Asbestos-cement sheet, better known under the name slate, has not lost the glory of a unique building material for many decades, successfully applied in modern construction.
Application area
Slate sheets today are made in two versions - wave and flat.
But if a profile corrugated sheet is used only as a roofing, then flat finds much wider application.
It is used in the construction of residential buildings, as well as administrative and industrial facilities. In this case, an asbestos-cement sheet is used as a fixed foundation formwork, used for the construction of unloaded partitions in a building, as one of the components of a flat roof cake, dry screed for floors or as a fence for balconies and loggias.
In the manufacture of sandwich panels, slate is a facing component.
In agriculture, it is used for the construction of fences, cattle pens, cages in poultry farms.
Types of asbestos-cement sheets
Slate is a mixture of asbestos fiber, Portland cement and water. Evenly distributed in the total mass of the composition, it is asbestos that creates the reinforcing base, which gives the sheets impact strength and tensile strength.
Depending on the production technology, asbestos-cement sheet is produced unpressed and pressed. The pressing method makes it possible to significantly improve its operational characteristics, due to which the strength increases and the porosity decreases.
Since the unpressed slate has lower strength and a 2 times smaller defrost-freeze cycle than its pressed counterpart, it is used only inside buildings.
Both types of slate are not expensive, and unpressed asbestos cement sheet is much cheaper.
Advantages and disadvantages
It is no coincidence that this building material is in great demand. It is distinguished by high technical characteristics, the main of which are:
- frost resistance and ability to tolerate temperature extremes;
- lack of deformation during heating;
- high strength;
- good sound insulation;
- ultraviolet indifference;
- high fire safety;
- the ability not to accumulate static electricity and not to shield electromagnetic fields;
- high anticorrosive properties;
- resistance to rot and mold;
- ease of processing and ease of installation;
- durability.
Such properties have all kinds of slate. Along with this, the flat pressed asbestos cement sheet has even better qualities:
- twice the ability to withstand temperature changes;
- higher margin of safety;
- very low porosity.
Thanks to the latter property, its water absorption is reduced, and the leaf successfully resists the appearance of moss on its surface.
The durability of 30 years, which is inherent in an unpressed slate, increases to 40–45 years.
One of the main disadvantages is the relative fragility of the sheets, which requires increased attention during transportation and installation.
In addition, they include:
- the severity of the sheets, which makes it impossible to stack them alone;
- the need for processing cutting tools to cover sections with special compounds;
- the tendency (over time) to the appearance of moss.
Protection needed
To increase the service life and maintain operational characteristics, all types of slate need additional coloring. Due to this, over time, the sheets practically do not collapse, the release of asbestos particles into the air decreases, the level of water absorption decreases, which increases frost resistance, and a barrier is created for the growth of lichens and mosses.
Asbestos cement sheet (slate) is treated with special acrylic paints. They not only create a protective film on its surface, due to which the service life is increased by 2 times, but also give it an aesthetic appearance.
Mounting Features
Before you start laying slate on the roof or wall covering, you need to purchase a respirator. It will prevent the ingress of dust into the airways, which is formed when cutting sheets.
You should also be aware that all sections should be immediately treated with acrylic paint.
Before starting installation, asbestos-cement sheets are scanned, sorting broken ones and those that have chips.
The nails used for fastening the sheets must be equipped with a galvanized hat and a rubber washer. They can’t be scored right away. First, holes must be drilled under them in the slate, then carefully using the hammer to begin the fastening process.
In the process of laying, in order not to damage the sheets, you can not walk on them. For movements you need to use special ladders or walkways.
If you adhere to the above recommendations, it will be much easier to install asbestos cement sheets. We hope you find our tips helpful.