Sheath fastening. Lathing step under the metal tile. Necessary materials and tools

One of the obligatory elements of the arrangement of the roof is the crate, which is a bar that is perpendicularly laid on the rafter legs. The crate takes on the load of the roofing material, transfers it to the rafters, and they transfer pressure to the load-bearing walls. Proper installation of the crate is a responsible and difficult task, the implementation of which is best entrusted to professional builders.

beam;
board;
plywood;

There are two types of roof battens:

The sparse roof lathing is characterized by a gap between the bars of several centimeters.

A solid crate is laid on a sparse one. For this, fiberboard, laminated chipboard, boards can be used. The boards are laid at a distance of 1 cm from each other at an angle of 45 ° to the boards of the sparse crate. The gap between the boards is necessary in order to extinguish the thermal deformation of the wood. It is better to use a tongue-and-groove anisept board.

A continuous layer may be the only one laid directly on the rafters.

Crates are single-layer and double-layer. The first layer must be laid parallel to the ridge, horizontally. The step can reach 50-100 cm. It can be the only one, or it can be used for flooring over the second layer.

Important ! The roof deck should not have sags or bumps, especially if a fragile long material is used as a roof, for example, slate.

The flooring must be strong enough to support the weight of a person. Otherwise, while walking on the roof, the fastenings and joints of roofing parts are broken, and this leads to leaks.

How the installation of the crate will be carried out largely depends on the material chosen for the roof. As an example, let's take one of the most popular materials - metal tile.

Laying anti-condensation film

In cases where roof insulation is provided, an anti-condensate film will be needed, which will protect the insulation from condensation and blowing. Without a film, the crate and rafters are ventilated, and the attic will be cold. When arranging a crate for a metal tile, such a film spreads on the rafters in horizontal stripes over the entire roof area with an overlap of 10-15 cm. It should not be stretched, the film should sag between the rafters. The structure is fixed with bars equal in cross section to the width of the rafters with a thickness of 3 cm.

Installation of the crate under the metal tile

After the laying of the film flooring is completed, you can proceed to the installation of the crate, on which the metal tile will be fixed. In cases where the laying of the film is not provided, the horizontal lathing is done directly on the rafters. All horizontal boards used must be antiseptic. The cross section is 2.5-3 cm by 1-1.5 cm. Any inch can fit, but it is very important that the thickness of all the boards to be laid is the same. Proper selection of thickness guarantees a flat roof plane. Not only the functionality, but also the appearance of the house depends on this. The only exception is the bottom board, which should be one and a half centimeters thicker than the rest.

Important ! The bottom board is attached first. So that in the future the boards do not twist, they are immediately fixed in two places with screws or nails.

Sheathing ready for installation of metal tiles

Board pitch calculation

The step is selected in accordance with the profile and type of metal tile. Usually the distance between the bars is indicated in the instructions and is considered from the bottom of the first board to the top of the second. Between the first two boards, this value should be smaller.

The size of the step is also influenced by the size of the ledge of the roof for the first bar, and the slope of the roof slope. The calculation of the step is made taking into account the drain. If it is attached to the frontal board, then 30 mm is added to the protrusion. The diameter of the gutter also affects the length of the ledge.

The protrusion of the material is counted either from the frontal board, or, if it is not there, from the rafter cut. The length to which the metal tile should be lowered depends on the roof slope. The steeper it is, the lower the material has to be lowered.

Step by step installation instructions

For rafters, a timber with a size of at least 50 * 150 mm is selected, for a crate - with a cross section of at least 25 * 100 mm. The counter-lattice can be made from a board 25 * 50 mm.

The pitch of the rafters is usually 600-900 mm.

The initial board is nailed along the cornice overhang, and it should not protrude beyond the overhang. To compensate for the difference in the levels of the fulcrum of the tiled modules, this board, as already mentioned, should be thicker than the rest by a centimeter and a half.

The step between the board facing the eaves should be 50 mm less than the step between other boards. To check the correctness of this distance, two cutting boards are laid out on the ground, on which a tile element is superimposed. This is how it is determined whether the protrusion is sufficient, whether it can provide a normal flow of water. If the protrusion is larger than required, water will overflow through the gutter. If, on the contrary, it is less than it should be, water will be blown between the frontal board and the gutter. In addition, if the protrusion is too long, the sheets can be deformed from excessive snow load.

The device of the crate under the metal tile requires care

After marking, the ridge and end strips are fastened.

The wind board is attached above the crate exactly to the width of the metal tile sheet, that is, 35-55 mm, depending on its type.

In order to securely fasten the ridge, boards 25 * 100 mm are nailed at the points of attachment. This will help you install it later.

If it is planned to arrange a drain before the roof is mounted, it is necessary to install brackets to which the gutters are attached. Brackets are installed on the bottom board with a step of 500-600mm.

First, the extreme brackets are mounted in such a way as to calculate the slope of the gutter per 1 meter of length (was 5 millimeters). Then a cord is pulled along which the rest of the brackets are attached. Also, before the metal tile flooring, a cornice strip is mounted along the roof overhang.

The gutter is mounted on brackets, then the cornice strip is fixed so that its lower edge overlaps the edge of the installed gutter. In this case, the condensate flowing from the bar will fall into the gutter. The overlap of the cornice strips must be no less than 100 mm.

At the junctions (pipes, ridges, valleys, skylights, etc.), a solid type crate is installed.

After performing all of the above operations, you can proceed to the direct installation of the metal tile.

The crate is the basis of both the roofing and rafter system of the house.

It is worth remembering that the service life of your roof depends on many factors, both on the quality of installation and on the service life of components. Much depends on how correctly the crate is installed: the appearance of the entire structure, the service life of the roof, the safety of the house, and even the reduction of rain noise. And since its arrangement requires experience, knowledge of the nuances and subtleties, it is desirable that its installation be entrusted to professional installers.

Most materials are attached to the building envelope not directly, but through an "intermediary". This is both more convenient and, if necessary, simplifies repairs. In some cases, this method of installation is a mandatory technological condition. A specialized frame designed for such installations is called a crate. Further in the article, we will talk about how the crate is being installed, what it happens to be, and according to what rules it is calculated.

Although the most common design in which the crate is used is pitched roofs, there are other planes where it is suitable. The most popular option is a wooden crate, but there are also metal structures.

The order of work is usually the following:

If there are bulges on the rafters at the points where the beam passes, they are cut off
In the case when a vapor barrier device is planned, it is laid on the rafters, fixed with a stapler. At the same time, the laying starts from the ridge, with the overlapping of the panels through it. If the membrane is transparent, the measuring cords can be removed completely. Otherwise, the film is slipped under the twine when laying
If there are recesses on the rafters under the future timber, they are leveled with stuffed rails, a set of pieces of roofing material of the desired thickness
Beams or boards begin to be fixed from the ridge beam, depending on the coating material and the chosen method of arranging the ridge assembly - at a distance from the run from 40 to 150 mm for each slope
As a rule, the crate is installed in pieces, while simultaneously closing the area of \u200b\u200bthe slope, determined by the length of the existing beam or board. Then move on to the next run.

Important information! It rarely happens that a wooden crate is made from a solid board or timber. As a rule, the standard length of lumber is much less than the length of the slope. Therefore, the elements of the crate have to be spliced along the length. This is done in such a way that the joint of the beam falls on the rafters, the edges of both spliced pieces are fastened with nails. It is important to ensure that in adjacent horizontal rows the joints are displaced, falling on different bars. To do this, the lumber is cut to the appropriate length.

Regardless of what the main distance between, in the places of valleys and grooves (concave joints of slopes), it is arranged solid, possibly using sheet material, sometimes tin
Under the elements passing through the roof - various parapets or chimneys, their own crate is arranged, which is calculated separately. For example, for a chimney - it should be in any part of it at a distance of at least 150, and without thermal insulation for ceramic pipes - and 250 mm

ADVICE! The lathing should be arranged in dry weather, immediately before laying the roofing material. Wet bars or boards will definitely begin to warp

Immediately after the installation of the crate, a layer of insulation is laid, if one is designed, and a waterproofing film is attached over the beams with a stapler

With the advance calculation and cutting of lumber, the installation of the crate is greatly accelerated and takes less effort. Therefore, additional time should be devoted to preliminary preparation, and it should be done qualitatively.

Lathing installation- This is one of the key stages in the arrangement of the roof. It is on the crate that the roofing will be based in the future, which means that the strength of the roof itself largely depends on the correct installation of the crate and the strength of its elements. So, if you want to build a roof that will last you for many years without major repairs, take note of the recommendations and useful tips that will be outlined below.

Types of roofs and the main elements of the roof structure

In the construction of private houses, summer cottages and country cottages, the technology of erecting gable and four-slope (hip) roofs is most often used. In the construction of garages and ancillary buildings, a pitched roof is also used.

Rafters are wooden beams that are the frame for the roofing "pie". There are several approaches to . For example, they can protrude beyond the outer walls of a building, creating a foundation. Rafters can be fastened with nails, staples and special sliding joints.

Roof overhang is the lower part of the rafters that protrude beyond the outer perimeter of the building.

The ridge is the upper part of the roof, its “peak”, which is formed at the place of the inclined connection of the rafters.

Waterproofing, thermal insulation and vapor barrier are the layers of the roofing "pie" responsible respectively for protecting the under-roof space from moisture, cold and condensate, which can accumulate due to the lack of free air circulation.

Now that you are armed with the necessary terms, let's get straight to the question. framing installation.

What is the installation of the crate for?

The first and main function of the crate is a support for the roofing. During the installation of the crate, the problem of uniform distribution of the load from the weight of the roof onto the truss system is solved.

In addition, if you are planning, you must be aware that between the outer (cold) coating and the insulation layer there must be a ventilation gap and a membrane that protects the insulation from waterlogging with condensate and precipitation that can get inside due to depressurization of the roof. This gap is created due to the thickness of the lathing bars, and the waterproofing layer, which is attached to the lathing, serves as a protective membrane.

What can be the crate?

Such a crate is used in the arrangement of roofing made of ceramic tiles, metal tiles, slate, corrugated board and other rigid sheet materials. In the process lathing installation this type of gaps are left between the boards. As a rule, the fastening step of boards / beams depends on the size of the sheet of roofing material.

Solid crate

Such a crate involves fastening boards end-to-end or replacing them with plywood, OSB or chipboard sheets. A continuous crate is used in the construction of roofs made of soft rolled materials (soft tiles, roofing material, etc.). The main advantage of such a crate is the finished appearance of the roof from the side of the attic, as well as a flat surface on the outside, which greatly facilitates the process of laying roofing material. The disadvantage is the high consumption of materials for the arrangement of the crate.

What materials and tools will you need?

The main consumables are:

The bar is not lower than I grade, without knots, from 6 meters long. The cross section of the beam should be 50x50 mm for metal tiles, 75x75 mm for ceramic tiles.
Edged board not lower than grade II, with a minimum number of knots, from 6 meters long. The cross section of the board is from 25x100 mm. If you plan to equip a solid crate, then it makes sense to replace the boards with plywood, OSB or chipboard panels.
Nails, the length of which should be 3 thicknesses of the timber you have chosen. For example, if you use a beam with a section of 50x50 mm, then the length of the nails should be 15 mm.
Staples for a construction stapler.

Prepare the following tools in advance:

Hacksaw or chainsaw;
Construction stapler;
Roulette;
Building level;
A hammer;

The actual arrangement of the crate

Before you go to lathing installation, stretch two ropes along the diagonals of the roof slope, and then compare their lengths. The difference should not exceed 2 cm, otherwise, due to the irregular shape of the slope surface, problems may arise both when laying the crate and when installing the roofing material.

Next, a waterproofing layer is laid on the rafters (plastic film or special material - at your discretion). Waterproofing is laid in the direction from the bottom up, starting from the roof overhangs. Here it is necessary to leave a margin of 40-50 cm. Next, the material is placed with an overlap of 10-20 cm and fixed on the rafters using a construction stapler. The joints of the canvases are glued with adhesive tape. When all the waterproofing is laid, counter-battens bars are nailed to the rafters on top of it.

The formation of the crate itself also begins from the bottom of the roof slope. The first board is nailed along the edge of the overhang. It is very important to control the location of the edges of the board in a horizontal plane, because it is on this first board that the roofing material will be leveled in the future.

The step of fastening the boards of the crate is determined depending on the size of the sheet of roofing material. Recall that for a soft roof, the boards are stuffed end-to-end on the bars of the counter-lattice. If you are making a sparse crate, you will need a template so that you do not measure the distance between the boards with a tape measure each time. A piece of the same board can serve as such a template.

On both sides of the ridge, one board must be nailed, regardless of the pitch of the crate. The same applies to valleys, chimneys and other complex structures.

On this arrangement of the crate can be considered complete. If you did everything right, the laying of the roofing material should also be successful.

A few words about the metal tile and the principles of its fastening on the roof

In order to correctly understand the principle of creating a crate for roofing from a metal tile, you need to have an idea about the structure of this material and how it is generally attached to the base.

What is a metal tile

So, a metal tile is a profiled metal sheet covered with a special protective and decorative coating. The material of manufacture is most often steel - cold-rolled sheets with a thickness of 0.4 to 0.7 mm. Much rarer, but still found metal-tiled aluminum and even copper coatings. They are, of course, much more expensive than steel ones, so they are not in particularly wide demand.

On the production line, metal sheets are passed through special machines, where, with the help of special shaped rollers, they are given the desired relief due to the plasticity of the metal.

The relief of the coating is designed in such a way that it reliably imitates the natural tile coating. These are the so-called modules located in horizontal and vertical rows, each of which is ready-made and is a “dummy” of piece tiles.

This form of relief, in addition to purely decorative qualities, gives a few more "preferences":

Provides free flow of rain or melt water - it simply rolls down the "steps", and with proper installation, there are no prerequisites for stagnation.
The given relief gives the metal sheet high spatial rigidity. So, the metal tile even outperforms the corrugated board in terms of the permissible load on the transverse bend, while not inferior in terms of the longitudinal bend.

Prices for metal tiles

metal tile

The relief also serves as a kind of "castle" connecting adjacent sheets. Installation from this is greatly simplified, because even if desired, it is difficult to make a mistake. When laying the sheets, they are perfectly combined, overlapping modules one on top of the other, without requiring either longitudinal or transverse alignment. The overlap lines become almost imperceptible, and the tight fit of the "castle" sections guarantees reliable protection of the roof from leakage.

There are many varieties on sale, produced by domestic and foreign companies. Recently, small regional firms have appeared that have purchased and installed production lines, and now they independently produce metal tiles. acceptable quality from finished steel sheets coated, thereby satisfying the needs of demand in the locality and the nearby administrative area. But most often this is done anyway according to the “patterns” of well-established and proven models of well-known manufacturers.

Linear dimensions of sheets of metal

This publication does not aim to consider the aesthetic or operational advantages of metal tiles. We are more concerned with the question of how to ensure that these advantages are revealed in full force, that is, how to create all the necessary conditions for high-quality installation of the coating. But for this it is necessary to get acquainted with the geometric structure of the metal tile - with hermain lineparameters.

The main indicators are shown in the figure below:

1 - the total width of the sheet.

2 - useful sheet width. It is, of course, less than the general one, since the edge half-wave of the metal tile is designed to overlap with the adjacent sheet. When calculating the amount of material for the roof, they operate with this value.

3 - the total length of the metal tile sheet. It depends on the capabilities of a particular manufacturer and on the wishes of the customer. So, various companies offer consumers sheets with a length of 5 ÷ 6 to 8 meters. In fact, you can order material in such a way that one sheet covers the entire length of the slope from the eaves to the ridge. On the other hand, it is not always convenient for installation work at heights - they are difficult to lift a long sheet onto the roof without the risk of deformation. And, in general, it is undesirable to use sheets with a length of more than 4 meters. However, this rule is advisory in nature.

4 - module length or, as more often referred to as the longitudinal pitch of a metal tile. But this parameter is extremely important for arranging the crate, since the distance between its guides depends on it.

The diversity in this parameter is not so great. Most often you have to deal with metal tiles module pitch of 350 mm. Roofing with large long modules of 400 mm is also popular. However, there are models with a length of "tiles" of 300 mm, and models of the "Retro" type are also more "discrete" - with a longitudinal wave pitch of 200 and even 150 mm.

5 - wave height - for profiles of different models can vary significantly. It is generally accepted that the higher the wave, the more pronounced the indicators of the spatial rigidity of the material and its resistance to external bending loads. True, this affects the useful width of the metal tile sheet - it becomes smaller.

6 - it is clear that since the sheet imitates the laying of a real tile, it has a stepped shape - each next module in the direction from bottom to top starts with a step. The height of this step can be different - from 10 to 20 or more mm, depending on the model.

Usually, in advertising materials and in the technical documentation for metal tiles, there is both a sketch of the coating and two diagrams - a longitudinal and transverse configuration of the sheet. Understanding such a scheme is not difficult at all. It is clear that the choice is always made primarily by the external qualities of the roofing material, but knowing its geometric parameters is still no less important.

Prices for ondulin

Below is a table that may help you make a preliminary selection of roofing material. Along with the illustration, it also shows the main linear parameters of the most popular models.

[table id=1924 /]

How does the metal tile adhere and attach to the base?

In order for the roofing material, even with its considerable spatial rigidity, to have the ability to withstand external loads (snow, wind, etc.), it must have a reliable support. And due to the fact that the metal tile is given a stepped shape, each of the modules should have a point, or rather, a support line. That is, each "lower tooth" or, as they are also called, the sole of the profile must rest against the crate element. How it looks is shown in the diagram:

Fastening to the crate is made by roofing screws, which are placed directly under the step. The layout of the fasteners may vary from model to model, but basically they are screwed through one wave, both horizontally and along the slope line. In the edge zones (along the cornice, pediment, valley and ridge and along the sheet overlap line) usually mount produced in each batten guide .

These rules, basically, predetermine the design of the crate for the metal tile.

General principles for the design of the crate

The crate under the metal tile can be created solid or sparse.

Solid crate

A solid crate is mounted from sheets of moisture-resistant plywood or OSB, at least 10 mm thick, or from boards, however, laying them not completely solid, but at intervals of about 10 mm. Both options have their drawbacks.

A solid board of sheet materials is, of course, very even, without any level differences, which sometimes happens with the use of poorly calibrated boards. However, in the context of the topic under consideration, this is where all its advantages end. But there are drawbacks, and very significant ones.

- Firstly, this business is very expensive, since both OSB, and, in particular, plywood will cost much more than ordinary lumber.

- Secondly, the tightest fit of the metal tile at the base over the entire area is by no means a blessing. The high thermal conductivity of the coating will necessarily lead to the formation of condensate even with daily temperature fluctuations. But a ventilated gap for the free evaporation of moisture and the release of water vapor is not provided for with this installation. That is, moisture will begin to accumulate under the roofing with all the ensuing (sometimes it has to be taken even literally) consequences.

Thirdly, if you look again to the diagram where it is shown how the modules of the metal tile rest against the base, it becomes clear that such a crate, in general, is not required at all.

For flexible shingles - yes, this becomes the best foundation. But for sheets of metal tiles, it is quite possible to apply cheaper and more practical solutions.

Prices for ceramic tiles

ceramic tiles

A solid crate of boards, which are located with a small clearance from one another. This design is recommended at small angles of roof slope when installing a roof made of corrugated board, slate or, for example, from ondulin.

But the metal tile is fundamentally different from the roofing mentioned above already in that it rests on the surface not along the entire length in the direction of the slope, but only along the line of steps between the modules.

Let's look at a similar diagram again:

As you can see, some of the guides, and - quite impressive, does not perform any bearing role at all, since the profiled sheet simply does not rely on them (circled for example with a large ellipse). In addition, it is impossible to exclude the possibility that during the installation of sheets of metal tiles, the self-tapping screw will fall either between the boards of the crate, or into the edge of the board, thereby causing a chip or not providing reliability attachment at this point.

In other words, there is no technological need for a continuous board crate, and in terms of the economy of spending materials, it will be great to lose to a sparse one. This can be clearly seen below, when it comes to materials.

Sparse crate under the metal tile

This option appears the most optimal. As it has probably already become clear, it is necessary to place the guide battens in such a way that the sole of each horizontal row of metal tile modules has both a reliable support from below and a sufficient width of the material for screwing in a roofing screw.

The roof is considered one of the foundations that ensure the comfort of the house, protection from the negative effects of atmospheric factors. That is why the process of its arrangement should be organized rationally and correctly down to the smallest detail. It is obvious that the laying of the roofing material must be carried out in full accordance with the technical recommendations and the requirements of SNIP. Roof lathing and counter lathing are one of the most important elements on which the reliability and quality of the equipped roof depend in the future.

One of them serves as the basis for mounting the roofing material and creates a gap between the latter and the insulation layer, and with the help of the other, additional ventilation ducts are created for the under-roof space. Therefore, the question "how to make a roof crate" does not lose its relevance. In fact, this structure, laid out from a number of boards nailed to the truss system, is an "intermediary" between the roofing and enclosing structures. Among other things, through it, the load of the roof is evenly distributed over the supporting frame.

Types of battens depending on the roofing material

Lathing (formwork) are of two types:
- sparse -used more often for sheet corrugated material, the minimum distance between the purlins is 40–50 mm. As a material, a beam is used for lathing with a section of 50 by 40–50 or boards: width 10–20 cm, thickness - 2.5–3 cm.
- continuous- are made of tongue-and-groove boards (2.5x10 cm), and now more often from moisture-resistant plywood or OSB3, with a gap between the parts of 1 cm. This type is mainly used for piece roofing materials.
As a rule, solid formwork is performed as follows. They mount a sparse one and make a second layer of formwork on it. There are two options available here:
- they are stuffed on a sparse formwork, laying dry boards one to another (preferably tongue-and-groove). They should be located at an angle of 45 ° in relation to the first layer - sparse formwork;
- on the first - sheet materials are attached, such as moisture-resistant plywood.
Thus, in order to lay the roof, it is necessary to make a special frame: first, repeating the pattern of the rafters, they mount the counter-lattice, after which, already across them, the frame itself is nailed, on which the roofing is laid.

The structure of the frame is determined by the type of roof. For example, in the case of metal tiles for installation, bars with a square section (□ 50, □ 60) are used, which are laid with a certain step. At the same time, a solid flooring is performed under bituminous tiles or roll coating using waterproof plywood or thin boards.

These structural elements make it possible to make the roof covering of the selected material continuous and ensure the strength of the roof structure.

How to make a roof sheathing, which board to use and how to fix it

The installation of the frame under the flooring is carried out from materials such as: timber, plywood, boards (better tongue-and-groove), tesa (in the case of a solid version). When choosing lumber, it must be at least second grade and without a single knot. It is not recommended to use unedged boards or timber, as this may affect the quality of the future roof structure. In extreme cases, their edges will need to be cut off.

To avoid warping, the maximum width of the board should be 150 mm - using too wide can cause damage to the roof.

If the lumber is not dry enough, over time the wood will dry out and the fasteners will loosen. All wooden elements of the supporting structure must undergo mandatory antiseptic treatment, which will protect them from damage by pests and decay.

There is no such frame only in houses with flat roofs; for pitched roofs, such a design is required. At the same time, the steeper the slope, the, say, the crate of a gable roof, has a smaller pitch.

For normal operation and durability of the roof structure, it is necessary to provide a specific humidity regime. Since houses are usually heated, if the roof is not properly made, the warm air coming from the interior will settle in the under-roof space in the form of condensate.

The double lathing of the mansard roof practically raises the covering above the insulation layer and provides ventilation in the under-roof space. That is, the water vapor and atmospheric moisture that got there from the interior of the house can easily be blown out, and the structure will thus be protected from decay.

Double decking should not have
- gaps larger than 6 mm (if this is not the case, then the gaps are covered using strips of roofing steel);
- should not bend from the weight of a person;
- boards should be joined on the rafters and be staggered.
It is also important with what nails to nail the crate and how. They are hammered closer to the edges of the lumber, slightly sinking the caps into the wood. The length of the nails is chosen from the calculation - twice as long as the thickness of the nailed board. The consumption of nails per crate in this case is 10 pieces / m 2.