How to properly mount and lay the slate on the roof - step
A slate roof is a common technological solution that is used in the process of building every third house or production facility in our country. A significant advantage of roofing materials based on asbestos cement is a low price, which reduces the cost of building a roof by 20-30%. The roof of slate has a large mass, which gives a high load on the rafter frame. Considerable weight and fragility of asbestos-cement material must be considered during installation. In this article we will describe how to fasten slate correctly and quickly.
Types of material
Slate in German means slate, a mineral that was originally used to make this roofing. Currently, this term is called sheet material for waterproofing a roof made of asbestos cement or chrysotile cement. It is made from Portland cement, water, and asbestos or chrysotile. The above components are kneaded in the right proportion to obtain a homogeneous, thick mass, and then laid out in a form. Manufacturers produce several types of slate:
- Wave. Roofing material from wave-type asbestos cement has a wavy profile. It is produced in the form of sheets with dimensions of 850x1750 cm, 1125x1750 cm, 1130x1750 cm. The classification of wave asbestos cement divides the material according to the number of waves on the sheet surface, there may be 5.6.7 or 8. Laying slate of this type is complicated by the coating profile, which reduces it mechanical strength. Manufacturers recommend using it on roofs with a slope of more than 12 degrees.
- Flat. Unlike the wave, flat slate has an absolutely flat surface. It is also made in the form of sheets of various sizes and thicknesses. They are used for wall decoration, installation of formwork for pouring the foundation, protection from fire. However, the roof of slate flat type is also popular, as the wave. Laying such a coating is more difficult and longer, since for this purpose, sliced plates of asbestos cement with a size of 40x40 cm are used.
Correctly mounted roof of slate is considered a reliable way to protect against precipitation, cold and wind. It is highly resistant to temperature changes, UV rays, and it can withstand up to 50 freezing and thawing cycles. The advantage of the asbestos-cement coating plus is the incombustibility of this material.
Note! When purchasing slate pay attention not to the size of the sheet, and the usable surface area. Laying slate overlaps on 1-2 waves, so this figure depends on the distance between the ridges and the height of the wave. The smallest useful area has a five-wave slate, and the most economical brands - 7 and 8 wave.
Choice of fasteners
Most of the developers who install the roof of slate, in the choice of material are guided by a low price and a long service life of this coating. However, the time and effort that laying slate takes can increase total construction costs. In order not to delay installation, it is necessary to automate this process whenever possible with the help of cordless tools and high-quality fasteners. Experienced roofers recommend fixing asbestos cement sheets using the following devices:
- Nails They are considered the traditional type of fasteners, with which slate is laid. For fixation of asbestos cement sheets, galvanized steel nails are used that are not subject to corrosion. The size of the nail depends on the height of the slate wave, it varies in the range of 70-120 mm. The fastener caps have an enlarged diameter of 14 mm so that the melt and rainwater do not penetrate the hole. Rubber roofing nails are hammered into the slate trough, and galvanized - on the crest of a wave. When hammering with a hammer, it is necessary to correctly calculate the force of impact, so as not to split the lit asbestos cement.
- Roofing screws or screws. For those who want to speed up the process of laying slate with a cordless screwdriver, special screws are meant. They are made of hardened steel, supplied with a wide press washer, and then painted in various colors. The rubber head covers the hole, preventing the ingress of fluid. Roofing screws are produced for screwing a wrench or a screwdriver. Holes, the diameter of which is slightly larger than the size of the fastener, are made in the asbestos cement sheets in advance using a drill so as not to cause the sheet to crack.
Important! The fasteners are placed on the crests of the slate wave, so that no liquid can leak through the possible gaps. Experienced roofers use nails to fix asbestos-cement coatings, and self-tapping screws for bitumen, metal and plastic coatings.
Styling methods
The secret of durable and reliable slate roof in high-quality installation. Although at first glance there is nothing complicated in this process, there are a number of nuances that significantly simplify the task for roofers. Since each asbestos cement sheet weighs 25–30 kg, the first thing to do is to reinforce the sheathing of the roof truss framework and check whether it can withstand such a load. Slate is laid in several ways:
- "Scramble". This method of mounting slate implies mounting each subsequent row offset by half a sheet from the previous one. If you lay the coating in this way, the joints between the elements of the roof do not match, which has a beneficial effect on the waterproofing quality of the roof. The most convenient way of laying “scrapping” is considered the 8th wave slate. If you cut it into two parts, it turns out less unsuitable residues. The disadvantage of this method is that the end edge is uneven, without trimming it looks inaccurate.
- With trimming corners. In this method, the optimal overlap of the sheet horizontally and vertically is achieved by trimming the corners of some elements. Corners are cut so that there are no places, with a four-fold layering of asbestos cement. The method of laying slate with cropping is considered more economical. However, it is usually performed by professional roofers due to the complexity and the large number of harsh ones.
Manufacturers and professional roofing masters strongly recommend using respirators and face masks when working, and especially when cutting, slate. These personal protective equipment will save from contact with asbestos dust, which, penetrating into the respiratory tract, cause irreparable harm to human health. In order for the process of releasing a dangerous mineral during cutting to occur not so intensively, it is necessary to wet the place of processing with a damp cloth.
