An important element of the roof for the integrity and durability of the future roof is the crate - the foundation and guarantee of your peace of mind with its correct and reliable fastening. In order to make a crate for a metal tile, you need to learn theoretical skills, the practical use of which will allow your roof to serve for many years.
The device and types of crates
Before making a crate for a metal tile, it is necessary to find out the type of future flooring, which can be solid or lattice. The device of the crate for the metal tile directly depends on the wavelength of the future profile. In the case of using a continuous crate, edged boards with a size of 32 × 100 mm or bars with a section of 50 × 50 mm are used. Boards or beams are placed almost close to each other, at a distance of 10 mm, to ensure the necessary ventilation of the under-roof space.
If grating is used, then the installation of the crate under the metal tile is somewhat more complicated, but at the same time the consumption of materials is reduced, which leads to cost savings and lightening the total weight of the roof.
Before starting the fastening, it is necessary to treat the slats (bars) with an antiseptic, which will ensure their long service life!
Dimensional features of the crate
The main dimensions of the crate under the metal tile are its pitch, as well as the size of the boards used. The step is determined by the wavelength of the metal tile and has a specific value, which depends on the type of profile used. The hardest place in the profile is located at the bottom of the wave, before the start of the next one. Therefore, the crate occurs precisely in these places.
Manufacturers produce profiles with different wavelengths (although there are basic wavelength sizes), which causes a different pitch of the future carrier system for a specific type of metal tile purchased.
For simple and lightweight structures, with a small wave height of the roof, and a sheet thickness of 0.4-0.45 mm, edged boards with a section of 25 × 100 mm are used. A board with a section of 32×100 mm is suitable for structurally complex roofs, as well as when using metal tiles with a large wave height and a sheet thickness of 0.5 mm. In both options, a rafter step of the order of 0.6-0.9 m is used.
Bars with sections of 40 × 60 mm or 50 × 50 mm are mounted with a large rafter pitch (more than 1 meter) and, as a rule, rarely.
There are three main types of profile with different wavelengths. The main manufactured standard sizes of metal tiles have a wavelength of 300, 350 and 400 mm. Accordingly, the step is determined by the wavelength of the profile. The interval, which is equal to the pitch of the crate, is measured from the centers of the boards. Based on these data, the calculation of the crate for the metal tile is carried out.
Installation and fastening of the crate
For fastening, nails with a diameter of 3-3.5 mm are used, twice the length of the installed thickness of the board (or timber). The board for the crate under the metal tile is fastened with two nails along the edges, which are hammered as close as possible to the axis of the rafters.
Before starting installation, special attention must be paid to fastening the first row of boards located at the eaves. All profile sheets will be aligned along this row, so special attention must be paid to the accuracy of marking and fastening. The thickness of the bottom board must be at least 10 mm larger (the exact size must be obtained from the profile supplier) of all other rails, in order to level the difference in the reference points of the profile sheet. To ensure the drop, an extension of the slats of the required thickness is used, either along the entire length of the first row, or inserts are placed on each rafter.
The step size between the first two wooden slats should be smaller than the rest. This value is measured from the edge of the frontal board to the middle of the second board and its calculation depends on the length of the protrusion of the edge of the sheet and the angle of the roof slope. Also, this value is affected by the diameter of the installed drainage system. Most often, this size is standard and its possible values \u200b\u200bare indicated in the table, in the figure below.
Before fastening the first two boards, to check the correct distance between them, you can use two trimmings and bait them on the counter-lattice. A profile sheet is laid on the trimmings and a sufficient protrusion of the metal tile for normal water flow is established empirically.
Incorrectly installed crate for metal tiles can lead to the following flaws:
- if you make the protrusion more than necessary, then the water will not fall into the groove of the gutter, but will overflow through it;
- a smaller protrusion can lead to water ingress between the gutter and the frontal bar;
- insufficiently strong fastening to the crate;
- inconsistency of profile sheets;
- difficulties in attaching the end and gable strips.
The waterproofing film is passed through the extreme bar into the drain. To protect it from tearing, the upper edge of the board is made bevelled, at an angle of 120-140 °, relative to the end of the rafter leg.
When attaching the outer end boards of the gable, it is necessary that they protrude above the purlin to the height of the roof profile. This size depends on the type of profile used and is in the range of 28-58 mm.
After attaching 3-4 rows of boards, structural elements can be placed on the roof slope and taken from there for further use - this provides obvious convenience.
To fasten the ridge, one additional board is used on each roof slope, at the points of its connection with the structure. The dimensions of the boards are the same as for the installation of the crate.
The roof is a mandatory structure that is present in any home. It not only protects the living space from winds and precipitation, but also makes the building more attractive and complete. In such a design, one of the most important roles is played by a properly built crate.
Description
Currently, the choice of roofing materials is very rich, so you can choose the best option for every taste and budget. In order for the coatings to lie correctly and reliably on the base, it is necessary to install a strong and durable crate. This design will extend the life of the roof and make it more wear-resistant.
The crate itself is a perpendicularly laid beams. These parts are installed on the rafter legs. This design assumes the main load from the roofing material. In this case, the rafters transfer the weight of the roof to the floors. Properly executed, a reliable system is obtained that lasts for many years.
Another important component of the roofing "pie" is the counter-lattice. This design differs from the crate in its functions and structure, but not everyone knows what it is.
The counter-lattice also consists of wooden bars. They are stuffed directly on the waterproofing material, on the rafters. This design is mounted to form a high-quality waterproofing layer. As a rule, the counter-lattice is installed under the metal tile.
The crate and counter-lattice under the roof are made from various materials.
Best for this kind of work:
- grooved board;
- unedged board;
- edged board;
- high-quality plywood, resistant to moisture;
- chipboard.
Experts do not recommend making such structures from boards whose width is more than 15 cm. This is due to the fact that over time, such a building material begins to warp. Such defects are especially susceptible to areas located across the fibers.
Installation of such structures is quite possible to do it yourself. Of course, this work cannot be called very simple and fast. The reliability and durability of the roofing material will directly depend on the quality of the crate you have built. That is why the installation of such systems should be treated as responsibly and seriously as possible. If you doubt your abilities, then it is better not to take risks, but to entrust the work to professionals.
Kinds
There are two main types of battens for roofing material. They are solid and sparse. Let's take a closer look at these structures.
solid
A solid type of crate is installed using moisture-resistant plywood or OSB sheets (their thickness should be at least 10 mm). Sometimes boards are used to assemble this structure. If you use the latter material, then you should take into account that it fits with small gaps (approximately 10 mm).
The main advantage of a continuous crate made of sheet material, of course, is the perfectly flat surface that results. On such a design, there are no differences, unlike options assembled from boards.
However, such a system also has several disadvantages.
- Laying sheet battens can be a big blow to the wallet, as OSB or plywood boards tend to cost more than regular boards.
- Dense laying of tiles on the crate is not always something positive. The increased thermal conductivity of the roof will certainly provoke the appearance of condensate, even if the temperature values \u200b\u200bfluctuate during the day. With dense laying, there is no ventilation gap left to evaporate excess moisture, so it will constantly accumulate under the roofing material, which is very harmful for it.
- If you think about how the metal tile is laid on such a base, it becomes clear that there is little point in it in principle. For flexible tiles, a solid crate is an excellent option, but for metal tiles it is quite acceptable to use more affordable designs.
Solid lathing, made of boards installed with a small gap, is best suited for installation at small angles of roof steepness when laying corrugated board, slate or roofing from a material such as ondulin. As for the metal tile, it is not recommended to use a crate of boards for it.
sparse
The sparse crate under the roof is recognized as the optimal design. When installing it, the guides must be installed so that the sole of each horizontal row of metal tile modules acquires a reliable lower support and a sufficient width of the material for installing self-tapping screws.
In this case, the gap between the axes of the horizontal guides, must necessarily correspond to the longitudinal length of the modules of the roofing material. Most often, the step between the bars is several centimeters. This design is well suited for metal roofing, corrugated slate and tiles of natural origin.
For the construction of a sparse roof, it is permissible to use boards with a thickness of 20-40 mm. At the same time, the dimensions of the bars can be 50x50 mm or 60x60 mm, and the diameter of the pole is 70 mm.
In this case, the choice of a suitable material for the manufacture of battens largely depends on the roof and its features. For example, a tree used in construction must be at least grade 2 - knots and other defects should not be present on the material. It is advisable to choose a cutting board.
If an unedged board is used in the manufacture of a sparse crate, then its edges must be bevelled. Materials whose width exceeds 140 mm are not recommended to be purchased - such boards may deform over time.
When creating a sparse crate structure, it is necessary to choose a material:
- on which there are no knots - such defects often lead to breakage of boards under the weight of snowfall;
- dry wood - in no case should wood be damp, because over time it will dry out anyway, and fasteners (nails or self-tapping screws) will not hold so tightly in the material.
Very often, a flat solid crate is laid on top of a sparse one. Of course, such a device is not mandatory. It is quite permissible to mount a solid structure without first erecting a sparse base.
Material selection
As mentioned above, various materials can be used to construct the roof battens. The main condition for the choice is their ideal quality. Only with the use of reliable and durable bars over time, sagging or bumps will not appear on the structure. In addition, the flooring itself must be strong enough not to bend under the weight of an adult.
You should also pay attention to the size of the nails that you are going to use when installing the crate. To calculate this indicator, it is necessary to ensure that the length of one nail is not less than twice the thickness of the nailed board.
It has already been said above that the type of counter beam and the main lathing, first of all, depend on the material from which the roof is made. For example, under sufficiently rigid coatings, such as metal profiles, tiles or slate, you can use a sparse structure made of boards.
The most popular roofing materials are:
- ceramic, cement-sand or polymer-cement tiles;
- slate or special euroslate;
- false materials;
- metal tile;
- soft or flexible roofing.
Most varieties of tiles (with the exception of metal) are small piece elements. Such materials are of the highest quality and easy to install due to the many positive properties and long service life.
The heaviest materials are recognized as tiles. For this reason, they must be laid on the most durable and strong crate and base. For this, it is recommended to use solid bars with a cross section of 50-60 mm.
One of the most common roofing materials is slate. The main advantage, due to which many consumers choose such coatings, is that they are compact in size, so they can be easily laid on bars, the dimensions of which are no more than 50 mm. During the installation of larger slate sheets, it is permissible to use batten elements with a thickness of about 80 mm. The step in this case directly depends on the dimensional values.
Large sheets of slate should be installed in such a way that there are at least three supports under them. This condition must be observed so that such a roof begins to sag over time under the influence of its weight and precipitation.
Seam roofing is not so popular at present, but sometimes it is still used in the design of the roof. Its slope, as a rule, is within 14 degrees. As for the configuration of such a roof, it is quite complex and intricate, so experts strongly recommend installing it on solid types of crates.
More simple and undemanding in terms of installation is a flexible roof. However, its installation requires a one- or two-layer continuous crate. The weight of these building materials is small, so it is not so difficult and energy-consuming to install them.
Now let's take a closer look at which lathing step is suitable for certain types of roofing materials:
- Flexible roll coverings should be mounted on a solid base. The step between its individual components should not exceed 10 mm.
- For a roofing material such as slate, the step should be selected in accordance with its dimensions. This indicator mainly depends on the thickness of the sheets, which can be 50-75 cm.
- As for the metal tile, the sheathing pitch for it, as a rule, varies from 300 to 400 mm. The gap between the last two bars should be 2 times smaller.
- When laying any type of tile, it is necessary to rely on the manufacturer's instructions, while remembering the degree of roof slope. Often in such a case, the boards are installed at intervals of 320-380 mm.
- For a seam roof, the most common frame pitch is 200 mm.
Calculations
Before proceeding directly to the installation of a high-quality and reliable crate, it is necessary to make all the calculations, since they cannot be dispensed with in construction.
- roof size;
- type and thickness of the laid material;
- roofing structure.
If it seems to you that drafting a future structure on your own is a very difficult task, then you can use a special online calculator that will quickly automatically determine all the necessary parameters.
How to prepare?
Installation of the crate under the roofing material is quite possible to do it yourself. To get started, stock up on all the necessary tools and fasteners, which include:
- nails and hammer;
- screws and screwdriver;
- a hacksaw (instead of it you can buy a grinder - it will be more convenient to work with it);
- pliers;
- a special pencil or chalk for marking;
- roulette;
- bubble or laser building level.
When you have acquired all the tools and materials, you can proceed to the preparatory work. You should not neglect them, otherwise, as a result, the design may turn out to be unsteady and short-lived, and it will be very difficult to put it up.
Stages of work.
- First, carefully measure the roof. Then you should start preparing the boards for the manufacture of the frame structure.
- If the roofing material has an impressive weight, then it is better to use wide edged boards. Such details will easily withstand the heavy weight of the roof.
- Experts also recommend sorting building material. This is due to the fact that in many batches there is a substandard, which is thinner or thicker. The use of elements of different sizes often leads to the fact that the roof is laid with bumps and bumps.
- If you want to additionally insulate the attic space, then before installing the batten and roof, you need to lay a special anti-condensation film on the base. Fastening of this material should be done directly to the rafters. The film must be mounted in horizontal stripes. In this case, an overlap of at least 10-15 cm should be made. No need to stretch the film - it should sag slightly between the rafters. It is recommended to fasten such material using bars with a thickness of not more than 3 cm.
- In addition, it is necessary to calculate the pitch of the crate before proceeding to its installation. It is determined depending on the dimensions of the roof. For example, to install a popular metal tile, the best place is the bottom of the wave. In the area where one wave ends and the next begins, you need to screw in the self-tapping screw. In the same place, you need to further install a board or timber.
Please note that each manufacturer produces metal tiles with their own depth parameter. This indicator, first of all, depends on the height of the profile. For this reason, before starting the installation of the crate, it is necessary to clarify the wavelength of the material.
Installation Guide
Upon completion of all preparatory work, you can proceed directly to the installation of the crate under the roofing material. Consider a step-by-step installation guide using the example of a crate for a metal tile.
First, for the rafters, you need to choose the right bars. Their size must be at least 50x100 mm to create a crate with a cross section of at least 25x100 mm. As for the counter-lattice, it can be made from a 25x50 mm board. As a rule, in this case, the pitch of the rafters is 600-900 mm.
Along the overhang of the cornice, the starting board should be nailed. But it should be noted that it should not go beyond the overhang itself. To even out the difference in levels, this board should be a little thicker than the others (no more than 1.5 cm). The gap between the board extending beyond the eaves should be 50 cm less than the step between the other elements.
To make sure that this distance is maintained correctly, you need to lay out two pieces of board on the ground, and then put a piece of tile on it. This way you will be able to determine whether there will be enough of the existing ledge for sufficient water flow. If the protrusion is larger than necessary, water will overflow through the gutter.
If the protrusion is too small, then excess water will simply fall into the space between the gutter and the frontal board. In addition, if there is too long a protrusion, the sheets may deform over time due to a significant load from snow.
After marking, you need to fix the ridge and end strips. At the same time, the wind board must be attached higher than the crate itself (approximately the width of one sheet of metal tile - 35-55 cm).
To fix the skate firmly and reliably enough, additional boards with a size of 25x100 mm must be nailed to the connection areas. With these details, further installation will be a little easier.
If you want to install a drain before laying the roof, then you need to mount the brackets to which the gutters will be attached. These elements should be installed on the bottom board, maintaining a step of 500-600 mm.
First, the end brackets are installed so as to calculate the slope of the gutter per 1 m of length. After that, you need to stretch the cord along which the rest of the brackets will be installed.
Also, before the start of direct flooring, a cornice strip should be installed. The gutter should also be mounted on brackets. As for the cornice strip, it should be placed so that its edge, located at the bottom, overlaps the edge of the gutter.
In places where there are various joints, for example, pipes or attic windows, a solid type crate should be installed. In this case, preference should be given to even and high-quality boards made of wood or wood-shaving raw materials.
Only after completing all the listed works, following all the rules, you can lay the metal tile.
You should know the following nuances:
- The correct calculation of the required volume of materials, as well as the choice of the crate step, directly determines how reliably and firmly the roof will hold. In order not to make a mistake anywhere, experts recommend using special online calculators.
- In places of joints and slopes, it is recommended to install a continuous crate. Otherwise, when installing additional elements, the screws may be in the void.
- To attach the material faster, you can prepare a wooden step template in advance.
- If in the manufacture of the crate you use sheets having a height of less than 35 mm, then you should make the step minimal. Thus, you will make the roofing material stronger and more rigid.
In the joints located horizontally, it is recommended to make small offsets. They are needed so that over time the structure does not weaken, and also does not require the replacement of certain components of the structure.
- As a waterproofing membrane, it is permissible to lay almost any dense film that does not allow water to pass through. If you are going to make the roof insulated, then you should turn to a special diffuse membrane. It does not retain water vapor from the thermal insulation layer.
- During installation work, nails and self-tapping screws are most often used. Fasteners must be as reliable and of high quality as the rest of the components in the entire structure.
- Make sure that there are no nail heads on the base under the roof. Please note that damaged parts cannot be bent - they must be removed from the material and new ones driven in. This nuance is especially important if you are going to lay a soft roof or roll covering on the frame.
- The gap between the boards with a solid structure should not exceed 1 cm - be sure to follow this.
- For the manufacture of a system such as a counter beam, it is recommended to use thinner bars that need to be stuffed onto the rafters above the waterproofing layer. At the same time, it should be ensured that sufficient ventilation gap remains in the structure.
The construction of the foundation for the roofing is considered the smallest part of the work in the list of major construction activities. The foundation, the construction of walls and partitions usually require a lot of effort and material investment. Nevertheless, the roof is the most important component in the design of any building, so the implementation of this measure should be approached responsibly. Loads in the form of precipitation, gusts of wind and other mechanical influences can violate the tightness and integrity of the roof. Therefore, you should carefully approach the creation of the foundation on which the roof will be fixed in the future. The installation of rafters and battens is considered by experts as the most significant stage on which the reliability of the roofing depends. There are different approaches to the installation of this part of the structure, the choice of which is largely determined by the characteristics of the final flooring.
Installation of the rafter system
Even a well-installed crate will not provide the necessary supporting function if it was installed on a weak one. Therefore, it is important to mount it correctly.
First of all, the Mauerlat is attached - beams that will act as the basis for the sections of the structure. The best option involves the use of a one-piece Mauerlat, fixed. Next, they fix it to the installed elements. Then you can start assembling the sections. The choice of the configuration of their location and attachment to each other is determined by what the installation of the roof lathing of the house will be.
Based on the general plan, a drawing is drawn up, after which the structure is assembled on the ground. The finished system must be lifted to the roof - usually this is done by means of a winch. When one of the sides is maximally pressed against the base of the building, it can be released from the cables and fixed with ties and crossbars. The basis of the fastening will be the corners with bolts, which will allow you to securely fasten the rafters to the Mauerlat.
Roof membrane installation
A common mistake many inexperienced roofers make is to ignore insulation measures. The tightness of the roof, the absence of dampness in the attic and the general comfort in the premises depend on the quality of this stage. After installing the rafters, you can start laying the appropriate protective materials. Regardless of the technique by which the crate will be installed, the structure can be insulated in the lower part with the help of this layer. This layer will provide vapor permeability and waterproofing. But it may not be the only roofing material - sometimes membranes are supplemented with insulation. The very process of laying such a coating is not particularly difficult. The membrane is delivered in the form of rolls, which are spread at the workplace and laid over the entire area of the rafters. The strips can be laid overlapping, and fixing can be done with glue or special hardware.
The nuances of choosing wood for crates
The selection of materials for the supporting structure under the roof should be approached carefully, and this is especially true for wood. It is desirable that the installation of the crate is made of coniferous material, for example, spruce and pine. This is an easy-to-work tree that will provide flexibility and strength during the life of the roof. It is also important to consider the type of material. Of course, the first category would be the ideal choice, but if financial possibilities exclude such an acquisition, then you can limit yourself to the second grade. However, such structural elements should first be treated with antiseptics.
Another significant parameter of choice is humidity. If the inside is supposed to be protected in the form of a plasterboard coating, then wood with a moisture content of not more than 20% can be used. If it is planned to install a crate, part of which will have direct access to air, then the use of wood with a moisture content of more than 20% is not excluded.
Installing siding under siding
For the installation of siding panels, it is worth preferring a wooden crate. This choice is justified by the flexibility of the material, which will not allow the outer coating to deform. In the process of installing the elements, it is important to maintain uniformity, that is, all the rails must be in the same plane. The fastening itself is carried out with hanging brackets or ordinary nails. If the base has irregularities, then you can adjust the position of the frame using wedges. As a rule, the installation of the crate for siding is carried out with an element step of 20-30 cm. But in each case, this distance should be calculated individually. The larger the working area, the longer the indent - this is the main rule that roofers are guided by in such a design.
Installation of the crate under the metal tile
The complexity of the frame arrangement for metal tiles is due to the fact that profiles can have different corrugations and sizes. By the way, siding in this sense is more standardized. If a continuous crate is planned, then it is better to use boards with parameters of 3.2 x 10 cm or bars of 5 x 5 cm. Fixation is carried out close to the base in increments of 10 cm. . Accordingly, the installation of the crate under the metal tile must take into account the high loads on the structure. For fastening, you can use nails 3 mm thick, while their length should be twice the cross section of the board. A feature of the installation of the frame under the metal tile is the wide presence of metal fittings for fasteners. Various brackets and corners, acting as an additional means of fastening, are most common in roofs of a large area. If a standard gable system is planned for a small house, then it is quite possible to get by with slats, which are fastened with frequent steps with nails.
Installing a sheathing under a soft roof
The device of a soft roof can be called the most demanding and even capricious type of such work. This material is laid on a flat solid flooring, so the crate will be carried out in two stages. First of all, the frame is mounted. Its features will be the frequent step of the rails and the utmost accuracy. Next, a smooth protective coating is formed, on which a soft roof will subsequently lie. If the installation of the roof batten can be carried out using the same bars and battens, then chipboard, plywood or other wood-based material with similar characteristics should be used as additional flooring. The main thing is that initially the design of the rafters is well insulated. In addition, the ends of the base must be rounded to ensure a smooth transition of the decorative roof.
Features of the installation of plastic crates
Usually, metal is considered as an alternative material for the lathing device. Wood does not always achieve the required strength, so it is replaced with profile elements. However, in some cases, a plastic crate is also acceptable, the installation of which involves some differences, but in general the attachment technique remains the same. Fixation is carried out through special holes in the elements using bolts or self-tapping screws. But the peculiarity of plastic panels for the crate is that their design allows for more reliable attachment to the rafters using a groove system. There are different models of such elements that should be selected specifically for the needs of a particular roof.
Installing the counter grille
By design, this type of crate is in many ways reminiscent of a traditional frame formed by slats or boards. Its fundamental difference lies in the additional strengthening of the system due to insulation with roofing material. It has already been noted that the design should provide for the presence of a heater and a vapor-tight membrane. But in this case, the function of protective roof barriers is enhanced. That is, first roofing material or other material with similar properties is laid, and then the installation of the crate on the rafters on top of the insulating deck. The configuration of the arrangement of elements can be either sparse or solid. The main thing is to provide sufficient space under the roof to prevent the formation of condensate. This is especially important when fixing which accumulated moisture acts destructively.
Conclusion
A variety of materials for creating roofing determines the requirements for both the truss system and the supporting frame. In turn, the installation of the crate cannot be carried out without taking into account the operational requirements for the final coating. For example, metal decks require a higher degree of structural reinforcement. In this case, it is important to provide high-quality material for creating the crate that can withstand weathering. For siding, on the contrary, physical strength is not so important, and the flexibility of the frame comes to the fore, which is ensured by properly selected rails.
At the initial stage of building a house, the design of the roof and the type of material to cover it are chosen. You need to know how to properly make a crate for a metal tile, and then the roofing pie will perform its function qualitatively and thereby make living in the house comfortable.
A popular choice for roof construction is pre-painted galvanized metal sheet, which is designed with different profiles. This is explained by reliability, durability, low price of the material and minimal maintenance. It is not difficult to make a roofing cake, but there are a number of nuances in such work, including following the instructions from the manufacturer on how to lay the crate under the metal tile.
Construction of the truss system
The basis of the roofing cake is the rafter system. Its correctly performed calculation will guarantee long-term operation of the roof and reliable protection of housing from natural phenomena.
When carrying out low-rise construction of buildings, one of the following types of roofing structures is used:
- lean-to;
- gable;
- four-slope (hip);
- attic;
- multi-forceps;
- half-hip (two-slope);
- tent.
Regardless of the features of the structural design of the roof, the rules for choosing building materials, or rather, timber, are similar. Given the length of the rafters, determine the distance between them and the size of the section of lumber.
The presence of a heat-insulated roofing cake allows you to use the attic, including in cold weather. Now the arrangement of attics is very common, therefore, at the stage of roof construction, it is necessary to reliably isolate the insulation. For these purposes, special waterproofing membranes and barriers are used.
The main functional purpose of these materials is to collect moisture that condenses on the surface of metal sheets. Without their use, water will begin to be absorbed in the insulation, and this leads to a decrease, or even loss of its thermal insulation qualities. Waterproofing is attached to the rafters with brackets.
To improve the fastening of the film and arrange a ventilation gap between the roofing and the film, it is necessary to fill the counter-batten. The bars and the step of the board under the metal tile are selected taking into account the width of the rafters and the length of the roof slope.
SNiP P-26-76 regulates that for roofs with a slope length of less than 6 meters, a bar with a section of 30x50 millimeters should be used. For multi-pitched roofs, in which this parameter exceeds 6 meters, the thickness of the bar for the counter-lattice should be 50 millimeters. In order to improve the ventilation of the space under the roof, special holes are also made - vents along the entire length of the slope.
Materials for lathing under metal roofing
The base for the metal tile is made of softwood lumber. As a rule, choose a pine board. Its thickness depends on the angle of inclination of the slopes, as well as the installation step of the rafter system and the average annual snow cover in a particular climatic zone. Note that the board for the roof sheathing must be of high quality, without damage.
In places where the arrangement of such additional elements for the roof as snow guards, safety elements, stairs, running ladders is required, it is necessary to strengthen the formwork for metal tiles by installing support boards.
To create a crate for metal coating, moisture-resistant plywood in sheets or OSB is often used, and the crate of boards is mounted solid. This circumstance helps to increase the reliability of the roofing pie and create additional insulation, but at the same time it increases the load on the structure, increases the consumption of materials and the cost of building a roof.
In order to compensate for the linear expansion of wood, in conditions of a constantly changing level of humidity, there is a rule with which step to make a crate for a metal tile from sheet materials - you need to leave a gap of 3-5 millimeters between the elements. The laying of sheets is shifted relative to the initial row up to half of the product to increase the strength of the truss structure.
To reduce costs and reduce the weight of the roof, an option such as a discharged crate is used.
Lathing step and distance
Manufacturers of metal tiles produce sheets with three main wave pitch sizes - 300, 350 and 400 millimeters. Sometimes there are products with a wavelength of 150 and 450 millimeters. They are used infrequently, but the basic rules for laying a crate under a metal tile are the same.
For mounting a sparse version of the base under the roof covering, edged boards are used. When a crate is created for a metal tile, their thickness should be 20-35, and the width 100-150 millimeters. Most boards are cut tangentially, so in order to avoid distortions during their installation, it is necessary to ensure that the annual rings are located to the rafters and the counter-lattice.
Before you nail the crate under the metal tile to each of the rafter legs, you need to stock up on nails and self-tapping screws. Fix the boards from both edges. As for the task of creating a base for a metal tile, it is not difficult. But in this case, accuracy is required.
Which is chosen for the installation of base elements, is determined taking into account the wave step on the roofing material. To complete the installation faster, before you beat the crate under the metal tile, you need to prepare a home-made template, the size of which depends on the wavelength and width of the boards used. These devices may differ in design, but it is necessary that a gap be observed between the laths of the crate.
Eaves overhang device
First of all, you need to build up the first of the laths of the crate, additionally fixing a board with a thickness of 15–20 millimeters on it, which will ensure rigid fixation of the coating material - it will not sag.
For stone buildings, the size of the roof overhang should not be less than 450 millimeters, and for wooden houses - 600 millimeters. When the rafter cannot provide the desired overhang length, it is built up using a filly. Be sure to install the end board.
To ensure the collection of condensate and a sufficient degree of ventilation of the under-roof space, a drip is mounted, beyond which the edge of the waterproofing material is taken out. The membrane is attached to the dropper with self-adhesive tape.
The drainage structure begins to be installed before the installation of the metal tile:
- Above the rafters or on the starting board of the crate, holders for the gutters of the system are attached with a step of 60-80 centimeters and a slope of the gutter, based on 3-5 millimeters per linear meter.
- The gutter must be installed immediately, since a cornice strip is lowered into it, which is fixed to the bottom board of the crate. The bottom edge of this plank should overlap the top of the gutter.
- After the installation of the fine-mesh insect net, the preparatory work on the eaves is considered completed.
How to do the crate of the valley
Improper installation of the valley leads to roof leakage and, as a result, to expensive repairs. In this case, the counter-lattice is mounted so that there are holes for the movement of condensate and small debris.
A waterproofing membrane is additionally placed on the valley, its crate is reinforced with slats.
Mounting the skate
Roof slopes intersect at the location of the ridge. It is entrusted with the function of ventilation of the under-roof space. To improve ventilation, ventilation valves can be placed on the roof slope. To fix the elements of the ridge on the rafters, you need to nail an additional element of the crate.
The roof is one of the main elements of the appearance of the building. When installing roofing, it is of great importance to observe the distance of the crate under the metal tile, which is a modern material. Simplicity and speed of installation have made this type of roofing the market leader.
Building a house involves solving many technical problems and making rational and necessary decisions. The arrangement of the roofing pie and the choice of roofing material crown the initial stage of construction.
The expedient use of the living space of the house implies the use of under-roof space with the arrangement of the attic floor.
Reliability, durability, minimal maintenance, low price - these are the main qualities that roofing material must meet. Such a material is a galvanized sheet coated with a polymer coating. Elegance and design are given to it by various profiles, including the profile of a metal tile.
The roofing pie under the metal tile is simple in its construction, but still there are some pitfalls, let's look at them.
truss system
The basis of the roofing pie is the truss system. The correct calculation of the truss system guarantees long-term operation of the roof, provides reliable protection for the home.
In low-rise construction, several configurations of roofing systems are distinguished:
- lean-to;
- gable;
- hip (four-slope);
- tent;
- half-hip (two-slope);
- attic;
- multi-forceps.
Regardless of the design features of the roof, the rules for choosing rafter boards remain the same.
The data given in the table are the minimum requirements for timber and boards that will be used in the construction of the truss system.
Installation of waterproofing and counter-lattices of the truss system
The insulated pie of the roof structure allows the use of the attic even in the cold season. Arrangement of attics in the attic will not surprise anyone. Therefore, even at the stage of roof construction, reliable waterproofing of the insulation should be ensured. For this, various waterproofing barriers and membranes are used. The main reason for using such films is to collect the condensate that forms on the metal sheets of the roof. Without the use of a film, moisture will be absorbed by the insulation, which will lead to the loss of its thermal insulation properties.
Waterproofing is fixed to the rafters with staples. To improve the fastening of the film and create a ventilated gap between the film and the roofing material, a counter-lattice is stuffed. The use of a counter-lattice is mandatory.
The bars for the counter-lattice are selected based on the width of the rafters and the length of the roof slope. According to the recommendations of SNiP P-26-76, for roofs with a slope length of less than 6 m, the bar should have a section of 30x50 mm. For roofs with a slope length of more than 6 m, multi-slope complex roofs, the thickness of the counter-lattice bar is increased to 50 mm. To improve the ventilation of the under-roof space, air ducts are also installed - specialized ventilation holes along the length of the roof slope.
The choice of material and crate step
Coniferous wood is used for the device of the crate. Basically it is pine boards. The thickness of the board depends on the angle of inclination of the slope, the pitch of the truss system and the height of the snow cover in the area.
When arranging additional roof elements: snow retainers, running ladders, stairs, additional safety elements. At the installation sites, it is necessary to strengthen the crate by installing additional support boards.
Sheets of moisture-resistant plywood or OSB are also used as a crate for metal tiles, and a crate made of edged boards is mounted with a continuous flooring. This increases the reliability of the roofing cake and creates an additional insulation circuit, but in turn increases the consumption of material, the weight of the roofing cake and the cost of roofing.
To compensate for the linear expansion of the material in conditions of constantly changing humidity, the installation of the lathing from sheet materials must be carried out with a gap of 3-5 mm between the sheets. Rows of sheets must be shifted relative to the first row in the middle of the sheet, this will increase the strength of the truss system.
Avoid unnecessary costs and reduce the weight of the structure will allow the use of a sparse crate of edged boards.
Manufacturers of metal tiles use three main wave pitch sizes: 300, 350 and 400mm. At the same time, some manufacturers have sheets with a wavelength of 150-450mm. Such profiles are not often used, but the basic rules for mounting the crate remain the same.
For the installation of a sparse crate under a metal tile, edged boards with a thickness of 20-35mm and a width of 100-150mm are used. Most boards have a tangential cut. Therefore, when installing the boards, it is desirable to ensure that the annual rings are directed inward to the rafters and counter-lattices in order to avoid distortions and deformations.
Boards must be attached to each rafter leg with two nails or self-tapping screws. The fastening of the board must be carried out along the edges of the board. Stuffing a board for a crate is not a difficult task, but it requires precision execution.
The calculation of the distance between the boards is selected depending on the wave length of the metal tile. For quick installation of the crate, it is necessary to build a home-made template. The size of the product will depend on the wavelength and on the width of the boards used when stuffing the crate.
Templates may differ in their design, the main thing is that the width between the boards of the crate is exactly observed.
Installation of the cornice overhang
The first board of the crate must be increased by installing an additional board with a thickness of 15-20mm on it. This will provide a rigid fastening of the roofing material and will not allow it to sag.
The roof overhang for stone houses should be at least 450mm, for wooden houses - 600mm. If the rafter does not provide the length of the overhang, it must be increased using a filly. The filly will also provide reliable filing of the cornice overhang. Be sure to install the end board. To collect condensate and good ventilation of the under-roof space, a drip is installed. The edge of the waterproofing membrane extends beyond it. The membrane is glued to the dropper using a specialized self-adhesive tape.
Installation of the drainage system should begin before laying the sheets of metal. Gutter holders of the gutter system are attached to the first board of the crate or above the rafters with a step of 60-80 cm with the calculation of the slope of the gutter 3-5 mm per meter. It is advisable to immediately install the gutter of the drainage system, the eaves bar is lowered into it.
The cornice strip must be fixed to the bottom board of the crate. The bottom edge of the cornice strip should overlap the top of the gutter. To avoid the entry of insects into the under-roof space, a fine-mesh mesh is installed. At this stage, we can talk about the completion of the preparatory work on the cornice overhang.
Arrangement of the lathing of the valley, roof windows, chimneys
The device of the valley is the weakest point in the device of the entire roof. Incorrect installation leads to roof leaks and costly repairs to interior trim.
The valley counter grid must be mounted in such a way that there are holes for the passage of condensate and small debris. An additional sheet of waterproofing membrane is laid on the valley. The crate of the valley must be reinforced with additional boards between the boards of the step crate. The valley sheets are mounted on the installed cornice strip, if the valley starts from the cornice. The crate of the valley of the roof windows, chimneys are equipped in the same way.
Mounting the skate
The ridge is the upper horizontal edge of the entire roof, where the roof slopes intersect. It performs the main function of ventilation of the under-roof space. It is possible to improve ventilation by installing ventilation valves on the roof slope. To attach the elements of the ridge to the rafters, an additional board of the crate is nailed. In the absence of ventilation, the removal of condensate will be difficult, which will accelerate the biocontamination of the wooden structure of the roof and cause corrosion of the metal parts of the coating.
The roof is one of the main elements of the architectural ensemble. It is on her that all eyes first stop. Ancient tiled roofs delight many tourists in Western Europe. To convey the aesthetics of the tile and its beauty, the modern material - metal tile - is properly called upon. Ease and speed of installation have made this material a market leader in the roofing material segment.
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