When constructing a roof, one of the essential elements is the crate. What kind of structure is this, and what nuances should be taken into account when building it?
First of all, you need to understand what is a crate? This term in construction is understood as a construction from a set of boards or beams that are fixed to the rafters, moreover, they are located perpendicular to the rafter legs.
It is the crate that takes the direct load exerted by the roofing material, transferring it to the rafters, and then to the supporting structures.
Various materials are used for construction:
- timber;
- Boards - ordinary or tongue-and-groove;
- Tes;
- plywood.
Possible types of crates
Depending on the chosen roofing material, one of two types of crates is used, these are:
- Sparse, which can have a different spacing of elements. This type is used when laying metal, slate, ceramic tiles.
- Solid. This type is made from boards, the spacing of which does not exceed a centimeter or from plywood. This variety is chosen if the roof is supposed to be covered with soft tiles, flat slate or rolled materials. In addition, a solid crate must be installed in difficult places on the roof - at the place where the chimney pipe exits, at the intersection of the slopes (in the valleys, in the grooves, on the ridge, etc.), along the roof eaves.
According to the method of construction, the crate is divided into:
- Single layer. In this case, the elements are laid horizontally on the rafters, the boards are arranged parallel to the ridge.
- Two-layer. This option involves the creation of a second layer, laid on the first. The second layer can be formed from beams or boards, which is laid in the direction from the ridge to the overhang. Sometimes the bars are laid diagonally on the first slope.
As a rule, before laying the crate, waterproofing is laid on top of the truss system. It can be the most common roofing material or modern membrane materials. The hydrobarrier is attached to the rafters using a construction stapler.
How to build a crate for roll materials?
As already mentioned, if it is planned to use roll materials, then a continuous crate should be built. As a material for its construction, it is best to use a grooved board.
The first row of boards is placed in a discharge, and the second is formed very tightly, stuffing the boards one by one.
For the device of the second layer of the crate for metal tiles, wooden slats are used, which are laid at an angle of 45 degrees with respect to the first layer of the crate.
Building Tips:
- The boards that will be used for construction are treated with an antiseptic.
- After finishing laying the boards, make sure that the coating does not have sagging, bumps and protruding nail heads.
- The completed crate should not sag under the weight of a person who walks along the roof.
- To perform the flooring, boards with a width of 100-150 mm and a thickness of at least 250 mm are used. It is not recommended to use boards with a larger width.
- Under no circumstances should insufficiently dried material be used.
- When laying boards, it is necessary to try to place the joints of the boards on the rafters in a checkerboard pattern.
- Nails should be placed closer to the edges of the boards, and, preferably, the heads of the fastener should be sunk into the wood.
How to build a crate for laying tiles?
Consider how a crate is made for laying such a popular material as metal tiles. In this case, a frame in the form of a lattice is established.
For construction roof battens bars with a section of 50 by 50 mm are used.
The spacing of the bars is chosen depending on the type of metal tile chosen. For example, if it is planned to lay metal tiles of the Monterrey type, then the spacing of the boards should be 350 mm.
But the distance between the first two (from the eaves) boards of the crate is made smaller (200-250 mm).
Advice! If a crate is being built for a metal tile, then a solid calibrated board should be chosen as a building material.
How to build a steel roof sheathing?
Steel is a popular roofing material. Consider how to make a crate for laying this version of the roof.
In this case, it is possible to make a sparse crate from bars or boards 50 mm thick, or a solid one, which is built from boards 30 mm thick.
Steel roofing sheets are laid on a flat crate, there should not be protrusions and recesses on it, because even a slight deflection of the sheet can lead to weakening of the seam joints.
How to make a crate for soft tiles?
Under this type of roofing, an even and smooth coating is necessary, it is important to prevent the material from bending and chafing. Consider how to make a crate in this case.
Construction begins counter battens for metal roofing from the installation of a lattice frame made of bars. The second layer, which is laid on top of the assembled grid, is made of roofing plywood.
Advice! Roofing plywood must be treated with a special waterproofing mixture before laying.
How to make a crate for slate?
When using slate, you can make a single or double crate. In the first case, the boards are laid parallel to the ridge and fixed on the rafters.
If ordinary corrugated slate is used, then the spacing of the bars should be 0.5 meters, and the cross section of the used bar should be 50 by 50 mm.
Advice! When a crate for slate is being built, it must be borne in mind that each sheet must be supported by three bars. In this case, even bars in a row should be slightly thicker than odd ones. The difference in thickness should be 30 mm. In this case, it will be possible to ensure a tighter overlap of the slate sheets and a uniform load on the sheets.
conclusions
Thus, the manufacture of the crate is not a very complicated process, however, the quality of laying the roofing material depends on how competently it is carried out.
It is extremely important to choose high-quality material for construction. So, for example, if raw boards are taken, then the fastenings will soon loosen, because the boards will change in size as they dry.
And when using low quality material (with numerous knots), the constructed structure will not be able to withstand the snow load.
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