In addition to cost, sawdust, as insulation, has many other useful properties. We will try to note all their advantages in order to more accurately understand the possibility of their use in the insulation of buildings.
Insulation of a frame house with sawdust is one of the uses of this environmentally friendly material, which is characterized by low cost and availability, especially in regions where woodworking is organized on an industrial scale.
House insulation with sawdust
- Features of use
- Advantages and disadvantages
- Choice of materials
- Preparatory work
- Performance of work on insulation using sawdust
- Filling internal cavities
- Laying on the frame
- Thermal insulation of walls with plaster
- Block assembly
Sawdust is a cheap natural material used in the manufacture of building materials for various purposes (sawdust concrete, wood-sawdust boards, etc.), as well as environmentally friendly energy sources (fuel briquettes, and fuel pellets).
Features of use
Sawdust is a waste of woodworking industries, so their cost is low, and often completely tends to zero.
In regions where there are no factories for their processing, and wood harvesting and its processing are engaged in small volumes (small sawmills, small furniture shops), the sawdust is simply disposed of or given to summer residents and gardeners absolutely free.
Sawdust has been used in construction for a very long time and initially their main purpose was to serve as a heater for ceilings and fillings (pick-up or basement in a modern house).
The main feature of this material, which must always be taken into account, is that it is a fire hazardous, combustible material that promotes the spread of flame.
Advantages and disadvantages
Like any building material, sawdust has inherent pros and cons, which determine the possibility of their use in one quality or another.
The advantages, if used as insulation, are:
- Environmental Safety.
- Low cost.
- Long service life.
- Ease of use, which does not require the involvement of sophisticated technology and special equipment.
- Low thermal conductivity.
The disadvantages are:
- It is a fire hazardous material.
- Promotes the formation of mold and mildew in case of excessive moisture, and also serves as a habitat for insects and rodents.
- When laying, tamping is required, but, nevertheless, during operation it still shrinks.
- Potential for significant moisture absorption.
- The ability to absorb moisture negatively affects the surface to be insulated and the insulation itself, which loses its technical characteristics (thermal conductivity).
The performance of work on the insulation of building structures and individual elements of buildings and structures using sawdust as an insulating material can be divided into several stages, these are: the choice of materials, preparatory work and the implementation of insulation work.
Choice of materials
When choosing and sorting sawdust, you need to pay attention to the following indicators, such as:
- The size. This indicator characterizes the thermal conductivity of sawdust of one size or another. Large – are able to create a larger volume, forming a significant air gap. They are suitable for a rough layer of insulation. Small – have the best thermal conductivity, but are not convenient to use, because dusty when used. Medium – serve as a good filler in the preparation of mortars and concretes.
- Humidity. The presence of moisture negatively affects their thermal conductivity, therefore, for use as insulation, it is necessary to use dry material. In production, as a rule, as a result of wood processing, raw sawdust is obtained. round timber is processed without preliminary drying. Therefore, before use, they must be dried by spreading them in a thin layer in a warm room or outdoors under the sun. At woodworking enterprises using dried material in their work (furniture production, door manufacturing, etc.), the sawdust is already dry, so there is no need to dry it.
It is not recommended to use sawdust prepared from the bark of trees and waste from furniture industries using chipboard, MDF, OSB and other materials based on any binding elements as a heater.
At this stage of the work, the following activities are carried out:
- the surface to be insulated is cleaned of dirt and foreign objects that can damage the waterproofing (installed in the future);
- wooden structures are treated with antiseptic solutions and fire-fighting compounds;
- if there is damage on the surface to be insulated, then they are repaired. For this, sealants and building mixtures are used that correspond to the material from which this surface is made;
- the installation of a waterproofing layer is carried out, ensuring that moisture does not penetrate from the outside into the insulation layer (in sawdust). sawdust is prepared for further use.
When preparing sawdust, it is necessary to consider in what quality they will act. So when used in their pure form, they are dried, after which they are laid.
To protect against rotting, fungus and rodent damage, sawdust can be treated with special substances (copper sulfate, slaked lime and other chemical reagents), in which case drying is performed after such treatment. Also, at this stage of work, large fragments and remnants of wood are removed, which are always present in sawdust.
When using sawdust as a filler for concrete and mortars for various purposes, drying and processing with chemicals (reagents) are not performed.
Performance of work on insulation using sawdust
There are several technologies for using sawdust for insulating building structures, these are:
- Dry technology. With this technology for performing work, sawdust is poured dry onto the insulated surface, while the larger fraction is poured into the lower layer, and the smaller one – into the upper layer. This is especially true when insulating floors, interfloor floors and roofs. The lower layer creates an air barrier in the insulation layer, and the upper one provides the required thermal conductivity for it. When laying, the sawdust layers are compacted, after which the finishing of the insulated surface is performed.
- Using cement. In this case, sawdust acts as a filler in the preparation of a sawdust-cement mixture. The mixture is prepared from sawdust, water and cement in a proportion of 20/3/2 of the volume, respectively. First, sawdust is mixed with cement, then water is added and the solution is thoroughly mixed.
- Using clay. With this use case, clay is initially taken and filled with water for swelling. When the clay swells, it is mixed with sawdust until the consistency of a thick solution is uniform, after which the mixture is ready for use.
After the preparation of sawdust or a mixture based on them, the insulation of cats for use is applied to the elements of insulated structures.
Filling internal cavities
With the frame construction technology, the insulation is laid in the inner space of the frame, in its cavity. In this case, various types of heaters are used, including sawdust, while their main advantage, in relation to other heaters, is their availability and low cost.
Dry technology is used to fill the interior space.
The frame is sewn on both sides to a certain height, while from the inside it is sewn with a layer of hydro and vapor barrier. The vapor barrier is located on the inside of the wall, and the waterproofing is on the street side.
Sawdust is poured into the inner cavity of the frame and rammed. In the upper part of the wall, a place is left for filling the sawdust after shrinkage. When the sawdust settles down, the finishing of the insulated room is performed.
Laying on the frame
Insulation of the frame on its surface is another way to insulate a frame house.
On the surface of the wall to be insulated (inside or outside), a supporting frame is mounted to ensure the strength of the structure under construction. The width of the guides must correspond to the thickness of the insulating layer, and a reinforcing mesh is mounted on the surface, in the case of a vertical arrangement of the insulation.
In the manufacture of the frame, a bar or a metal perforated profile made of galvanized iron is used.
For fastening the profile to the surface of the wall and its parts, shaped elements (corners, plates, etc.), as well as self-tapping screws and expansion dowels, are used.
For the preparation of sawdust, a technology using cement is used.
The prepared cement-sawdust mortar is placed on the mounted frame, while, in order to prevent the mortar from flowing, it is applied in small volumes, up to 30.0 cm in height.
When laying, the solution is rammed. After hardening, the laying of the next level continues, and so on until the work is completed on the insulated surface.
Thermal insulation of walls with plaster
This version of the work is performed using clay technology.
Initially, like the production of work using other technologies, the surface to be insulated is prepared and an appropriate solution is prepared.
On the insulated surface, a crate is mounted in the form of two rows of jumpers, closely spaced from each other. The thickness of the insulation in this case will be determined by the size of the crate (thickness of 2 rows of slats).
The solution is thrown into the crate and rubbed, and after it has solidified, the following types of work are performed: waterproofing, sewing and finishing.
Another way to insulate a house using sawdust is to make blocks on their basis, laid on the insulated surface.
In the manufacture of blocks based on sawdust, a technology using cement or clay can be applied.
For the manufacture of blocks, forms are used that determine the dimensions of the resulting product, as a rule, it is 50x50x100 or 70x70x100 mm. For regions with cold climates, the dimensions may be increased.
The prepared solution is placed in a mold, and after hardening, it is removed from it. Further drying continues in the shade, without contact with sunlight.
After the number of prepared blocks is sufficient to insulate the house, they are installed on the insulated surface. Sawdust blocks are laid in the same way as brick or foam blocks are used.
Warming a house made using a frame or other technology using sawdust is a significant reduction in the cost of the entire complex of construction and installation work, moreover, such work can be done by hand without the use of complex special equipment. published by econet.ru
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