In Soviet times, asbestos-cement slate was used for roofing. Until today, this type of roofing material is considered one of the most budget-friendly and easiest to install options. Since the appearance of the product, almost no one has thought about what slate is made of, whether it is dangerous to human health, and if it is dangerous, then in what way. During the installation work, only the reliability of fastening the sheets was taken into account, so that the material did not fall from the roof during operation, and cracks and leaks did not appear. Later, many began to wonder what the product was made of, and scientists began to be interested in questions regarding the safety of materials for human health. To understand the harm caused by roofing material, you should first familiarize yourself with the production process and its components.
What shape does slate come in?
The construction products market offers to choose a material based on its functional purpose. The cross-section of the crossbar for the roof, for partitions, for a summer gazebo or fence can be:
- trapezoidal;
- wavy;
- flat.
The roofing material chosen is not only durable, but also beautiful. Almost all products have this property. For buildings with simple architectural ideas, soft slate made of mineral fiber with bitumen impregnation is suitable. Sold not only in sheets, but also in rolls.
Flat sheets of different usable areas made from asbestos cement are used for outbuildings, small fences, and temporary partitions. This is how they try to reduce the harmful effects of asbestos on humans.
Modern luxury houses are covered with slate tiles, the shape of which depends on the wishes of the customer. The slates are processed by hand, the process is labor-intensive, but the result is worth it: the building looks important and presentable.
When planning to install a gazebo on a summer cottage, they turn to plastic types of slate - modern manufacturing technology provides flat sheets of square and rectangular shapes. They bend, which allows you to make roofs and walls of complex configurations.
On a note! Surfaces with a wavy or trapezoidal profile are more durable. Withstands strong shock loads.
Country courtyard with a fence made of asbestos wave slate and a gazebo made of flat polycarbonate Source dom-i-remont.info
So the shape of the product matters. Therefore, it is important to know what the slate is made of in order to choose the one that will best perform the assigned tasks.
Number of waves
The number of waves is already determined by the name - 7-wave and 8-wave.
In individual construction, a 7-wave sheet is most often used, since it is lighter and easier to lift to the installation site manually.
At the same time, its useful area is smaller than that of an 8-wave one , since the amount of overlap for both brands is the same and the difference of one wave is not compensated for by anything.
However, a study of demand shows the predominant use of the 7-wave option.
The composition of slate and the effect on health: which one to choose
Among the points in the characteristics of slate, its environmental friendliness is not the least important. If the choice fell on beautiful corrugated slabs, then those who adhere to a healthy lifestyle will choose a material that will not harm their health. Other owners, knowing what wave slate is made of, will still buy something that suits the functionality. Let's try to figure out which slate mix with a beautiful “wave” will not harm your health:
- Plastic slate consists of 70% polyvinyl chloride (homogeneous), with the addition of fiberglass for strength. Does not emit environmentally toxic substances.
- Bituminous slate is made from synthetic and bitumen resins, cellulose fibers, and mineral fillers. Natural materials based on it make ondulin environmentally friendly.
- Fiber cement corrugated sheet is made of cement, PVA fibers, cellulose fibers, limestone. The absence of asbestos is an advantage of the material, which often influences the client’s choice.
- The metal one is made of steel coated with zinc on both sides; varnish is applied to the inner surface. Sheets are considered an environmentally friendly material.
- Rubber slate , a relatively new material on the market, is made from rubber-fabric waste, fiber optic twisted dense thread, and is non-toxic.
- Domestic composition of asbestos-cement : 85-90% Portland cement M300 - M500, 10-20% asbestos fiber with the addition of chrysolite, water.
A dangerous element is asbestos fibers, which has been discussed since the beginning of slate production. In the European Union, such coverage is prohibited. The choice of material is up to the buyer, and since asbestos fiber coating continues to be in demand, its production has not stopped. Craftsmen working with such slate adhere to safety rules during production and cutting.
This is what asbestos looks like in nature - menacing beauty Source gorod55.ru
Historical reference
Wave slate was invented in 1902
Wave slate was invented in 1902 by an engineer from Australia L. Gatchek . Its development made it possible to establish the production of roofing material on a large scale. Gradually, the product began to be produced in France, Italy and the Czech Republic. Since 1908, this material began to be made in Tsarist Russia.
slate production plant village of Fokino, Bryansk region . Since the largest mineral reserves are located on the territory of Russia, the material has gained wide popularity as a roofing solution. Before the start of World War II, there were about six large factories in the Soviet Union producing flat and corrugated slate.
Technology for making slate from asbestos concrete
It is not very important for the average consumer to know how slate is made. It’s another matter if a person plans to open a small production facility for the production of material. The demand for products is constantly growing, the aspiring entrepreneur hopes not only to invest money, but also to make a profit. Then he will definitely need knowledge about how slate is made, what slate is made from, and how the technological process itself occurs.
The formation of a slate unit begins and ends in the laboratory. Here technological calculations are made, as well as control of the characteristics of the finished product. The process itself looks like this:
- Stage 1. Loading material onto sorting belts. Depending on the type of slate, materials are loaded according to the “recipe”. Grinding of material, fluffing. Mixing components.
- Stage 2. The base for the future slate is formed in the sheet-forming machine. Primary sheet forming.
- Stage 3. Sheets with a moisture content of 25% are cut.
- Stage 4. The wavy box takes the sheet, sucks it in with a vacuum - the result is a product with a familiar wavy shape. The sheets are interlaced with metal spacers. This will give a smooth surface and hold its shape.
Slate manufacturing process Source krysha-expert.ru
- Stage 5. Marking. Plain gray slate is marked on the front side, painted - on the back.
- Stage 6. Curing chamber.
- Stage 7. Product disassembly line. The gaskets are removed and sent to cleaning and lubrication machines.
- Stage 8. “Young” slate lies in a warm warehouse for 7 days.
- Stage 9. Strength test.
- Stage 10. Dispatch if the consumer ordered gray slate.
Customers have the opportunity to purchase a color version or a lightweight sheet.
Designation and marking of sheets
Flat slate sheets have their own symbol, characterizing their type and size. It contains the letter abbreviation of the product type (LPN or LPP - unpressed and pressed sheets, respectively), dimensions (length, width, thickness - in millimeters), and the designation of the current standard.
For example, pressed sheets with a length of 3000 mm, a width of 1570 mm, and a thickness of 10 mm, manufactured according to GOST 18124-2012, are designated as LPP 3000 x 1570 x 10 GOST 18124-2012. And unpressed products with a length of 1200 mm, a width of 1120 mm, a thickness of 6 mm - like LNP 1200 x 1120 x 6 GOST 18124-2012.
The symbol of the sheets is indicated in the accompanying documents for the products, in construction drawings, etc. Directly on the sheets you can see another mark for identification - marking.
It is usually applied to slate using printing. But it is also allowed to use printed labels that are glued to sheets. A minimum of 1% of sheets in a lot must be marked.
The marking contains:
- manufacturer's name or trademark;
- batch number;
- a sign indicating the type of sheet and its thickness (a square with a number in the center - an unpressed sheet, the same square, but symbolically “compressed” by two arrows - a pressed sheet).
Table of comparative characteristics of slate materials
To help those who are still wondering which slate to buy, here is a table of comparative characteristics of various building materials:
| Slate | Natural slate | Asbestos cement | Asbestos free | Bituminous | Made of metal | Rubber | Made of plastic |
| Form | Rectangular tiles, scales, others. | Wave, flat | Wave, flat | Wave, tile, roll | Wave, flat, corrugated | Flat, roll | Wave, flat |
| Flexibility | No | Yes | Yes | Yes | Yes | Yes | Yes |
| Strength | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Toxicity | No | Yes | No | No | No | Yes | Yes |
| Fire resistance | Yes | Yes | Yes | Yes | Yes | No | Yes |
| Light resistance | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Corrosion | No | No | No | No | Yes | No | Yes |
| Weight 1 m², kg | 27 | 9-18 | 10-14 | 3-6 | 2,5-32 | 6,5 | 1,2-3,2 |
| Price 1 m², $ | $60-100 | $2-3 | $5 | $5-6 | $4-5 | $4 | $1.5-15 |
| Life time | 100-500 years | More than 30 years | More than 50 years | 15-20 years | 50 | 30-50 | 40 |
How to care for slate so it lasts longer
Despite the positive characteristics of each type, manufacturers do not hide that the material has some disadvantages:
- fragility, inconvenience of transportation, toxicity (asbestos cement);
- sunburn, fire hazard (ondulin);
- high cost (shale);
- sound conductivity, high electrical conductivity (metal);
- flammability (ondulin, rubber).
Having paid for the material and installation, everyone hopes for the declared service life of the product. But a real owner will take practical steps that will extend the life of slate sheets:
- Step 1. Initially, when purchasing, choose those that have a protective coating of water-dispersed paints and varnishes. The slate will look good for 10-12 years, but every year the color will fade.
- Step 2. Start painting. First, he will clean the slate from dust, dirt, and moss, then paint it with suitable paint. For asbestos, this is a special weather-resistant paint with an acrylic base. Rubber paint is also popular; the coating will not only be renewed, but will also become frost-resistant and wear-resistant.
Effective area
The sheets are installed with an overlap, 1 or less often 2 waves are overlapped. In this case, the useful area of the sheet is reduced by the amount of overlap.
- For a 7-wave sheet, the usable area is 1.336 square meters. m .;
- wave slate is 1.57 sq.m.
The dimensions are indicated with an overlap of 1 wave, which is most often used in construction. Sometimes in some places it may be tempting to lay the sheet end-to-end to save material.
CAREFULLY!
It is impossible to lay sheets end-to-end, as leaks will occur at all joints.
Saving one or two sheets will result in water entering the room.
Overlap width
Video description
In this video, watch the process of cleaning and painting the roof:
Caring for plastic sheets involves periodically getting rid of dust.
Metal sheets (corrugated sheets) also lose color. Paint with alkyd enamel on metal.
- Step 3. All repair, restoration, and decorative work will be entrusted to specialists with permission, the necessary tools and a wealth of knowledge, experience and skill. When receiving an application, the first thing they will do is ask what the slate is made of in order to determine the scope of work.
Briefly about the main thing
As long as humanity has lived, it has been engaged in construction. The buildings are becoming more attractive and practical every year.
The choice of roofing and facing materials, in particular slate, plays an important role in this.
Depending on the filler for the base and the material from which slate is made, there are 7 main types.
The material of the slate determines the shape: wavy, flat or trapezoidal.
Asbestos in slate poses a potential danger to workers and residents, so it is either abandoned or used with caution.
To see how the material from which slate is made affects its technical characteristics, it is worth looking at the table.
The manufacturing process is fully automated, new developments are being introduced to produce products of the highest quality. The main criterion is reliability and durability.
Caring owners can extend the life of their roof, gazebo, fence or partition. Specialists will come to your aid, they will give advice, and they will do the work efficiently and competently.
You can do small repairs yourself - repair a crack or small hole in the slate. This is a simple process that will slightly extend the life of the building.
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