Pros and cons of warming an attic with sawdust, rules for choosing raw materials, technology for creating an insulating layer, preparing a bulk mass for laying. Insulation of the attic with sawdust is the creation of an insulating layer on the floor of wood dust. For its formation, a thick ball of pure raw materials or mixtures based on it is applied to the floor of the technical floor. The characteristics of the material are not inferior in quality to modern synthetic products, but to obtain a high-quality result, the bulk mass must have special properties. For information on how to fix roof heat leaks with sawdust, see this article.
Features of the use of sawdust for warming the attic
Dust is a waste of lumber that remains after cutting. The main source of raw materials is the sawmill, high quality bulk material can also be found in furniture carpentry workshops.
Currently, sawdust is rarely used for attic insulation. They are mainly used in the construction of houses in rural areas, summer cottages, various outbuildings. Only the floor of the attic is covered with dust, thus preventing the leakage of almost 40% of the heat from the living space, while the upper floor remains cold. The roof is not covered with this bulk mass; this requires other materials.
The easiest way to insulate a floor is to completely fill it with dry dust. It is often mixed with other substances, which makes it possible to radically change the quality of the coating and improve the performance properties.
It is recommended to treat the bulk mass with antiseptics and fire retardants. Special means reduce the degree of flammability of the material, but electrical appliances, cables, chimneys and other hot structures should be carefully insulated.
Advantages and disadvantages of attic insulation with sawdust
Waste wood until recently was considered the main option for eliminating heat leakage through the roof. Now they are increasingly being replaced by modern thermal insulators, but this material is still popular in the private sector.
Masters appreciate it for such advantages:
- Low cost. Sawdust can often be obtained free of charge, spending money only on delivery. In most cases, this is the main reason why the owners buy dust for insulating the attic.
- A properly prepared substance has a long service life.
- The work can be done by one person, even without proper experience.
- The free-flowing mass has a very low thermal conductivity. Such properties are transferred from wood.
- No special equipment is needed to insulate the floor.
- Sawdust belongs to environmentally friendly materials. They contain no components harmful to humans.
The insulation has a number of disadvantages for the purpose, which the consumer should be aware of:
- The substance burns well and cannot be used in fire-hazardous premises.
- Mice settle in the bulk. It is quickly attacked by fungus and mold.
- The raw material is very loose and shrinks.
- The dust absorbs moisture well, therefore it is covered from all sides with a waterproofing film.
Attic insulation technology with sawdust
To minimize heat leakage through the roof, the insulating layer should only be formed from quality raw materials. In addition, it is important to follow in strict order the instructions for thermal insulation of the ceiling with sawdust. Let's talk about this in more detail.
The choice of materials for insulation of the attic
You can check the condition of the bulk mass without using special tools, applying our recommendations:
- When insulating a cold attic with sawdust without binders or a mixture of dust and dry lime, control its moisture - the material must be absolutely dry. Such raw materials can be found in carpentry workshops that only work with dry wood. It is processed in special installations at high temperatures. After drying, there are no bugs in the insulator.
- If the substance is mixed with clay, cement, alabaster, etc., the moisture content of the components does not matter. But even in this case, give up the dust from the bark, which is full of insects. They can climb onto the wooden structures of the attic and damage them.
- To prepare a mortar with the addition of cement, sawdust must be produced at least a year ago. This is due to the fact that they contain special substances that prevent the cement from sticking to the fragments.
- Choose raw materials with medium chunks. Small ones increase the weight of the coating and create dust, while large ones are poorly impregnated with protective agents. Also, do not use shavings.
- Pine and spruce sawdust is the lightest. They contain a large percentage of resin, which protects from decay. Fruit tree dust is heavier. Waste from oak and larch does not absorb moisture well, so they are often used to insulate bathhouse attics.
- For the preparation of sawdust-based solutions, you can use oily clay. It is flexible and fills voids well. The quality of the material can be determined by wetting and kneading it in your hand. The clay should be slippery to the touch and should go through your fingers with the tape.
- Only natural wood waste is suitable for thermal insulation. Residues of chipboard, MDF, OSB and other glued panels are not suitable due to the presence of synthetic binders. After cutting them, very fine particles, almost dust, are formed.
Preparatory work
Sawdust is a very vulnerable product, it quickly deteriorates, therefore it is not used in its natural state. Before laying, the raw material must undergo special processing. Add fluids to waste to prevent rot, mildew, rodent-repelling and fire hazards. The procedure is performed as follows:
- Place plastic wrap under the canopy and scatter lumber waste.
- Toss the dust with an antiseptic and fire retardant. Antiseptics include such common agents as copper sulfate and boric acid. It is not recommended to insulate the bath with sawdust with copper sulfate. At high temperatures, it begins to release toxic fumes.
- Wait for the bulk to dry. To make the process end faster, carry out the operation in the summer. Stir occasionally while drying the sawdust. Do not cover waste with plastic wrap.
- Make sure that the raw materials are not exposed to sunlight. A small percentage of sugar is retained in well-dried fragments, which provides additional protection against decay.
- The moisture content of the material can be determined independently. After squeezing in a fist, the sawdust crunches, no water is released.
- The loose mass should be free of mold and mildew.
- Remove large fragments before filling the attic.
- It is not necessary to dry the sawdust for liquid solutions.
Before work, it is necessary to prepare the floor for laying the insulator. Operations depend on the condition of the attic floor.
These include the following procedures:
- If the work is carried out at the stage of the formation of the floor, hem the load-bearing floor beams from below with boards 25-30 mm thick. The size depends on the distance between the logs: the larger the step, the more massive the lumber. The best option is to use tongue-and-groove boards, but they are not cheap. For fixing, you need nails with a length of 100 mm or screws of 50-60 mm. Each attachment point should have two hardware. To increase reliability, drive nails at an angle to the plane.
- Pass the electrical wires through a metal tube.
- In an exploited attic, remove all things from the ceiling, clean it of dirt. Make sure there are no sharp elements that could damage the waterproofing membrane. If there is a clean floor, dismantle it to expose the subfloor.
- Seal large cracks with foam.
- Lay waterproofing - plastic wrap, roofing felt or rubimast. Place the pieces with an overlap of 15-20 cm on the walls and on adjacent cuts. Connect the joints with reinforced tape. The material is necessary in the case of using a liquid solution so that water does not leak to the lower floor.
Insulation of the attic with sawdust and clay
Unlike the previous version, such a mixture will be cheaper due to the lack of cement. For work, sawdust, clay and water are needed in a ratio of 10: 5: 2. You can mix the solution in a concrete mixer. The coating is applied in two layers. Large particles are placed below, small particles are placed on top. The order of performing operations:
- Pour water over the clay to get wet.
- After a day, mix the components until a homogeneous composition without lumps.
- Pour the liquefied soil into a concrete mixer, add coarse sawdust and turn on the machine.
- After a while, check the quality of the solution. To do this, fill a bucket with the mixture and stick in a stick. She shouldn't bend over.
- Cover the attic floor with a layer of 20-30 cm. Smooth and compact the covering. For this purpose, you can make a manual rammer.
- After complete drying, prepare fine sawdust in a similar way and repeat the procedure. The dried coating should be free of cracks. If defects are found, repair them. Clay dries for a long time, at least a month, so it is recommended to do the work in the warm season.
- The finished floor is very durable and can be walked on without decking.
Insulation of the attic with sawdust and cement
Thus, the concrete floor of the attic is thermally insulated. Before work, prepare sawdust, water and cement in a ratio of 10: 1, 5: 1. Use a concrete mixer to stir. Do not add too much cement: the more, the less heat is retained. Perform the following operations:
- Pour cement, dust into a concrete mixer and move them carefully.
- Add water and turn on the mixer again.
- After obtaining a homogeneous mixture, check its quality. To do this, squeeze some solution in the palm of your hand. If water flows out and the lump falls apart quickly, add lumber. Excess moisture will evaporate on its own if the container is left open.
- Pour the insulation onto the floor and distribute it evenly over the surface, lightly compacting. The thickness of the layer should be 25-30 cm. After 2 weeks, when it is dry, check the quality of the coating. The heat insulator must be able to support the weight of the person. A squeaking sound may be heard when walking.
- Lime can be added instead of cement, but the flooring will not be strong enough. You will need wooden shields to move around the attic.
Warming with sawdust with lime and gypsum
The attic can be insulated with a mixture of sawdust, lime-fluff, gypsum in a ratio of 85: 10: 5. Water is poured into the solution in the amount required for stirring. Gypsum retains the porous structure of the substance, which increases the heat-insulating properties of the material. Lime artificially shrinks the mass, extending its service life. The mixture is used for insulating small rooms.
This option differs from other mixtures in a short curing time, as well as in the absence of shrinkage after application to the floor. First, combine the mass with lime, and then add gypsum. Prepare the solution in small portions so that it does not freeze in the container. It does not burn, does not produce dust, and mice do not live in it. Pour the mixture with a thickness of 20-30 cm, and then tamp.
Warming with dry sawdust
To create an insulating layer, you will need dry sawdust mixed with broken glass, tobacco leaves, lime and other substances that can scare off mice.
Next, do the following:
- Lay a waterproofing film on the floor of the attic to protect against damp air coming from the bottom of the living area.
- Fill the ceiling with waste flush with the upper surface of the logs (25-30 cm).
- Smooth the cover, but do not tamp. Leave it to shrink for 2 weeks. All this time, the room must be ventilated. Cover the ceiling with a vapor-permeable superdiffusion membrane that will protect the insulation from leaks through the roof and will not interfere with the evaporation of moisture from the raw materials. Seal the film joints. Instead of a membrane, sawdust can be covered with a layer of ash from the oven.
- If the attic is planned to be operated, install the decking. Leave spaces for ventilation between the boards.
How to insulate an attic with sawdust - watch the video:
[media = https://www.youtube.com/watch? v = 9MkFisA6YkU] The effect of using dust for thermal insulation of a technical floor is very significant and differs little from the use of synthetic products. All procedures are done by hand. Before insulating the attic with sawdust, study the technology for performing work and do not ignore the proposed operations.
