In the forest regions of Russia, Scandinavia, Canada and North America, log houses have long been built. Logs or timber are sequentially stacked in rows in rows called crowns.
Interventional insulation is an important component of such a construction technology.
What is it for?
The preparation of a tree trunk for use as a wall material is now carried out by machining on special machines. Logs are cylindrical by turning and have a perfectly round cross section along the entire length. A profiled glued beam, which has special grooves for a more tight connection, is considered the best material for walls made of solid wood. But in this case, there is the possibility of blowing walls through horizontal seams between the crowns.
Wood is a living material. It is the unique natural qualities of wood that make the chopped house atmosphere so valuable. But hence the main disadvantages of wood as a building material. It is subject to shrinkage and deformation under the influence of seasonal changes in temperature and humidity, from the difference between the internal microclimate of the building and atmospheric conditions, from multidirectional loads experienced by different parts and structures of the house.
To prevent possible heat loss and compensate for the inevitable deformations, an interventional heater is also needed.
The function determines the quality
The interventional heater should have the necessary properties.
Sufficient density and elasticity are necessary to eliminate the formation of cracks during operation of the house. It should not crumple from a vertical load and fill the resulting voids.
Low thermal conductivity is needed to protect against heat loss. The ability to absorb excess moisture from the air and release water when it is lacking is one of the advantages of wood. Interventional insulation should also have vapor permeability, so as not to reduce the comfortable quality of wood. Hence the increased requirements for environmental friendliness. The isolation of harmful substances or allergens by a heater will negate the beneficial effect on the human body of the natural environment of a wooden house. The creation of an environment for the development of harmful microorganisms is also excluded.
Closely linked are durability and profitability. The need for frequent replacement of insulation and repair of joints will lead to unnecessary expenses during the operation of the house. For decades, only high quality material can not change the physical and mechanical properties and chemical composition. Biostability is important, that is, the interventional insulation should not rot and mold, should not become food for birds, rodents, moths, etc.
In the beginning there was moss
Moss with long fibers (red moss, sphagnum, cuckoo flax) is a traditional material for warming log houses in Russia. Its excellent qualities - low thermal conductivity, the ability to absorb and give off moisture depending on the humidity of the surrounding air, bactericidal properties - it is difficult to reproduce in artificial materials. The main drawback is the difficulty in organizing industrial procurement and difficulties in laying.
Material based on plant fibers is the best interventional insulation. Especially when it is specially prepared for laying on logs or timber. Flax fiber, hemp (hemp fiber) have long been used in the form of tow for insulation and caulking of joints. Modern manufacturers pass them through carding and needle-punching machines and offer easy-to-use rolled up strips of linen felt and ribbon tow.
In this form, jute interventional insulation is supplied to the construction market. It is based on raw materials of plant origin, supplied to Russia from the countries of Southeast Asia and Africa.
Not all fibers of natural origin can be used as an interventional insulation for timber or logs. Cotton or wool batting, felt are absolutely not suitable for this purpose. In addition to low density, they strongly absorb water, and moth inevitably starts in the wool.
Mineral and synthetic
In modern construction, for the insulation of walls, ceilings, ceilings, roofs, many materials are used in the form of mats, blocks, rolls, aerosols, etc. They have excellent indicators of thermal protection and moisture resistance, but are completely unsuitable for use in wooden housing construction.
The main reason is the complete non-compliance with the requirements for vapor permeability. Insulators based on glass wool and basalt mineral raw materials are compressed under the weight of the crowns. Air from the space between the fibers is squeezed out and an impenetrable barrier forms for water vapor contained in the air and in the wood itself. In addition to the deterioration of the microclimate of the home, excess moisture condenses at the border of the tree and the insulation and gradually destroys the massif of the wall. In winter, moisture accumulation places freeze and the process of structural destruction is accelerated.
There is no ventilation for porous polymeric materials. Expanded polystyrene, foamed polyethylene, rigid polyurethane foam, foam rubber, mounting foams, sealants and their combinations cannot be used as an interventional insulation. In addition to wasting money, you can get a home that is unfit for life and loses strength.
Exotic guest
In addition to flax and hemp, there is another plant fiber. The jute interventional heater is gaining popularity. Jute is a plant fiber extracted from the eponymous annual shrub growing in the subtropical regions of Asia and Africa. It belongs to the spinning (bast) plants of the linden family. In scope it is similar to flax and hemp (technical hemp), but it has some qualitative differences.
Both linen and clothes are made from flax, and from jute - a technical canvas for containers and ropes. Compared to other plant fibers, jute fibers are more coarse and brittle. Experts attribute this to an increased content of lignin in jute. This is a natural high molecular weight polymer that causes lignification of plant cells. In jute, pectin and wax are almost absent, giving elasticity and flexibility.
The elementary fibers forming a jute strand are much shorter in length than flax and hemp. Hence the increased hygroscopicity (the ability to absorb moisture), because the capillaries formed in the fiber are, in short, easier to saturate with water.
Advantages and disadvantages of jute insulation
An interventional insulation made of jute fiber is made in the form of tow or felt tape 5 - 15 mm thick. Tow is better suited for a wall of logs or beams prepared without the use of calibration on machines. Insulation strips conveniently fit on the rows of logs and profiled glued beams. It is convenient to fix the tape with a stapler, smooth edges do not require additional caulking of joints, it is convenient to make mounting holes for pins, etc.
The physicotechnical qualities of jute fiber are determined by the pros and cons of the interventional insulation made from it. Jute gives it a density that is uniform throughout its length, resistance to decay, and durability. Increased hygroscopicity can become a lack of material: excess moisture accumulated in the insulation can lead to freezing of the wall. Inadequate ductility can lead to the formation of voids in the joints between logs or timber.
Approximately 2% of the cost of building a house goes to interventional insulation. The price of a running meter of a strip of flax with a width of 20 cm with a thickness of 8-10 mm averages 6 rubles. A similar insulation from 100% jute - 12 rubles. Jute is an imported product, its cost is higher than domestic flax raw materials.
The best choice
The practice of professionals in wooden housing construction shows that a strip of needle-punched felt made from a mixture of linen and jute fiber is the best interventional insulation. Jute adds elasticity and durability to flax insulation. The proportion of jute fibers can be 10-50%. It is important to remember that the use of secondary raw materials (recycled jute bag packaging) significantly affects the quality of the insulation.