Asbestos cement sheets are a building material that is used in the process of arranging the roof of residential and non-residential buildings. Often asbestos cement is simply called slate. This material is often used in the construction and arrangement of roofs due to the presence of many advantages over other materials that can also be used to create a roof.
Asbestos cement consists of short-fiber asbestos and Portland cement in a ratio of 15% to 85%, respectively. Such material has the form of rectangular sheets with rippling in the form of waves, most often, there are about six waves on each sheet. The standard size of an asbestos cement sheet is 1.2 by 0.7 meters, with a wave height of at least 28 millimeters, and a square meter of such a sheet weighs 10-15 kilograms. To arrange the roof, the sheets are laid overlapping, while soft gaskets that have sealing properties must be laid under them. For the base of the roof, you should use a crate made of bars with a cross-section of 50 by 50 millimeters, such a crate is suitable for standard profile sheets. The crate with a cross-section of 75 by 75 millimeters is suitable for sheets with a reinforced profile and a pitch of 500-550 and 750-800 millimeters.
Varieties of asbestos cement sheets
Asbestos cement sheets are divided into several types: wavy and flat sheets. At the same time, flat sheets are divided into non-pressed and pressed sheets. Wavy sheets are used for arranging roofs on residential buildings and public buildings, as well as for outbuildings and wall fences.
Flat sheets can be used as wall panels, partitions, and slabs in the construction of floors and other buildings. In particular, this type of asbestos-cement sheets can be used in the process of finishing works, both from the outside and from the inside of buildings.
Pressed and unpressed sheets have the same external characteristics. Their main difference is in different indicators of strength and density. Pressed sheets are additionally compacted, which allows them to increase their density and improve strength.
Technical specifications
Consider the main technical characteristics of various types of asbestos-cement sheets.
The bending strength index: for pressed flat sheets is about 23 MPa, for non-pressed flat sheets-18 MPa, for sheets with seven and eight waves-16 MPa.
The density of sheets should not be less than the specified value: for non-pressed sheets, as well as sheets with seven and eight waves, this indicator is at the level of 1.6 g/cm3 , for pressed flat sheets, the indicator is at the level of 1.8 g/cm3 .
The impact strength index for pressed flat sheets is 2.5 kJ / m2, for non-pressed flat sheets this indicator is slightly less — 2.0 kJ / m2.
The residual strength of all types of asbestos-cement sheets is not less than 90%.
Pressed flat sheets of asbestos cement have the highest degree of frost resistance with a number of cycles of at least 50, for other types of asbestos cement sheets, this indicator is at the level of at least 25 cycles.
Gray sheets are most often used, but colored sheets can also be used. In order to give the leaves a certain color, use pigments.
Advantages and disadvantages of the material
Asbestos cement sheets are particularly popular among professionals, primarily due to the presence of the following advantages::
- sheets differ in hardness, while they are able to withstand the weight of a person;
- such sheets are practically not warmed up by sunlight;
- asbestos cement sheets are durable;
- sheets differ in fire safety, they are fireproof, non-combustible;
- such sheets can be easily processed with various tools;
- sheets are not subject to corrosion, in comparison with a metal roof;
- they are distinguished by the presence of excellent electrical insulation characteristics;
- during rain or hail, the sheets do not make any noise;
- low cost compared to other materials;
- excellent alkali resistance;
- it is very easy to repair such sheets, and you can replace individual sheets.
Asbestos cement sheets, like other materials, have their drawbacks:
- over time, moss may appear on the leaves, but at the moment its appearance can be prevented by using a primer that can increase the sheet’s water resistance.;
- the weight of the sheets, they are slightly heavier compared to other materials, so in order to lift them to the roof, you will need to make an effort;
- asbestos cement sheets are fragile, so they must be carefully transported and installed.
Scope of application of asbestos cement sheets
Wavy and flat asbestos cement sheets are easily processed with various tools, so they are considered an excellent option for creating a roof.
Flat sheets are used in the arrangement of the roof of small buildings, for the arrangement of complex roofs, wavy sheets of asbestos cement are most often used. Each of the varieties has approximately the same properties, the main characteristics of the sheets are high resistance to negative environmental influences, as well as fire resistance.
If we talk about the attractiveness of external characteristics, then wave sheets look more attractive, so they can decorate the structure of any purpose. If you want to get a reliable coating for your roof at an affordable price, be sure that it will last you long enough, you should pay attention to asbestos cement sheets.