has a lock that ensures a reliable connection.

Pipe sealing

Sealing the pipe on the roof will ensure proper operation of the heating device. When finishing a chimney, you can use a so-called collar made of rectangular metal sheets. Their width should be 40 cm. To finish the chimney on a tile roof, you can use a lying seam connection. Sealing a pipe on the roof of a pitched structure, the slope of which is 30° or more, involves installing a special beam that will protect the back of the pipe from rainwater.