Advantages and disadvantages of sawdust as a heat-insulating material, recommendations on the choice of components for creating an insulating layer on ceilings, compositions based on sawn timber waste, the method of laying mortar on the floor. Insulation of the ceiling with sawdust is the use of small waste wood to retain heat in the room, which, after appropriate processing, form a coating with good thermal insulation characteristics. Lightweight, alone or in combination with other means, has been used for centuries to insulate floors, but today it is used less and less. We will talk about insulating coatings based on this substance in this article.
Features of thermal insulation of the ceiling with sawdust
Sawdust is small wood chips or dust that is generated when lumber is processed. Thermal insulation of the ceiling with this bulk mass has no competition in terms of "price-efficiency" criterion, but in other characteristics it is significantly inferior to modern heat insulators.
To increase its effectiveness, it is mixed with clay, lime or other substances, and then applied to the ceiling from above, from the side of the attic or second floor, or from below from the room.
This is a versatile material that is suitable for residential buildings and outbuildings. It is not recommended to use sawdust in its pure form, they will quickly deteriorate. To extend their service life, they are impregnated with various means - antiseptics, fire retardants, etc.
Lumber waste is flammable, therefore, before insulating the ceiling with sawdust, places near flammable objects are isolated. The electrical wiring is pulled into a metal tube, the chimney is lined with non-combustible materials.
The main way to insulate the ceiling is from the outside, from the attic side. The thickness of the layer can be up to 30 cm. On top of it, flooring can be made for movement. It is allowed to cover the sawdust with a cement-sand screed, having previously covered them with a net. The solution to the overlap can also be applied from the inside, but the effect will be insignificant due to the small layer.
Insulation of the ceiling in the house with sawdust is very laborious compared to modern insulators, but the result will pleasantly surprise the owners.
Advantages and disadvantages of ceiling insulation with sawdust
It is not very convenient to work with small fragments, but there are many supporters of this method of insulation. The owners appreciate the material for the following qualities:
- This is an environmentally friendly material that does not emit harmful substances and does not provoke an allergic reaction in humans. To prepare the solution, only natural ingredients are used - sawdust, sand, clay, lime, and the owner himself will not add toxic agents.
- The price of the material is minimal, often you can get it for free, subject to self-pickup. The work does not require special skills and special styling tools.
- The service life of the insulation depends on the quality of the installation, but it is still considered large.
- The thermal conductivity of the sawdust is very low. Good insulating qualities are transferred from the solid wood.
The substance has serious drawbacks, because of which many people prefer to buy modern thermal insulation products. Negative properties include:
- Flammability under the influence of high temperature, which creates a high risk of fire in the attic;
- Damage by microorganisms, insects and rodents;
- Hygroscopicity;
- Traceability.
Ceiling insulation technology with sawdust
To use sawdust as ceiling insulation, it is necessary to properly form a protective layer. The simplest option is to create an insulating sawdust coating on the attic floor. The effect will increase if you use a mixture of a substance with other materials. To obtain a good result, two conditions are necessary: choose the right consumables and follow the technology of work.
Material selection
To reliably close the ceiling, purchase only high-quality sawdust. When choosing, consider the following recommendations:
- For thermal insulation with clean material, you will need dry products that were received at least a year ago. It is impossible to use elements of fresh wood, they must lie for some time for "ripening". Otherwise, cement will not stick to them due to the presence of specific substances in their composition. When using a solution, the moisture content of the substance does not matter.
- There is good insulation in carpentry workshops, where only dry products are used. They do not rot and do not contain bugs. the wood is dried at a high temperature.
- Please note that the sawdust from the round timber is wet. They must be dried in the summer with occasional stirring. This material has a low percentage of sugar, which reduces the risk of decay. During drying, the material must not be covered with plastic wrap, otherwise it will resist. After drying, it is cleaned of large fragments and debris using a construction sieve.
- Do not buy a substance obtained from bark processing. Insects can remain in it, which will ruin the ceiling.
- Give preference to medium-sized fractions obtained from sawing wood. They have better thermal insulation characteristics compared to large fragments. However, remember that waste that is too small weighs more, and in the process of use, they become dusty. Fragments of medium size do not have such disadvantages, moreover, less cement is needed to prepare the working solution. For the same reason, discard shavings.
- Insulate the ceilings of residential buildings with sawdust of coniferous trees. They contain a resin that keeps mold and mildew out. Waste from pine lumber is the lightest, from deciduous and fruit - heavy and dense.
- In baths and saunas, fragments of deciduous trees are used, they are more resistant to dampness. To enhance the effect, they are mixed with ash.
- The clay for preparing the solution should be greasy, soapy and slippery to the touch, like a piece of bacon. The fatter the component, the more plastic the mixture is.
Surface preparation before insulation with sawdust
The overlap must be prepared for insulation. The refinement consists in creating a reliable base that can withstand a large weight (if it is a solution) or will not miss small fragments (if clean sawdust is used). Perform the following operations:
- Clean dirt from the attic. Remove sharp elements from the surface that could damage the waterproofing membrane.
- If the event is being held at the construction stage, hem the floor beams with boards 25-30 mm thick. The size depends on the pitch of the bar. It is recommended to use shunted flooring materials made from dry planed boards, but such products are expensive. They are laid flat and nailed with nails 100 mm long or screws 50-60 mm long, 2 pcs. at each attachment point. Drive nails at an angle to increase reliability, because sawdust-based mixtures are heavy.
- Treat lumber with special compounds against fungus, bugs and to increase fire safety.
- Fill the slots with polyurethane foam.
- Put waterproofing on the floor - plastic wrap, roofing felt or rubimast.
- Lay the sheets with an overlap of 15-20 cm on vertical walls and on adjacent pieces.
- Cover the joints of the cuts with bitumen. Attach the film to the partitions with a stapler.
Ceiling insulation with sawdust and cement
This option is usually used if the floor slab is concrete. For work you will need: 10 buckets of sawdust, 1, 5 buckets of water, 1 bucket of cement.
The process of preparing the mixture is as follows:
- Mix sawdust with cement in a clean container. To facilitate the process, you can use a concrete mixer.
- Add some water and mix again. You should get a wet solution with chips coated with cement. The readiness of the mixture can be determined after squeezing the substance with your hands. If water appears and it does not run, you can start laying. If water drips and the insulation crumbles, add lumber or leave the insulator in the container without a lid for a day. Excess moisture will disappear.
- To prevent sawdust from rotting, add copper sulfate. Add 3 tbsp. tablespoons of the product in a bucket of water, then slowly pour the contents into the insulation while constantly stirring the mixture, controlling its consistency. Copper sulfate is poisonous, so work with gloves. This substance is not recommended for use in saunas and baths, because when heated, it emits fumes that are harmful to humans.
- Place the substance on the floor of the attic, compacting slightly. After drying, you will get a dense cover (lightweight concrete) with good thermal insulation properties, on which you can walk.
- Lime can be used instead of cement, but it does not create a sufficiently strong coating.
- To move around the attic, you will have to use wooden flooring. But thanks to lime, mice and insects do not live in the bulk mass.
Insulation of the ceiling with sawdust and clay
This method is ideal for private house ceilings. In addition to thermal insulation, the coating plays the role of a hydro-barrier: when the roof leaks, moisture is absorbed by the clay and does not enter the room. For work, you will need large and small fragments. First, a solution of large sawdust is placed on the base with a layer of 5-10 cm. Above is a second ball with small fragments. The order of operations is as follows:
- Pour the clay with water in a 5: 2 ratio and leave to get wet. Stir the ingredients until a lump-free, viscous consistency is obtained.
- Sprinkle large sawdust with lime in a ratio of 10: 1, add the mass to the clay solution and mix thoroughly. You can check its readiness with a stick. After sticking into the insulation, it should remain vertical.
- Spread the mixture with large fragments evenly on the floor of the attic. When laying, it must be lightly compacted. For this purpose, make a light rammer with a 25x25 cm work area.
- It is necessary to lift the mixture into the attic in small portions, usually with a bucket. If the roof is not installed, use a winch.
- Such a coating dries for about a month, so it is advisable to perform work in the summer.
- After 4 weeks, prepare a solution with small fragments. It is placed on the finished floor, flush with the floor beams, and waited until it dries. If small cracks appear, seal them with the same compound. The insulating layer will be very durable and can be walked on even without decking.
Insulation of the ceiling with sawdust with lime and alabaster
For this method, you will need components in the following proportions: sawdust - 85%, lime - 10%, alabaster - 5%, water - in volume for diluting stucco.
To prepare the solution, all components must be mixed. Cook the mixture in small portions so that it does not freeze in the cooking container. For large areas, more than 20 servings are needed. The coating is not dusty, does not burn, and mice do not settle in it.
Cover the floor with substance, compact and level with a board. The total layer of the insulator should be no more than 10 cm. After drying (after 3-4 weeks), you can mount a subfloor for ease of movement.
Ceiling insulation with clean sawdust
The loose mass can be poured into the attic in its pure form, if it has been pretreated with an antiseptic to protect it from decay. Experienced summer residents mix it with broken glass or tobacco leaves to scare off mice.
The order of work is as follows:
- Place a vapor barrier film on the subfloor of the attic. Without it, the coating will get wet and quickly rot.
- Pour sawdust on the ceiling up to the upper level of the beams, usually 15-20 cm, level, but do not tamp.
- After two weeks, cover them with a vapor-permeable superdiffusion membrane, which will prevent the fragments from getting wet from above and will not prevent moisture from evaporating from them. If it is absent, use the old method - pour a layer of ash from the oven.
- To move around the attic, attach the flooring to the attic beams. Nail the lumber with clearances for ventilation.
How to insulate the ceiling with sawdust - watch the video:
The effect of using sawdust for ceiling insulation can be compared with the use of modern products. All operations are performed independently, it is only important to properly prepare the solution and follow the laying technology, without missing any of the steps.
