Flat slate: dimensions, GOST of asbestos-cement material

This article discusses a fairly popular roofing material in construction - flat slate, and also describes the main parameters that flat slate has - dimensions, marking, weight, etc.

Asbestos-cement flat slate is a fairly cheap material, easy to install and widely used in construction.

Sheets of this material are made by molding a mixture that includes Portland cement, asbestos and water, followed by its hardening. Asbestos fibers evenly distributed in the cement mortar form a reinforcing mesh, which significantly increases the tensile strength of the material and its impact strength.

The mechanical characteristics of asbestos depend on a number of factors:

Asbestos content;
Asbestos quality (average fiber length and diameter);
Uniform distribution of asbestos fibers in cement;
Chemical and mineralogical composition;
Density of asbestos-cement stone;
Fineness of grinding, etc.

The quality and dimensions of flat slate, as well as any material, depend on the technologies and equipment used in production, in particular, on how modern production lines are installed at the plant.

Modern asbestos-cement flat slate is painted during production, which increases both its decorative properties and service life.

For this, silicate paints or paints with a phosphate binder are used, and various pigments are also used. Previously, flat slate had either a gray, featureless tint, or was painted green or red.

Today, this material is produced in a variety of colors:

Red-brown;
Chocolate;
brick red;
Yellow (ochre);
Blue, etc.

The paint used to paint flat asbestos-cement slate creates a protective layer that prevents the destruction of the product, increases its resistance to frost and reduces moisture absorption.

In addition, this protective coating slate roof significantly reduces the amount of asbestos released into the surrounding air and prolongs the life of the material by about one and a half times.

Sheets of asbestos-cement slate are usually used to cover roofs, the slope of which exceeds 12 °. The weight of 1 square meter of such a roof will be from 10 to 14 kg.

Flat slate, the dimensions of which can be different depending on the situation, can be used to cover both residential and commercial buildings and structures.

Flat slate is most often used in the following areas of construction:

External and internal cladding of residential, industrial, public and utility buildings and structures;
Coating roofs;
Installation of wall coverings according to the “Sandwich” principle;
Production of so-called "dry screeds";
Manufacturing and installation of various structures with a wide profile;
Fencing of loggias, balconies, etc.;
Also, this material (depending on the size of the flat slate) is used for various horticultural and agricultural purposes.

The main advantages of flat slate are:

Quite low cost;
Profitability in the construction and processing of building structures;
Ease of installation, which is also provided by various sizes of flat slate;
Increased fire safety;
Resistance to low temperatures in winter;
Reduced thermal conductivity;
Increased resistance to various negative external influences.

Parameters and characteristics of flat slate

According to GOST, flat slate is marked with alphabetic and numeric characters, which are deciphered as follows:

LP-P stands for flat pressed sheet;
LP-NP stands for unpressed flat sheet;
The numbers indicated in the marking reflect the size of the flat slate - its length, width and thickness;
GOST must also be indicated at the end of the marking.

Example: marking "LP-NP-3.5x1.5x7 GOST 18124-95" means that this material is sheets of flat unpressed asbestos-cement slate, the length of which is 3500 mm, the width is 1500 mm, and the thickness is 7 millimeters. The material is made according to the specified GOST.

Next, consider the main shapes and sizes of flat asbestos-cement slate sheets produced in modern Russian industry.

Standard flat slate sheets are made in the shape of a rectangle and have the following dimensions:

Length - 3600 mm; width - 1500 mm, thickness - 8 or 10 mm;
Length - 3000 mm; width - 1500 mm, thickness - 8 or 10 mm;
Length - 2500 mm; width - 1200 mm, thickness - 6.8 or 10 mm.

GOST 18124-95 regulates the following requirements for sheets of flat asbestos-cement slate:

Rectangular shape of sheets;
The deviation in squareness should not exceed 5 mm;
The deviation from the plane for a pressed sheet is no more than 4 mm, for an unpressed sheet - no more than 8 mm;
Dimensional deviations should not exceed 5 mm.

The main differences between pressed flat slate and non-pressed slate are as follows:

Bending strength (23 MPa for pressed slate and 18 MPa for non-pressed);
Material density (1.80 g/cm³ – pressed, 1.60 g/cm³ - unpressed);
Impact strength (2.5 kJ/m² – pressed, 2.0 kJ/m² - unpressed);
Resistance to low temperatures (50 alternate freeze / thaw cycles for pressed flat slate, 25 cycles for non-pressed);
Residual strength, which is 40% for pressed sheets, 90% for unpressed sheets.

The marking of a batch of sheets of flat asbestos-cement slate according to GOST 18124-95 is carried out as follows: each batch (at least 1% of the batch) must have a glued label indicating:

Name of the manufacturer;
Batch number;
date of manufacture;
Symbolic designation of the sheet type (pressed or non-pressed);
The thickness of the sheets and their dimensions.

Transportation and storage of sheets of flat asbestos-cement slate is carried out in packaged form, using pallets or wooden spacers.

The maximum weight of one package, regulated by GOST 18124-95, is 5 tons. Stacks of flat slate sheets should be stored on pallets or spacers. The total height of packages stacked on top of each other should be no more than 3.5 meters.

When choosing for slate roofing you should carefully read its marking, this will allow you to be sure that you are purchasing high-quality material suitable for the needs of a particular construction.

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