How to insulate a house with clay and straw with sawdust with your own hands: Review

Before the advent of modern building materials, people actively used natural materials that had the ability to retain heat to insulate houses. For many centuries, clay with sawdust was used to insulate houses made of stone and wood.

Scheme of floor insulation with sawdust.

Clay with sawdust has unique thermal insulation properties and is not only a means of insulation, but also waterproofing. The waterproofing and insulating properties of clay, supplemented with sawdust, can even be used for arranging baths, since this material is not subject to destruction even under possible contact with hot steam, which not all building materials used for insulation and waterproofing can effectively cope with. .

Thermal insulation of the ceiling with sawdust

Insulating the ceiling space of a bathhouse using sawdust is quite common. This material is good for use in baths that will be used by children and the elderly, since it is completely safe for human health.

But do not forget that if you use only sawdust, it can become a source of the following problems:

• high level of fire hazard, any spark is potentially dangerous;
• too much dirt, a draft can cause a mess.

Insulation of a bathhouse ceiling with clay and sawdust

Do not forget that the ceiling “pie” must be executed according to all the rules:

• First you need to prepare the ceiling - arrange the flooring or assemble the formwork frame.
• Divide the ceiling into fragments to make work easier.
• Be sure to take care of the insulation from moisture - lay down roll insulation material or, at worst, cover the existing cracks with a clay solution.
• Lay down the wood-clay mixture.
• If necessary, when the clay is completely dry, you can build a sand layer on top of it.

Clay is diluted with water in the proportion of 4 or 5 buckets per metal barrel of water. Then the mixture is left for several days to detune, after which it must be thoroughly stirred, draining off excess water. Once the solution is homogeneous, sawdust is introduced into it. The ratio of sawdust to clay is 2/3 to 1.

The ceiling space is laid with the finished solution. For central Russia, the recommended layer thickness is from 8 to 15 centimeters; for regions with a harsh climate, the backfill thickness can be increased to 30 centimeters. It is not necessary to exceed this figure, since the weight of the clay is significant and can create an excessive load on the building structure. The composition is applied evenly in two passes. First, the base layer is laid. As it dries, it is re-installed.

Insulation of a bathhouse ceiling with sawdust and cement

The arrangement of layers is similar to the previous method, with the difference that waterproofing is not limited to covering the cracks. Film materials for waterproofing are indispensable in this case. Such a solution will have even more significant weight and put a greater load on the house. The maximum thickness should not exceed 15 centimeters. The minimum layer is 8 centimeters. Mixing the cement mixture is faster, especially when using a concrete mixer. The mixture is mixed based on the following proportions: 1 part cement, 2 parts sand and 6 parts sawdust. The insulated surface will require additional leveling.

Advantages and disadvantages

In modern crisis conditions, sawdust can be an excellent alternative to expensive types of thermal insulation materials, which are presented in large quantities on the market. Insulating a new or old house, bathhouse or other outbuildings with sawdust provides a significant reduction in costs.

Despite the fact that the thermal conductivity of this material is significantly inferior to insulation materials such as mineral wool or polystyrene foam, sawdust has a large number of advantages, which include:

• maintaining an optimal level of humidity indoors throughout the year due to the fact that such material removes excess moisture accumulated in the house;
• excellent vapor permeability, which other industrially manufactured thermal insulation materials do not have;
• resistance to high humidity and condensation that appears on various surfaces due to temperature changes;
• the ability to absorb and release steam back when the air in the room is too dry.

This is a natural, environmentally friendly material that helps create a healthy environment in the home by retaining heat and regulating the level of humidity in the room. Sawdust, unlike other thermal insulation materials, does not block the process of vaporization and does not allow the creation of high humidity in the house.

This is an environmentally friendly material that creates a healthy microclimate in the house. Sawdust not only does not emit toxic substances, but creates a comfortable microclimate thanks to the phytoncides that are found in wood of various species. This natural insulation is great for allergy sufferers.

The advantage of sawdust is its low cost compared to industrial insulation. If desired, they can be removed from the sawmill or woodworking shop for free, paying only for transportation costs.

This is reliable thermal insulation that can last a long period of time if you treat the sawdust with an antiseptic before use, which will protect it from pests, rot, mold and mildew.

This is a universal insulation material that can be used to insulate an entire building. When working with sawdust, you do not need to use special tools. The material can be backfilled in any hard-to-reach places, thus providing good thermal insulation along the entire circuit.

Despite having a large number of advantages, sawdust also has a number of disadvantages:

• high degree of flammability;
• the ability to attract rodents that live in bulk dry materials;
• tendency to caking, which can result in the formation of voids in places of thermal insulation.

These disadvantages can easily turn into advantages if you treat wood shavings with fire-retardant compounds before use. To prevent sawdust from caking, they are mixed with compounds that maintain their original volume. Boric acid and slaked lime are used against rodents.

What is the reason for the popularity of the method?

Close attention has always been paid to home insulation. The modern market offers a wide range of thermal insulation materials. All insulation materials have their pros and cons. Despite this, insulating the ceiling with sawdust in private homes still remains relevant. What is this connected with? Why do we still insulate houses using this material?

Firstly, the method is quite effective, as proven by many years of using sawdust. And numerous positive reviews confirm this. Secondly, the material retains its properties for a long time. Thirdly, insulating the ceiling with sawdust will be very cheap. Compared to all modern insulation materials, wood shavings are several times cheaper.

This factor is especially preferable for consumers. Moreover, some construction companies give away the material completely free of charge or offer it at a purely symbolic price. And fourthly, this method is easy to install. Even a person without experience will be able to cope with the work with his own hands.

Insulating walls with sawdust: pros and cons

To insulate walls with sawdust, wood waste from hard wood, namely ash, spruce, pine, etc., is most often used.

For this purpose, oak sawdust is considered the most suitable option. These raw materials are expensive, but they help preserve heat in the house even in 30 degree frost.

The best option is pine shavings - it contains resin that repels rodents and bugs.

It is best to take sawdust of the medium fraction, since small ones will produce a lot of dust, and large ones will have little effect.

NOTE!

The sawdust should not contain any third-party aromas or elements. Wood processing waste must be chamber dried. It is advisable to dry shavings that have natural moisture in the fresh air. Without pre-treating the material with an antiseptic, it cannot be used.

After the sawdust is completely dry, it is worth adding a mixture of copper sulfate and slaked lime (10% by weight).

Insulating external walls with sawdust has its advantages:

• it is easy to work with;
• getting sawdust will not be difficult for you. There are wood processing enterprises in many localities;
• long service life;
• high efficiency;
• environmental Safety;
• low specific gravity;
• excellent noise-absorbing and heat-insulating properties;
• This product can be purchased at the sawmill for free or for a nominal fee.

Thermal insulation device

Disadvantages of the material:

• the insulating layer is of considerable thickness. If the sawdust layer is small, then their effectiveness as insulation will be minimized;
• high fire hazard of the material. Wood shavings readily burn. Using sawdust as insulation for walls greatly increases the likelihood of a fire occurring and spreading;
• The material is not resistant to moisture, it absorbs it well. As soon as liquid gets on the insulating layer, it is fraught with negative consequences: dampness, mold will appear, and harmful insects will appear.

Therefore, if you decide to install such a structure, you need to pay special attention to vapor and waterproofing. If these layers are made without following the technology, the insulation will quickly become unusable

To prevent sawdust from being exposed to moisture, they are treated with special reagents.

But the cost of such material becomes many times higher, and it also becomes toxic and can even cause an allergic reaction. It is not safe to use processed sawdust as a thermal insulation material in a residential frame house.

Insulation of walls with sawdust and lime

In order to make wall insulation, which includes lime and sawdust, you need to take these ingredients in a ratio of 1:10. You need to add a little antiseptic solution (25g per 1 bucket) to the prepared mixture.

Then the mixture must be poured into the walls and compacted. Sawdust treated in this way does not sag and bugs do not grow in them.

Sawdust with lime

Sawdust with straw

Straw is an excellent material for wall insulation. For these purposes, you can use straw from barley, oats, rye, and wheat. It is first pressed and then tied with wire, cord or mesh. Straw insulation has a density of 90 – 125 kg/m3; as a rule, straw “slabs” are plastered on top.

The advantage of straw is that it breathes. The downside is that it ignites quickly and burns well. To prevent this from happening, it is treated with fire retardants.

Sawdust with straw

How to make sawdust with clay

If you use sawdust as a base, you can prepare a solution for plaster. To do this, you should mix sawdust with water, cement, clay and newspapers.

A composition obtained from clay and sawdust is used to plaster the walls inside the building. Slabs are sometimes made from such a solution, compacted and dried well. The resulting sheets are used as thermal insulation material.

Sawdust with clay

Types of sawdust

Sawdust is particles of processed wood that are formed during the sawing process. In appearance they resemble dust. There are also wood wastes such as shavings. They are formed as a result of drilling or planing. The chips are large in size, which is the main difference. The length can vary from 30 to 50 mm.

Sawdust is divided into different fractions, which differ in size. The length depends on the characteristics of the technological process and the equipment used. The size can vary from 5 to 30 mm.

To insulate the ceiling of a house, it is better to choose the middle fraction. Large chips have less thermal insulation properties, and material that is too small is more difficult to work with. When insulating, elements scatter, generate dust, and become clogged in the respiratory tract.

Sawdust produced in chamber-drying carpentry production has good properties. This material does not need to be dried additionally, which increases the service life of the insulation. If waste was generated as a result of processing wood with natural moisture, then it will have to be dried before use. Sawdust is placed under the canopy. It is forbidden to cover them with polyethylene, as they will rot and begin to rot.

It is recommended to choose shavings from deciduous wood for the ceiling in the bathhouse, and from coniferous wood for the house. They contain resin, which increases resistance to external influences. In addition, this material is less susceptible to damage by bugs and insects.

To insulate the ceiling, you should take shavings that have lain for 6-12 months. During this time, sugar comes out of the particles, which contributes to the development of rot. If you keep sawdust for more than a year, they can also begin to rot.

For thermal insulation, you should take clean sawdust, free of debris and foreign inclusions. If necessary, the material is sifted through a construction sieve.

It is recommended to pre-treat sawdust with an antiseptic or fire retardant solution. After drying, you can mix the insulation with a 10% lime solution and copper sulfate (or borax).

Sawdust as insulation: pros and cons

First of all, let's look at why sawdust is used to insulate a wooden house.
The main advantages of sawdust are their low price and excellent thermal insulation properties. In addition, this is a completely natural material, which cannot be said about more modern thermal insulators. This is important for allergy sufferers and families with children, as well as for people trying to minimize the presence of chemicals in the home.

After all, any modern materials release the substances they contain, and this can affect the health of the residents of the house.

Disadvantages include easy combustion and the fact that untreated sawdust can harbor rodents. These issues can be circumvented by treating sawdust with antiseptics - a solution of copper sulfate or boric acid. In addition, to improve properties, sawdust is mixed with other materials (clay, lime, cement, gypsum). The disadvantages of working with sawdust also include the rather labor-intensive technology of their use.

Supplement Options

Experts often add various components to the plaster to improve its performance characteristics.

The main materials for making the composition are clay, water, sand or sawdust. To increase the thermal insulation characteristics in the case of rough finishing, chopped straw or hay, hemp and flax fibers, shavings of pine, oak, alder, and dung are mixed into the mass. Among modern materials, polystyrene foam in granules or fibers has proven itself well.

Fillers for clay plaster

Asbestos

Fiberglass

Cement

In addition to the listed components, common additives for plaster are cement, asbestos, and fiberglass. These materials help improve strength characteristics. For decorative compositions, pigments and mineral fillers are added.

Insulation of bathhouse walls with clay

Thermal insulation of bathhouse walls from the outside using clay is done as follows:

1. The wall is covered with shingles, which are long slats 2-3 cm wide and 1 cm thick. The individual elements are fastened in the form of a lattice with wooden or galvanized fasteners. This is necessary to reinforce the clay layer.
2. Wet the clay with water. Add wood shavings, which will reduce the thermal conductivity of the solution.
3. Apply the mixture to the shingles and level with a special spatula. We use a plumb line or a building level to check the evenness.
4. After complete drying, we install sheathing on the walls and cover them with wooden siding or block house. Be sure to soak the facing material with an antiseptic before work.
5. A more budget-friendly option for exterior finishing involves whitewashing the clay layer with lime mortar.

Due to the increased temperature and humidity in the bathhouse, clay is not used for floor insulation. Under the influence of an aggressive environment, the material will become wet, crack and emit an unpleasant swampy odor. If you want to insulate your flooring with an environmentally friendly material, then consider expanded clay as an option.

Wall pie device

One of the most important factors when building a house is the correct design of the walls. It doesn’t matter whether you carry out all the construction work yourself, or order a ready-made option, in any case, you must know the correct composition of the “pie” of a frame house.

Layers of the correct “pie” of the wall:

1. Frame made of wooden beams.
2. There should be insulation between the racks.
3. Fiberboard (OSB).
4. Horizontal sheathing.
5. Insulation.
6. Multifunctional membrane.
7. Vertical lathing.
8. Finishing.
9. Vapor barrier.
10. Internal lining.

wall pie

Alternative option

If you use sawdust as wall insulation, you need to make a lathing.

First of all, you need to mount the frame. Then, at a certain distance, you need to attach wooden slats to the wall and lay the sheathing on them.

A little physics

Before delving into the technological aspects of using the product, let’s look at its physical and technical characteristics. And they are not too happy. Thus, the density of hardened clay is 1600-2400 kg/m3 (slightly less than that of concrete), and the thermal conductivity is 0.7-0.9 W/m°C.

It turns out that clay as a wall insulation is, to put it mildly, useless, so why is it still used?

The fact is that this material is an excellent binder, the strength of which is not affected in any way by the sucrose found in organic fillers (it is destructive for concrete), and this, in turn, opens up the widest scope for maneuver.

Characteristics of plaster

Clay plaster does not have high strength, but is actively used in construction. Its popularity was due to its high technical performance:

1. Thermal conductivity. The thermal conductivity of clay coating is W/m °C. Only the gypsum-perlite mixture is better. Thanks to this, the material perfectly retains heat in the room.
2. Vapor permeability. The parameter is responsible for removing moisture. For clay, the vapor permeability coefficient ranges from 0.1-0.15 mg/(m*hour*Pa). This is higher than the value of wood. Therefore, clay compositions are actively used for finishing log cabins.
3. Density. This parameter refers to the ratio of material mass to volume. For clay it is 1700 kg/m3. This is almost equal to the value of a brick.

When finishing 1 square meter with a layer of 1 centimeter, at least 15 kilograms of the mixture will be required.

Clay plaster has a high level of thermal conductivity, so it is often used for finishing surfaces.

Ceiling insulation

For work, it is advisable to use softwood sawdust. They are lighter than others and contain a natural antiseptic - essential resins. Heavier, but moisture-resistant, sawdust from deciduous trees is used to decorate the ceiling of a bathhouse or sauna.

Surface preparation

Work before applying a layer of insulation to the ceiling includes:

1. Cleaning the surface from dirt, debris and sharp elements that could damage the film of the insulating membrane.
2. Hemming the ceiling beams with dry (mandatory) boards. Its fastening is carried out with two screws in each place, or nails driven in at an angle. To ensure secure fastening, adjacent nails are driven in different directions.
3. Treatment of beams and cladding with fire-retardant impregnations.
4. Filling the remaining cracks with construction foam for installation.
5. Laying a layer of waterproofing.

The use of sawdust with cement

To prepare the mixture you will need cement and sawdust in a ratio of 1:10; 1 part of lime can be added. The amount of water is taken from the calculation of obtaining a mixture that does not crumble when compressed and liquid does not drain from it. Add 3 tbsp to a bucket of water as an antiseptic. l. copper sulfate. If you are insulating a wooden ceiling in a bathhouse, do not use vitriol - at elevated temperatures, harmful evaporation will be released from such a heat-insulating layer. The finished mixture is laid and compacted. After drying, a durable layer of lightweight concrete is obtained, which has good thermal insulation characteristics.

Using sawdust with clay

A mixture prepared from these components becomes an ideal filler and insulation for the ceilings of private housing construction, attic floors, and buildings for keeping animals (cow barn, chicken coop, etc.). Insulation of the ceiling with clay and sawdust takes place in two stages. The first stage is preparing a solution with large woodworking waste and laying it as a base 5-10 cm thick. The process of obtaining a raw mixture is standard. The laid out solution is compacted and a month is waited for it to dry completely. At the second stage, a mixture made from fine sawdust is prepared and placed on top. It is leveled flush with the wooden beams. After drying, cover up the cracks that appeared after drying.

The use of sawdust with lime and alabaster

The percentage of dry components in the mixture is 85:5:10 (sawdust: alabaster - building gypsum: lime). The mixed mixture is diluted with water in small batches due to the rapid setting and hardening of alabaster. This feature increases operating time, but the result is a durable coating that does not burn, is not a source of dust, and does not attract rodents. The mixture is laid out in a layer of up to 100 mm, its drying time is up to 4 weeks.

Insulating the ceiling with clean sawdust

With this method, the ceiling insulation is carried out from the attic or residential attic side. Dry sawdust treated with an antiseptic is poured to the top of the beams. The resulting layer is leveled without compaction and left for two weeks. Then the insulation is covered with a vapor barrier. For a used attic space, you need to make a wooden flooring with small gaps to ensure the necessary ventilation.

Preparatory work

How to insulate a ceiling with sawdust in a private house? Whatever method is chosen, preliminary preparation of the wooden base is required. Initially, the elements on the ceiling are processed. As a rule, during construction they use material that has already undergone appropriate processing. However, in some cases this procedure is skipped. Then you need to do it yourself.

The treatment is carried out with special protective compounds. It is carried out in several stages, since comprehensive protection is required. Initially, wooden parts are coated with antiseptic compounds designed to protect against rotting and insect damage. Next, fire-bioprotective agents are used, which increase the material’s resistance to fire and exposure to elevated temperatures.

For processing, it is recommended to choose drugs from the same brand. Some manufacturers offer products that perform several functions at once, for example, protect against fire and high temperatures, prevent rotting and insect damage. The bathhouse must be treated with special products that are resistant to high humidity and high temperature.

After processing and drying of wooden structures and ceilings, the substrate is laid.

Initially, all gaps and cracks should be sealed. To do this, use polyurethane foam and acrylic sealant. Large cracks are treated with foam. Gaps and joints are sealed with sealant. It is allowed to use bitumen mastic, but not for finishing the ceiling of a bathhouse. This is due to the low resistance of the material to high temperatures.

You need to seal not only the holes in the wooden ceiling, but also in the roof itself. This increases the thermal insulation properties and eliminates the impact of external factors on the internal elements of the roof.

After drying the sealant and foam and removing excess material, the substrate is laid. It is necessary to protect the interior space of a private house from the penetration of dust from sawdust, and serves as a vapor barrier between the ceiling and sawdust insulation. The substrate must be vapor-permeable, since warm air and steam rise up.

An excellent and inexpensive option is to lay cardboard. It can be any type of material. The main condition is that the cardboard must be dry. The sheets are laid directly on the ceiling, with an overlap of 15-20 cm on each other. If the cardboard is thin, then it should be placed in 2-3 layers. The joints are fastened with staples. The perimeter of the junction of cardboard and walls is treated with polyurethane foam or sealant.

PVC film is often used as a backing. It is also laid with an overlap of 10-15 cm, and additionally secured with staples using a stapler. The edges of the film around the perimeter should extend onto the walls/roof by 10-15 cm.

Adobe as insulation

Another interesting option for using clay is adobe. Previously, it served as the main structural material for the construction of walls, but today it is used only as insulation.

Here the filler is no longer sawdust, but straw. Again, an environmentally friendly product with excellent thermal insulation properties and, again, the purchase of which will not ruin your budget.

To acquire adobe, you only need to have a wooden mold and the desire to work. Kneading (clay and straw are kneaded with feet) is usually done right next to the clay quarry, where the resulting mass is filled into molds, and the blocks dry there.

The whole process is quite labor-intensive, but if this point doesn’t bother you, you can get a material with a thermal conductivity of 0.1 W/m°C, and this is already a pretty good indicator.

Recipe

If you are interested in clay with sawdust as insulation, the proportions here are simple. For three buckets of clay, take two buckets of wood shavings, mix it all and fill the space between the joists with the resulting mass.

You can easily not only walk on such insulation, but also dance, but you can’t call it too effective. Of course, the proportion of wood material can always be increased, but then the insulation will lose strength, which means that some kind of floor will have to be invented on top of it.

Comparative characteristics of clay with sawdust as insulation with polymer analogues

The environmental friendliness of expanded polystyrene and polystyrene leaves much to be desired; moreover, this group of heat insulators is extremely flammable. It should be remembered that sawdust in its pure form, not treated with agents that prevent ignition, is also a fire hazardous material.

Clay partially reduces the likelihood of ignition and fire spread. However, if power cables are laid near the insulation, you should take care in advance of their serviceability and the quality of the insulation. Thermal insulation of chimney pipes is also recommended.

Non-combustible materials include mineral wool, mineral wool and fiberglass, but they are distinguished by their ability to form dust when drying; their thermal conductivity coefficient on average does not exceed 0.42, which is half as much as that of a clay-sawdust mixture.

In terms of density, clay is a fairly weighty material. To achieve the desired thermal conductivity coefficient, it is necessary to lay a thick layer. Before starting work, you should make sure that such a load will be feasible for the supporting structure.

Experience shows that when insulating with synthetic polymers, costs are not limited to the purchase of material. The formation of condensation is one of the “side effects” of modern thermal insulators.

To maintain an optimal microclimate in the room, a vapor barrier layer is required, which means additional purchase and installation work. Choosing homemade insulation made from clay and sawdust can significantly simplify the thermal insulation structure and achieve the desired level of humidity in the room.

The advantages of synthetic insulation include ease of installation of some of them and high moisture resistance.

Polymers are initially not susceptible to rotting, and therefore do not require additional processing, their scope of application has no restrictions, while insulation made from a mixture of clay and sawdust is intended for internal walls and requires waterproofing: when wet, the thermal insulation performance decreases significantly, at the same time time, after drying the previous properties are restored.

Features of using sawdust as insulation, its advantages and disadvantages

Sawdust remains a cheap and effective means of insulating bathhouses and outbuildings

Sawdust is a waste product from the forestry industry, but it is an environmentally friendly material and does not emit caustic substances. Since ancient times, sawdust has been one of the oldest materials used as insulation.

Today, new types of insulation are replacing the material under study, but many continue to use it because they know its performance characteristics and its noticeable low cost.

Sawdust can be thrown in loose form into the wall frame

They are used to insulate the walls of small houses, bathhouses and gables in the attic. These waste products from the timber processing industry can be used at any stage of construction. It is not necessary to fill up the wooden dust or put it in bags on the frame; they can be thrown into the finished walls from above and compacted well. To increase the performance characteristics, sawdust is often impregnated with various antiseptic compounds, which prevents the appearance of insects in the insulation.

Advantages of sawdust

For many years, sawdust, as insulation, dominated among all types of thermal insulation. They were used in different forms. Some people poured clean wood scraps, others mixed sawdust with glue or cement, thus creating blocks with which they later laid out the wall. Over the years, this material has been used in various forms to insulate rooms.

Sawdust, like any other building material, has its advantages and disadvantages. The first group of characteristics includes:

1. Environmental friendliness of the material. The composition does not contain harmful components that could have a negative effect on the human body. If you intend to create blocks from sawdust, then for these purposes you can use clay and lime as additional binding components.
2. Low cost. Sawdust is often obtained free of charge at various wood processing enterprises. Costs may only be due to shipping and handling costs.
3. Long-term operation. Mankind, through long operational experience, has determined in what form it is best to use this material, therefore, before filling the walls, sawdust is specially moistened and dried several times. In recent years, antiseptics have begun to be added, thereby creating a barrier to the penetration of insects. Bags of silica gel are placed in the filled cells of the walls with sawdust to completely remove moisture from the heat insulator.
4. No special preparation required. Wooden waste is filled manually without the use of special tools and equipment. The material is filled in freely, after which compaction is performed.
5. Low thermal conductivity. Due to the fine fraction, this raw material has significantly lower thermal conductivity compared to boards or timber due to the absence of solid wood fibers.

Disadvantages of sawdust as insulation

A building insulated with sawdust should be used carefully

Unfortunately, this insulating material has more disadvantages than its analogues, but over a long period of existence, measures have been invented that allow minimizing all negative factors.

The disadvantages of sawdust as insulation include:

1. Increased fire hazard. Sawdust is a flammable material, but in order to partially avoid the problem and reduce the risk of fire, additional membranes made of tin or galvanized steel are created in the wall where the sawdust will be poured.
2. Attracts living creatures and fungus. Since sawdust is a natural product, it can harbor small rodents, insects and mold. Today, this problem can be easily solved with the help of appropriate drugs that are harmless to the human body.
3. The material shrinks. This drawback is significant, since it is not always possible to add material. It is for this reason that the sawdust is soaked several times before installation to make it heavy and to compact the entire composition as best as possible.
4. Fast moisture absorption. The material in question absorbs moisture well. To prevent this from happening, during operation it is hermetically protected with a vapor barrier and waterproofing film.

As you can see, all the main disadvantages of sawdust as an insulating material can be partially covered with the help of special preparations, materials and folk experience in using wood shavings.

Economical thermal insulation

The cost of building your own home (not to mention purchasing a plot for it) can put a dent in almost any budget. Therefore, in private construction, preference is often given to more economical options for materials.

The cost of modern insulation makes you think about how to save on this expense item when building a house. The simplest sawdust can be used for thermal insulation of a house, while the cost of this material will be minimal. You can purchase them at a very low price at any sawmill.

It is necessary to treat them with special compounds that can prevent this. In addition, it is also necessary to ensure their protection from rodents and fire. You can mix sawdust with clay, lime or cement. As a result, you will have insulation ready for use. It can be used to insulate roofs, floors and walls.

Useful forums

On the websites of stores selling building materials, it is very difficult to find real reviews and reports about insulating the walls of a house with sawdust, so we have prepared links to forums where users discuss various issues on this topic.

Some forums discuss the insulation of other parts of the house, but even there you can find a lot of useful information regarding the thermal insulation properties of sawdust and the features of their use.

Here is a list of these forums:

1. Forumhouse.
2. NGS house.
3. We are building a house.
4. House4U.
5. Vikag64.
6. Farmer's world.

Chock: birch or coniferous

Wood in houses built using Cordwood technology ranges from 40 to 60%. The rest is the solution and insulating mixture. 30 different types of wood are used, but softwood stumps are preferred: Pacific yew, juniper, bald cypress, cedars. Chunks of Douglas fir, western larch, pine, and poplar are also suitable. You can take alder and aspen, but not birch logs! Birch logs are the most unsuitable material for such projects; all stories on the topic “I built a house from birch logs” end sadly.

Before use, firewood must rest for a year, or better yet, three, otherwise significant shrinkage is possible (up to 10 cm).

Member FORUMHOUSE Metamorphos:

– Of course, the type of wood is important. As you know, oak only gets stronger from moisture

It is important how to treat the wood: stain (to enhance the color and texture), moisture-bio-fire protection, resin-based compositions (crystallize the structure of the wood, blocking the pores), as well as various waxes and varnishes (give the wood shine and water-repellent properties). At a minimum, end machining is required.

After it, the hut will have a luster.

Well-dried wood is prepared for construction: the bark is removed from the hemp, the end edges of the firewood are sanded to smooth out burrs that will accumulate moisture.

Before you start stacking firewood (or at least its ends), it is advisable to soak it with an antiseptic or burn it with a blowtorch.

Solution for laying firewood: choosing the best

Experts give various recipes for mortar for building with firewood. Here it is: 9 parts sand, 3 parts sawdust (preferably from softwood), the same amount of building lime, 2 parts Portland cement. For external waterproofing, silicate plaster and linseed oil are used. Another recipe suggests mixing 3 parts sand, 2 parts wetted sawdust, 1 part Portland cement and 1 slaked lime.

Some builders plant firewood on a mixture of clay and sand or straw. The name of this “clay” technology is “clay mortar”.

Houses made of clay, photo. Projects in Russia.

According to FORUMHOUSE member Vatar, it is undesirable to do this:

“It was our Kulibins who began to make clay mortars, sculpt them from clay, and then scrupulously cover up the cracks every year. I know from my own experience working with clay mortar how difficult it is to choose a composition with the least amount of cracking. In addition, the clay for the solution must sit outside during the winter. Alternatively, you can experiment with the composition clay-lime-sand-sawdust, and the ratio of clay to sand should be no more than 1 to 4.

If the gazebo is made of logs and clay, processing the ends with a blowtorch will be more organic.

Gazebo made of logs and clay, processing of ends.

Sawdust with lime (or a mixture of sawdust soaked overnight with vermiculite), polyurethane foam, fiberglass, cellulose, and polystyrene are used as an insulating layer when building a block house.

Metamorphos forum user suggests this solution:

– To reduce the thermal conductivity of cement, you need to knead foam concrete (perlite concrete, expanded clay concrete, or, at worst, sawdust concrete), use various additives in the form of lime, PVA glue (this will ensure a reliable bond between the cement and the wood), and all sorts of plasticizers. It would be good to tint the concrete with pigment at the mixing stage, because the whitish-gray color does not look very good with wood. As an option, during laying, concrete is placed in the inner layer (about 15 cm), and the outer layer (the same amount) is filled with two-component polyurethane foam with a density higher than 35 kg/cub.m. This will provide the necessary strength, the absence of cracks when drying and good thermal insulation, and the yellowish color of the polyurethane foam in this case will not spoil the appearance.