In our climate zone, we have to use every opportunity to insulate the house. This applies to walls, floors, windows, doors and roof. Floors were insulated even before the appearance of modern synthetic building materials. Often we used improvised materials, of which there were many in our region. A special attitude has always been to the remnants of wood after processing – sawdust. The article deals with floor screed from sawdust, which has not ceased to be relevant today.
History of the issue
Before the advent of modern technology, sawdust was used as a floor insulator. To do this, they were usually mixed with clay and other materials. In this form, wood waste was used for more than a century.
In the Soviet Union in the sixties of last century, engineers developed a new building material for construction based on waste wood and cement – arbolit, also sometimes called sawdust-concrete or wood-concrete At the same time it was standardized and began to mass produce ready-made blocks. There were about 100 plants in the country specializing in arbolite. The great advantage of the material was its considerable cheapness, because the country had a large woodworking industry and large mountains of waste in the form of shavings and sawdust.
Preparation of raw materials
For the screed are taken ordinary sawdust, which can be found in large quantities at sawmills. Before using them pre-treated with antiseptic agents and dried. Then they are interspersed with burnt lime. This is necessary to do to protect against rodents that live in our homes. The fact is that untreated wood particles are a great place for them to live and breed. Hydrate lime needs at least a tenth of the mass. After backfilling, the materials are mixed well with a shovel to create a homogeneous mass.
Advantages of screed with sawdust
- Eco-friendliness and safety for people. According to all modern standards screed based on cement and sawdust is recognized as environmentally safe material. This is especially relevant after the appearance of many synthetic building materials. The composition of the mixture contains only natural components. Due to the high content of wood, such a floor creates a good microclimate indoors and does not pollute the territory around the house;
- Low thermal conductivity. The indicators on this parameter are at the level of the most modern materials. The coefficient of thermal conductivity is about 0.32 W/m3 with a density of 800 kg/m3. The wood-cement floor is almost on par with the popular gas foam concrete;
- High strength. Numerous tests in the lab have shown the high strength of wood-cement concrete. It is much higher than most competitors. Such properties are obtained due to the reinforcing qualities of wood particles. They bind the cement and create a strong material;
- Non-combustibility. Despite the content of a large amount of wood element sawdust concrete is completely non-combustible. This is due to the enveloping of individual particles with a cement-sand mixture. In a fire, individual foci cannot transmit the fire, and it gradually subsides. Sawdust concrete can withstand high temperatures of about 1200 degrees Celsius for several hours;
- Resistance to moisture. Sawdust concrete is highly resistant to moisture. Depending on the resulting density of the building material can absorb up to 12% of water. If you use a special additive, the water-repellent properties reduce this figure in half.
Disadvantages of screed with sawdust concrete
In addition to the large number of positive aspects of the material has a small disadvantage – sawdust-concrete screed will dry out almost a month after the filling. [ads-pc-1]
The process of making a warm floor is not much different from the usual cement screed. The main difference is to conduct work in several stages. The peculiarity of the second layer is to use less wood raw materials. First, the first layer is poured. Approximate composition: 2 parts by volume of sand, 1 part of cement and 6 parts of sawdust. After drying, the second layer is poured. Take only 3 parts of wood waste for the same amount of cement and sand.
Useful tips for creating a warm floor based on sawdust concrete
- Do not forget to add 5-10% dry lime to the wood waste to prevent the subsequent development of bacteria, benders and rodents;
- Fresh wood waste contains substances that prevent good adhesion of the surface to the cement, so you need to use at least 2 months after sawing the wood.
- If this is not possible, the addition of liquid glass helps;
- For additional protection against rodents, you can add boric acid or copper sulfate to the concrete;
- It is better to pour the floor in the summer. At high temperatures, it is easier to dry the wood waste, which is favorable for the further service of the floor;
- The amount of water poured into the solution depends on the size of the particles. It is best to buy for construction works medium fractions. Small ones create too much dust during the work, and large ones have worse insulating properties. It is better to take the waste from the pre-dried in the chambers boards;
Do not discount such a cheap and convenient building material as sawdust-concrete. In our conditions, it does an excellent job and makes the house warm and safe.