Wood is one of the most common building materials in the world. It is widely used for both building construction and interior decoration, due to its strength, durability and excellent aesthetic characteristics. Because it natural material, it is subject to biodegradation under the action of moisture and microorganisms, so it is important to prevent the putrefactive process. How and what is the treatment of wood from decay?
Causes of decay
The main enemy of wood is a fungus that causes it to rot. "Contamination" can occur as a result of improper storage and transportation. Active reproduction of microorganisms provokes a whole set of concomitant factors:
- Increased air humidity - up to 90%.
- Stagnation of oxygen.
- Moisture exposure.
- Temperature fluctuations and freezing.
- Prolonged contact with the soil.
Prevention of wood decay
To prevent the appearance of mold even before the start of construction, there are many preventive measures. Since the moisture content of a tree after a felling varies from season to season, it must be dried in natural conditions for at least 1 year.
There are a number of methods to prevent biodegradation processes and the negative effects of moisture:
- Waterproofing.
- Staining with special compositions.
- Roof waterproofing.
- Heat and vapor barrier.
The foundation for a wooden structure should always be located above ground level, it is also necessary to equip a drainage system and blind areas. Garden near the house with tall trees - bad idea as they will prevent natural drying.
Also, to prevent putrefactive processes, it is necessary to inspect the house every year. If signs of fungus are detected, the material should be taken for a sample to determine its moisture content and density.
Preventive measures are important, since many physical indicators decrease in wood affected by the fungus: it becomes up to 30 times less hard, 3 times less dense. All this leads to distortion window openings, the movement of the walls, up to the loosening of the structure.
Once biodegradation has begun, it can be contained with special means- both store and folk.
Antiseptics
If mold has already appeared, then its growth can be prevented with the help of antiseptic agents. They suppress reproduction wooden surfaces microorganisms that cause putrefaction.
Today, the store usually has something to choose from antiseptics When choosing a specific product, attention should be paid to indicators such as possible harm to humans and animals, anti-corrosion properties and impact on the quality of the tree.
All antiseptics are conditionally divided into 3 groups:
- Water soluble agents.
- Oily.
- Pasty.
Water-soluble antiseptics
The most common impregnation is sodium fluoride. Its popularity is due to a set of significant advantages:
- high efficiency;
- good penetrating ability;
- no unpleasant odor.
Sodium fluoride does not impair the aesthetic properties of wood and does not cause corrosion of metal parts that come into contact with it. In order to protect the tree from decay, BBK-3 and GR-48 are also often used.
BBK-3 is a solution of borax and boric acid. It is relatively safe for humans and animals, and also has excellent penetrating power.
GR-48 is a drug based on pentachlorophenol. It protects the boards not only from the negative effects of moisture and biodegradation, but also from blue.
Often, products are used that contain several active ingredients at once - for example, HTC based on chrompic and zinc chloride. However, this impregnation has 2 significant disadvantages: toxicity and the possibility of wood staining.
Oily and pasty antiseptics
Oily antiseptics are considered the strongest of their kind. They are used to protect wooden walls from the negative effects of moisture and soil. However, oily impregnation also has two serious drawbacks: a sharp bad smell and the ability to stain wood in a dark brown color.
Paste antiseptics consist of three main components:
- Water soluble antiseptic.
- Filler.
- Clay or bitumen as a binder.
Organically soluble antiseptics are products like PL containing pentachlorophenol and petroleum products. However, due to their high toxicity, they are rarely used.
The use of organically soluble antiseptics is justified for treating wood when exposed to moisture in order to avoid drying. Using these tools, you need to take care of personal protection: gloves and a respirator.
How to impregnate wood
In order to treat the tree with an antiseptic composition, use different methods. Most effective way immersion of the material in baths with the active substance is considered. The only disadvantage of the method is its high cost.
The second method is impregnation using autoclaves. This method is based on the effect high pressure, which contributes to the deep absorption of the composition into the material.
Often, special pastes are applied to the boards - they have good penetrating power and effectively protect the material from fungus. Often, antiseptics are applied with rollers, brushes, or simply sprayed from a spray bottle.
Applying an antiseptic with a brush, as well as a spray gun It is always necessary to apply the composition on a dry surface that has not been varnished or enameled, since in these cases the product will not be able to be absorbed.
The first step is to treat the areas where rotting has already begun. Usually these are the ends of the building and sections. It is best to carry out the procedure at a temperature of +20 to +25. If the temperature drops below +5, treatment with an antiseptic will not work.
Folk remedies for impregnation
If the putrefactive process did not have time to grow strongly, folk remedies will help prevent further destruction of the tree:
- silicate adhesive.
- Soda and vinegar.
- Potassium bichromate solution.
- Copper vitriol.
- Resin.
- Salt and boric acid.
The easiest way is to use silicate glue. It is required to dilute it with water, and apply the resulting solution to areas where biodegradation is observed. You can also treat the places of decay with soda, and sprinkle with vinegar from the spray bottle on top.
Potassium bichromate is used by mixing in equal proportions with sulfuric acid. The resulting composition should be processed not only on the boards on the street, but also up to 50 cm of the soil layer.
Another effective handy tool to prevent wood decay blue vitriol. To prepare the composition, take 100 g of the substance per 10 liters of water.
For outdoor processing resin can be used, as well as a mixture of 1 kg of salt and 50 g of boric acid, which are stirred in 5 liters of boiling water. Such a composition must be applied to the wood several times, waiting for a couple of hours so that the product can be absorbed.
Processing by the Finnish method
The Finnish method is a special way of processing wood to protect it from moisture and decay. You will need a set of ingredients:
- salt;
- flour;
- water;
- slaked lime;
- inkstone.
Such a composition is kept on the material for a very long time, without being washed off with water. Despite the safety of the method, it is recommended to use it only for the protective treatment of wood intended for fences and roofs.
The listed ingredients must be mixed to a consistency resembling sour cream, and the bulk of the mixture should be based on flour and water. After thorough mixing, the composition should be slightly heated over low heat, and when it becomes warm, you need to quickly apply it to the boards.
After the first layer has dried, it is necessary to process the material again. If the composition has cooled down by this time, it will need to be heated again.
Wood is the one building material, which has high thermal and mechanical properties. Valuable structural qualities - light weight, strength, industrial production of building parts, transportability - determine the economic feasibility of using wood in construction.
However, wood also has one big disadvantage: under certain conditions, it can be destroyed by biological agents (insects and wood-destroying fungi). In addition, wood-staining and mold fungi can appear on wooden structures. These organisms do not destroy wood, but can significantly damage it. appearance.
So, mold fungi stain the wooden surface in an unpleasant dirty green color, and wood-coloring fungi - in yellow, blue, brown, reddish, etc. Especially often blue appears on the tree, which is also a sign of damage by wood-coloring fungi.
As a rule, it appears on sapwood when raw wood is stored in warehouses, delayed drying, or in ready-made houses from insufficiently dried or damp logs (see Figure 1).
Figure 1. The manifestation of blue on wall logs
Blue can affect wood of any species, most often conifers. Blue fungus infestation starts from the surface. Penetration into the wood occurs along the core rays. For example, on the rounded ends, the blue forms radial wedge-shaped spots, sometimes there is a continuous color of the sapwood (see Figure 2). In lumber and on the side surfaces, elongated spots and stripes of blue are observed.
Figure 2. Damage to the blue sapwood of a pine wall log
The optimal temperature for the reproduction and growth of blue fungi is considered to be 20-25 degrees, at 7-8 degrees the growth of the fungus slows down. As for humidity, the range of 33-82% is considered optimal, but wider limits are possible (from 22 to 163%).
Blue-stained wood usually has an increased rate of water absorption. After the influence of blue fungus on wooden structures, the rate of water absorption of the sapwood of a pine wall log increases one and a half times for a month.
Wood affected by mold fungi does not actually change its technical properties, however, the spoiled appearance reduces its value. Mushrooms of blue and mold are the primary complex of destroyers, which, with a long exposure, create a favorable environment for the further development of house fungi, which are especially dangerous for wood.
Wood-destroying mushrooms cause great damage to the wooden structures of structures and buildings, sometimes completely disabling them. Such damage is associated with the settlement and development of house mushrooms in wooden structures. To date, more than 70 species of such fungi are known, and many of them are capable of causing local damage. They destroy wood rather slowly and are not of great practical importance.
Wood decay is natural process decomposition, which is characteristic of any dead plant. The decomposition of wood occurs due to wood-destroying fungi. These are lower plant organisms that penetrate deep into the wood and use its constituent parts for their development.
At favorable conditions spores (germs of the fungus) begin to germinate, turning into hyphae, that is, fungal threads.
Enzymes secreted by developing fungal filaments partially dissolve the walls of wood cells. They are used by fungi for growth and nutrition. This is how rotting occurs - the biological resolution of wood.
In the initial stages of decay, the wood does not change its appearance, so the presence of fungal filaments can only be detected under a microscope. Later, the wood becomes reddish or yellow, then brown and brown, its strength and density gradually decrease, it loses viscosity, becomes soft and light. At the last stage of decay, transverse and longitudinal cracks, along them it will break up into separate prisms. By properties, this wood is similar to charred: with light pressure, it is ground into powder. This type of rot is called destructive. It is typical for house fungi that destroy structures in structures and buildings (see Figure 3).
Figure 3. Merulius lacrymans (Fr.) S.F. Grey:
a - mycelium; b - young fruiting body;
c - old fruiting body; d - view of the old mycelium, rot and wood cords
Mandatory conditions for the development of wood-destroying fungi are:
- Sufficient wood moisture (more than 20%)
- Availability of food
- positive temperature.
If either of these conditions is absent, the development of the fungus will be delayed, even if it is rooted in wood. The humidity and temperature of wood, which are needed for the growth of house mushrooms, are given below.
Table 1
| Type of house mushroom | Temperature, °C |
Wood moisture, % |
||
| minimal | optimal | maximum | ||
| Real | 8 | 23 | 27 | 20 |
| White | 5 | 27 | 37 | 35 |
| Filmy | 8 | 23 | 37 | 50-60 |
Most great harm The following types of mushrooms can cause wooden structures: white brownie, real white brownie, membranous brownie.
To combat wood decay, various means are used: chemical measures protection, which are based on the use of biologically active substances and preparations. They are able to prevent the development, weaken or stop the vital activity of organisms that cause damage, sometimes to complete destruction, of objects, individual structures or materials.
Protecting a wooden house from biodegradation can be done chemicals and drugs called antiseptics.
Depending on the service conditions of the impregnated material, its purpose and variety protective composition It is customary to use two different types of impregnation in construction:
- Antiseptic when the composition is applied to the surface. This ensures the penetration of the impregnation into surface layer wood 1-2 mm deep
- Preservation or deep impregnation, in which the applied composition penetrates to a depth of about 2-3 cm or more.
If protection of a wooden house from biodegradation produced by antiseptic chemicals have a short-term toxic effect on destroyers. When preserved, antiseptics have a long-term toxic effect on destroyers.
The bulk of wooden structures used at construction sites, as well as at wooden housing construction enterprises, are treated with antiseptics using surface application.
Deep impregnation is mainly used in woodworking shops of enterprises and impregnation plants.
You can buy wood protection products from the Skolt manufacturer, in general, antiseptics have a fairly extensive range, and you can pick them up individually at the request of each client. This diversity is caused by different operating conditions of wood, the availability of chemical resources, the availability of chemical resources, economic and safety requirements.
The following are tips for choosing antiseptics that will provide preventive protection of a wooden house from biodegradation. It can be used in residential buildings, garden houses, cottages.
Overlappings
In residential buildings, three types of floors are used: interfloor, basement, attic. For interfloor and basement floors, sources of moisture are common - leaks due to malfunctioning plumbing fixtures and household moisture.
Ground floors
The humidity of wooden structures in the underground is influenced by the level of soil moisture under the building. At impervious soils, where there is surface water, as well as in wet soils that are permeable, strip foundations are in a wet state. This causes capillary moistening of the soil base of the underground and masonry. brick plinth. If the strip foundation is solid and the soil moisture is high, the air humidity in the underground also increases. This leads to the settlement and development of wood-destroying fungi on the floors.
Moisture that evaporates from the ground can be removed from the underground with the help of products that are arranged in the basement. This allows you to provide a normal humidity regime for the structures of the basement.
In the first half of summer middle lane the concentration of water vapor in the underground is actually no different from the concentration that is in the outside air. At this time, there is practically no diffusion exit of moisture from the underground.
In this period, there can also be no removal of moisture by the air flow, which occurs only with gusts of wind, since the moisture content of the air underground and outside is almost the same. It is at this time that the processes of decay of wood take place.
As a rule, a warm basement floor is arranged above the cold underground, and the load-bearing beams are most often placed inside the floor between the floor and the firmware. They can also partially go into the underground space (for example, when arranging along the cranial bars of the black floor).
In any case, it is necessary to take into account the possibility of the appearance of wood-destroying and mold fungi on the wood. You should also take into account the complexity of monitoring the condition of the wooden floor. That is why before the installation work it is recommended to treat all floor elements with antiseptics - beams, girders, subfloor boards and boards, finishing floors and logs (see Figure 4). With special care, it is necessary to antiseptic those elements that are in the thickness of the ceiling and are not subject to regular visual observation (see table 2).
Figure 4. Basement over beams and outer wall from roundwood:
1 - ventilation air; 2 - gasket for thermal insulation (tarred tow); 3 - crown crown; 4 - beacon rail after 60 cm; 5- boards outer skin; 6 - flooring boards; 7 - logs; 8 - insulation; 9 - bearing beam; 10 - vapor barrier; eleven - support boards; 12 - black floor boards; 13 - support lining; 14 - a column of concrete or brick; 15 - cranial bar; 16 - waterproofing; 17 - blind area
To perform antiseptic treatment, it is recommended to buy BIODECOR or BIODECODER-M. These antiseptics are highly effective against wood-destroying and mold fungi, blue stain, insects, and have increased resistance to leaching. Antiseptic BIODECOR-M does not corrode non-ferrous and ferrous metals. If you buy BIODECODER-M and process wood with it, it will acquire a pleasant light green tint. When using the BIODECODER, the wood is stained chestnut. These antiseptics do not hide the texture of wooden structures and are odorless.
Interfloor floors
Most often, the reason for the decay of wooden structures of interfloor ceilings is the use of raw wood, the lack of proper conditions for drying.
The ends of the beams located at the points of their contact with the outer stone walls (gas silicate, brick, foam concrete, etc.) are especially dangerous in beam-type ceilings. They can be moistened by condensation that forms in winter time on back wall nests due to inflow warm air from the room, as well as installation moisture.
Multiple inspections of buildings with wooden floors have shown that the ends of the beams located in the outer walls can be destroyed due to decay or damage by insects, fungi (Figures 5 and 6).
Figure 5. Wood that is destroyed by woodworm and wood-destroying fungus (bearing part of the floor beam)
Figure 6. Destruction of the edge of a wooden floor beam by a house mushroom (a), rolling plate (b)
When the beams come into contact with the outer stone walls, blind sealing of the edges of the beams is widespread (Figure 7).
Fig.7. Blind embedment of the beam in contact with the outer wall:
1 - floor beam; 2 - wall of the structure; 3 - the surface of the beam, which is to be treated with an antiseptic; 4 - moisture-proof bandage; 5 - plaster for thermal insulation; 6 - waterproofing; 7 - foam for mounting; 8 - wooden lining treated with an antiseptic; 9 - waterproofing layer
When antisepticizing, the end of the beam must be beveled at an angle of 60-75 degrees, then the end of the beam, including the end itself, should be treated with a substance for a length that exceeds the depth of the structure by 15-20 centimeters. Based on the fact that the supporting part of the beam is exposed to drop-liquid moisture, BIODECOR-M, which is difficult to wash out, is used for processing.
The butt should be especially carefully protected, since it is most often exposed to decay. The structure is treated with an antiseptic until completely saturated, that is, until the moment when absorption stops. Then the treated surfaces, except for the end, must be protected from moisture with the help of pasted waterproofing (you can use stekloizol, hydrostekloizol, etc.).
Those surfaces of the beams that are in the span are operated in more favorable conditions than the ends in contact with the stone walls. However, it must be taken into account that during operation water may get on them. These can be accidental leaks as a result of a breakdown in the sewer or plumbing system, heating devices etc.). That is why their antiseptic treatment is appropriate. For this, an antiseptic DOMOVOI can be used. This drug has a high diffusion capacity. It penetrates deep into wood with high humidity, which allows the product to be used to protect damp or poorly dried wood. After treatment with this tool, the wood retains its texture and does not change color. It is important that DOMOVOI does not corrode ferrous metals, therefore, contact of the treated wood with metal structures, details.
Antiseptic preparations KRAM-S and KRAM can also be used for billet protection treatment of various wooden floor elements. They are intended for impregnating wood, which is not subjected to condensation moisture during operation (see table 2). These antiseptics provide multifunctional protection for wood structures, including help against biodegradation, provide preventive protection against insects. KRAM-S does not change the color of the wood, but KRAM stains it light brown.
Attic floors
When installing ceilings on beams, it is necessary to perform the same measures to protect the edges of the beams as when installing interfloor ceilings (this can be treatment with a BIODECOR-M antiseptic with further waterproofing of the protected side surfaces).
Figure 8. Contact points of attic floor beams and rafters on the outer wall
1 - window / door frame;. 2 - outer wall; 3 - plaster for thermal insulation; 4 - surf; 5 - sheathing material for the overhang of the eaves; 6 - crate; 7 - roof sheets; 8 - rafter leg; 9 - filly; 10 - Mauerlat beam; 11 and 12 - waterproofing; 13 - supporting edge of the beam; 14 - bearing beam; 15 - blind embedment with cement; 16 - vapor barrier; 17 - insulation; 18 - rolling boards; 19 - cranial bar; 20 - filing boards; 21 - lining
You also need to consider measures to protect wooden floors from moisture precipitation that penetrates into the attic through roof holes, as well as condensate that forms due to freezing in the thickness of the floor.
Through the attic floor, in the same way as through another external fence, water vapor diffuses from the premises to the attic. That is why, in order to protect the insulation from moisture from indoor air vapor, it is necessary to protect it with a vapor barrier layer on the “warm” side (Figure 8). High-quality heat and vapor barrier will not only provide the necessary thermal protection, but will also significantly increase the durability of the rafter and roof material. If the vapor barrier is missing, the installation is damaged or poorly done, water vapor can penetrate through the ceiling into the attic, drain onto the wooden stacks. As a result, corrosion of metal parts and ceilings develops, the destruction of rafters and roofing carpet.
In case of violation of the tightness of the vapor barrier layer, the insulation is moistened and, accordingly, the heat-shielding characteristics of the floor are reduced. Those floor elements that should be treated with an antiseptic are shown in Table 2.
To protect floors from biodegradation, antiseptic treatment with antiseptics DOMOVOI, KRAM-S, KRAM can be used as a preventive measure.
Elements truss system(picture 8)
The safety of rafters, trusses, racks, purlins, Mauerlats and other elements of the truss system largely depends on the temperature and humidity conditions that are available in the attic. It can be heated (attics) or cold (unused).
Cold attics
In winter, air with a high moisture content penetrates through leaks in hatches and doors from living quarters to the attic. This causes intense condensation on the elements of the truss system and cold roof surfaces.
It is necessary to pay special attention to the condition of the roof. Sometimes barely noticeable damage to the roof can eventually lead to the destruction of the supporting structure as a result of decay (Figure 9).
To prevent biodegradation of the elements of the truss system, it is recommended that they be antiseptic with BIODECOR-M, KRAM-S, KRAM preparations. If on demand fire safety you need protection of wooden structures from fire, you can use complex fire and bioprotective preparations FENAKS, SENEGA-OB.
Figure 9. Destruction of the rafter leg by house mushrooms when the roof is damaged
Mauerlats, which are based on stone walls, must be located above the level of the attic insulation no less than three rows of brickwork. After treatment with antiseptics, it is necessary to lay a roll waterproofing between the masonry and the Mauerlat.
Elements of the truss system, which are subject to mandatory antiseptic, are shown in table 2.
Attic coverings
When arranging attics, the insulated coating must be partially or completely combined with the roof. The basis of the durability of the combined coating will be the creation of an integral contour of insulation around the perimeter attic floor, as well as providing good vapor and waterproofing around the insulation circuit, its ventilation.
It must be said that the insulation of the combined attic flooring is considered a more difficult task than the insulation wall covering. On the enclosing surface of the attic room, the condensation of water vapor, which is contained in warm air, is higher than in those rooms that are located on other floors of the building. Under normal conditions (air temperature of about twenty degrees Celsius and relative humidity 65%), the water vapor content is about 11.4 g/m3. the dew point will come at 13.2 degrees. Under the attic ceiling, the temperature will be a couple of degrees higher than inside the room, so condensation will begin already on those surfaces that have a temperature of 15-16 degrees.
As a rule, the insulation in the coating attic rooms laid between the rafters. To produce insulation, glass and mineral wool plates of sufficient density are used. In this case, all elements of the truss system are located out of sight. And some of them, for example, rafter legs are partially or completely in the insulation layer. It is worth saying that this scheme makes it possible to rationally use the entire thickness of the coating, but it justifies itself, provided that the work is done correctly.
A large number of problems with the installation of insulation between the rafters arise due to loose contact between the thermal insulation and the side surfaces of the rafter legs. In the event that the gaps between the rafters and heaters are not sealed, which happens quite often, condensation forms. It appears on the surfaces of the rafter legs, as well as locally - in the area of \u200b\u200bthe rafters and on the ceiling.
If the formation of condensate on wooden surfaces occurs systematically, they may be affected by wood-destroying fungi. Given that these processes are secret, they are detected only when the deformation of the rafters becomes noticeable.
This phenomenon can also be observed with insufficient use of insulation. In this case, in winter, the coating freezes, the wood is systematically moistened, as well as the insulation itself with condensate.
The foregoing makes it clear that the protection of the wooden parts of the combined attic rooms from possible biodegradation is a mandatory measure.
It should be borne in mind that visual control of the state of the truss system in such coatings is impossible; bioprotective treatment of wood is carried out with hard-to-wash antiseptics with a long service life. In this case, it is recommended to use the antiseptic preparation BIODECOR-M.
Logs of external walls and beams (see figure 4)
The main reason for the premature failure of block and log walls is their destruction by wood-destroying fungi. To a large extent, this is facilitated by shrinkage cracks, which become a kind of "gateway" for the penetration of fungal infection and atmospheric water into the layers of wood. They cause internal damage to the timber or log (this is the central rot).
Practice shows that in buildings made of timber and logs, rot most often affects the lower crowns.
What is happening can be explained by the direct impact of atmospheric precipitation on the structures, as well as the consequences of differential condensation, which is observed when installing wooden elements with large sections directly on a brick or concrete base without laying thermal insulation between them.
In spring, when daily fluctuations in outdoor temperature are more significant, during the day a massive plinth warms up more slowly than wood. Due to the temperature hysteresis of the plinth and wood in the mass of wood, condensation of air water vapor will be observed at the point of contact with the plinth. As a result, internal (central) decay of the lower crown may occur. This can be avoided by complex (chemical and structural protection measures). It is worth saying that chemical protection measures are reduced to treatment with a BIODECODER-M preparation that is difficult to wash out, it is applied in a specific way, which is called “wet on wet”. Shrinkage cracks must be filled with special care. It is desirable to use this method for those lower crowns of logs that already have cracks. Otherwise, when using insufficiently dried, cheese logs, after drying, cracks appear there. They will break the protective layer. This can lead to nullification or a significant decrease in the expected antiseptic effect.
To protect the cobbled and log walls of the house from biodegradation, exposure to atmospheric precipitation, they are often sheathed with a decorative board (this can be lining, land-house, block-house, etc.), sheet materials, siding. Brick cladding is also often used. Facing is located at a distance of about 25 centimeters from the wall. This provides a drying mode for the structures. The air gap must be designed in such a way as to completely exclude the ingress of precipitation into it. Ventilation occurs with the help of air entering under the casing from below and exiting near the eaves. In cobbled and log walls with brick cladding, the ventilated gap should be at least 5-7 centimeters.
The practice of construction, as well as the operation of buildings with sheathing of the outer walls of the house decorative board indicates that when laying the cladding, wall beams and logs are in conditions where the possibility of the appearance of wood-destroying and mold fungi is either completely absent or minimal. When facing walls with bricks, the ventilation gap is often blocked by mortar, which falls down during the device brickwork. Because of this, an unventilated space is obtained between the cladding and the wall. In this case, the likelihood of mushrooms appearing on the surface increases significantly. That is why, for prevention, it is necessary to perform an antiseptic treatment of the outer surfaces of wall beams and logs before facing with bricks. For this, preparations such as BIODECOR-M, KRAM-S or KRAM can be used (see table 2)
Exterior plank sheathing of gables and walls
It must be said that it is necessary to protect the plank sheathing itself, both from the inside and from the outside. In many ways, the durability of the sheathing depends on the profile of the board, its placement on the facade of the building, and the type of attachment to the frame. Sheathing boards are either horizontal or vertical. Each of these methods has its own advantages and disadvantages.
If the boards are arranged vertically, atmospheric water can flow freely along the fibers and linger only at the bottom. If the height of the plinth is insufficient, the sheathing boards are subjected to increased moisture from slanting rain, melting snow and splashes from the blind area. The same can happen in the absence of low tides or with protruding plinths. At the same time, the ends of the boards are waterlogged, which creates optimal conditions for biodegradation of wood. If decay occurs, all boards will have to be replaced.
The variant of the sheathing device with the placement of the boards horizontally also has its drawbacks. Experience suggests that in the case of a horizontal arrangement of boards, rainwater will drain much worse than those boards that are located vertically. This is due to the fact that during operation the surface of the boards becomes fleecy (rough) over time, small cracks may appear on it. This promotes the penetration of moisture into the wood. On horizontal boards, unlike vertical boards, mold or staining mushrooms often appear. They are mainly localized at the bottom of the boards, where there is more moisture.
Sheathing boards must be processed in order to exclude biodamage, give the surface of the boards a decorative effect, and reduce board warpage during operation. At the same time, the outer surface of the boards is often covered with opaque or glazing coatings. After using such coatings, it is necessary to treat the surfaces of the boards with a tinted or colorless primer antiseptic. It could be SKOLTEKS-PR. The drug is effective against blue stain, wood-destroying and mold fungi, insects (Figure 10). SKOLTEX-PR has a high penetrating ability, so it can create a stable protective layer on its surface, without forming a specific "film", without interfering with gas exchange. In addition, SKOLTEX-PR does not hide the texture of the material and increases the adhesion of protective, decorative and paintwork materials to wood.
Figure 10. Pine board after a year in a humid chamber:
On the right - the area that was not treated with a protective preparation, on the left - the area of the board that was treated with SKOLTEX-PR.
The reverse side of the cladding board should also be treated with the SKOLTEX-PR bioprotective agent for prevention purposes. Also for these purposes, preparations KRAM-S, DOMOVOY can be used. These compounds stain the materials, and therefore, if the drug accidentally gets on the front surface, they do not leave any traces.
load-bearing elements wall panels And frame walls referred to as hidden constructive elements. The state of the wood can only be known by indirect evidence(for example, by the deformation of the walls), since they are not subject to visual control. The main reasons for the appearance of wood rot in these walls is the regular condensation of moisture when the walls freeze due to insufficient thickness of the insulation or its precipitation.
Figure 11. Plinth and exterior wall made of timber-framed panels:
1 - elements of the supporting frame of the floor panel; 2 - bottom sewing (plywood, boards, etc.); 3 - insulation; 4 - floor boards; 5 - vapor barrier; 6 - bearing vertical edge of the wall; 7- inner lining; 8 - boards of outer skin; 9 - bars for fixing the skin; 10 - supporting edge of the wall; 11 - wooden rand beam; 12 - pile, columnar foundation; 13 - tarred tow; 14 - waterproofing; 15 - plinth sheathing; 16 - ventilation air; 17 - blind area
If you follow the rules of structural anti-rot prevention, wooden frame walls and panels, special measures chemical protection from biodegradation will not be required. It should be taken into account that it is impossible to guarantee the absence of conditions for the formation of fungi inside the walls and on wood. That is why the antiseptic treatment of the frame of the walls, as well as the panels, does not hurt (see table 2). bars bottom strapping walls, as well as the supporting ribs of panels and rand beams, must be treated with a hard-to-wash antiseptic preparation BIODECOR or BIODECOR-M. To perform bioprotective treatment of others structural elements panel and frame walls, antiseptic compositions KRAM, KRAM-S, DOMOVOI can be used. The main condition for bioprotective treatment with these antiseptic preparations at the construction site is the protection of the impregnated wood from the effects of precipitation.
Partitions. Protective treatment antiseptics are needed only for wooden elements of interior partitions that are adjacent to concrete or brick exterior walls in a strip of half a meter. In the partitions of bathrooms, racks, strapping, braces are subject to antiseptic. The compositions used for their bioprotective treatment are shown in Table 2.
Terraces, porches, balconies. During operation, balconies and terraces, depending on the design and architectural solution to varying degrees are exposed to natural influences, including atmospheric precipitation. They lead to the systematic moistening of wood, which can cause wood-destroying fungi. Most often there is a bi-destruction of fences and decking open terraces, balconies (Figures 12 and 13).
They can be protected with the help of complex protection, including wood impregnation with a hard-to-wash composition, followed by the application of a protective and decorative coating. Antiseptic treatment of wood can be carried out using BIODECOR, BIODECOR-M preparations. To protect the surface from moisture, use paint and varnish compositions on organic/ water based, protective and decorative preparations, their choice on the modern market is quite wide.
Figure 12. Destruction of a balcony fence by a house fungus, which does not have chemical and structural protection
Figure 13. The defeat of the house fungus flooring balcony (this is a view from below)
Long-term and reliable protection of porch elements from rot, as well as loggias, balconies, is provided with BIODECOR and BIODECOR-M antiseptics. Given that the most vulnerable to decay are the lower ends of the pillars (chairs) 5 and the bed 1, which are in contact with the ground (Figures 14 and 15), they must be impregnated with an antiseptic composition to a sufficient depth. This is the most affordable and easiest way to process wood in a construction environment. Thus, it is possible to obtain high-quality impregnation - by soaking wooden elements in an antiseptic solution for several days. To make the soak, you can use a variety of containers. These can be bathtubs that are made of boards and lined with several layers from the inside. polyethylene film. To impregnate the lower ends of chairs that are installed in the ground, it will be useful plastic barrels(Figure 16). Other elements of the porch (girders, flooring, steps, stringers) are treated with an antiseptic. To do this, the composition is applied to the surface by spraying, brushing, or short-term immersion in an antiseptic composition.
Figure 14. Porch:
1 - bed; 2 - kosour; 3 - steps; 4 - flooring; 5 - chairs; 6 - run
Figure 15. Installing a wooden post in the ground:
1 - pillar; 2 - the end of the column, impregnated with an antiseptic composition; 3 - roll waterproofing; 4 - knitting wire
Figure 16. Impregnation of pillars that are installed in the ground:
1 - pillars; 2 - barrel; 3 - the level of the composition for processing; 4 - base
A list of structural elements that are subject to biodegradation and must be antiseptic.
table 2| Houses from a bar (log), frame and panel type | |||
| Constructions | Elements to be antiseptic | antiseptic | |
| Rafter system (Fig. 8) |
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| Exterior walls | From round wood and timber (Fig. 4) |
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| Frame and panel walls (Fig. 11) |
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| Overlappings | Socle beam structure (Fig. 4) |
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| Basement panel (Fig. 11) |
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| Interfloor and attic (Fig. 1) |
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| Partitions |
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| Floors (fig. 4 and 11) |
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| Window and door frames (Fig. 8) |
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| Terraces, balconies, porches (Fig. 14) |
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Technical director: A. D. Lomakin
The roof truss system is a wood material that is easily destroyed on contact with moisture and quickly ignites in the event of a fire. How to process the rafters in order to extend their service life and exclude the formation of mold microflora. Which of the formulations on the market is the most effective? This depends on the type of wood and the prevailing climatic conditions. Humid - need protection from water, hot - you need to protect the tree from fire.
What should be the composition
Any tool that you decide to use to cover the truss system must meet the following requirements:
- penetrate deeply into the structure of wood fibers;
- do not contain copper sulfate, potassium bichromate, arsenic, chromium;
- dissolve well in water, but do not wash off the tree;
- effectively protect floor beams and lathing from mold, rot, fungus, and prevent ignition.
After that, it is worth deciding what is more threatening to the rafter system - rot or fire. For humid climatic conditions, an antiseptic is chosen that will penetrate deep into the tree, and then additionally coated with a fire retardant. The fact is that you can impregnate wood only once. The strengthening of the properties of wood to resist the formation of rot or fire depends on which composition is applied first.
What are antiseptics
Antiseptics for floor beams and battens may have an additional decorative effect. The composition of the funds includes alkyd resin, which gives the tree specific color. For the rafter system, water-soluble antiseptics are most often used. They have a number of advantages:
- penetrate deep into the wood structure;
- they are easy to apply to the elements of the truss system;
- dry quickly and allow the tree to breathe;
- form a moisture protective film on the surface of the tree.
High-quality antiseptics should have antimicrobial (biocidal) and antifungal (fungicidal) properties, as well as provide reliable protection against insects - insecticidal properties.
Water-soluble substances mainly contain sodium fluoride and silicofluoride, a mixture of borax and boric acid, pentachlorophenol, a mixture of zinc chloride with sodium (potassium) chromium peak. The compounds are toxic only to microorganisms and are completely harmless to humans. There are also products that are soluble in oil, petroleum products and light solvents.
Methods for applying antiseptics
Impregnation (surface impregnation with an antiseptic) is performed by completely immersing wooden elements in the composition or by applying the substance with a spray gun / ordinary brush. For immersion, a special bath, trough or even a ditch is used, after lining the container with plastic wrap.
The immersion time of the material depends on the specific antiseptic. Typically, the manufacturer indicates on the packaging 30-60 minutes for small and medium-sized wood. When immersing large trusses, for example, for a roof made of natural tiles, the impregnation time is increased to four hours. After drying during the day, all the ends of wooden structures are processed.
When treated with an antiseptic manually by spraying, sprinkling or staining, the effectiveness of the penetration of the composition deep into the wood is markedly reduced. Although this method requires a small amount of antiseptic composition.
The coating is carried out in several layers with an application interval of about half an hour.
The most popular antiseptics
Well proven in practice modern facility Senezh. Such an antiseptic can be used to treat the roof, wooden crate, floor beams. The composition is presented as a ready-to-use water-based solution. Its advantages: 
- biosecurity for a period of 30-35 years;
- type of composition - difficult to wash out;
- chemical bonding with wood;
- penetrates deeply into the fiber structure without increasing hygroscopicity;
- allows the tree to breathe;
- has a decorative effect.
The recommended consumption is 250-300 g/m. cube when applied without immersion, 60-80 kg/m. cube when soaking. Senezh penetrates deeply into floor beams and other elements, forming a two-level protective barrier. Interferes with development of fungi and mold microorganisms, insects. The manufacturer produces various series of antiseptics - Ultra, Bio, Thor, Sauna for specific wooden structures.
Estonian-made Pinotex Impra is distinguished by its high efficiency. Suitable for bioprotection of floor beams, lathing, mauerlats, rafters. It is a water-based antiseptic with an alkyd binder. Deeply absorbed into the surface of the wood, provides good protection from rot, blue, mold.
The consumption of the substance is from 85 to 200 g per square meter depending on the wood processing - sawn or planed. Pinotex Impra cannot be used for elements of the truss system already affected by microorganisms, in contrast to the composition of Senezh.
Means of production in Russia Drevotex is used to protect wood material from the formation of rot, mold. Main characteristics:
- effectively protects floor beams, boards from atmospheric moisture;
- the bio series is suitable for the prevention of healthy wood material, the anti-mold series is used for the wood affected by focal microorganisms;
- type of impregnation - difficult to wash out, allows the tree to "breathe";
- the term of bioprotection of the truss system with the integrated tool Drevotex is about 30 years;
- the expense of means makes 250-350 g/sq.m. m when brushed and 200 kg/m. cube when immersed.
The product can be applied to new wood or as a treatment for an existing roof structure.
When choosing antiseptic compounds for floor beams, sheathing boards and mauerlats, it is necessary to pay attention to the moisture content of the wood, since not all antiseptics are suitable for wood with a moisture content of more than 20 percent.
The use of fire retardants
Fire protection is designed to give wood material additional qualities - fire resistance, flammability reduction. If you decide that the likelihood of a fire is higher than the possibility of rotting roof structure, first of all, all wooden fragments of the roof should be treated with flame retardants.
They are classified into the first and second efficiency groups. Means of the first group create fire protection for 5-7 years, so they are more effective. Predominantly, the basis of fire retardants include ammonium phosphates and sulfates, borax, boric acid and combinations of these substances.
All flame retardants are divided into:
- Impregnations are solutions of salts that are applied manually or immersion.
- Coating flame retardants - have a pasty consistency.
- Lacquers are used for decorative purposes. On the roof, their use is redundant.
- Paints form a thin protective film on the surface.
Most often, to protect floor beams and rafters, impregnation is used when the flame retardant will act as the main protection, and coating if the flame retardant is applied to the antiseptic. Methods of coating with fire protection are identical to the application of antiseptics. There is a large selection of compositions of the first and second categories on the market. Neomid is very popular.
Since the composition has received a lot of positive customer reviews, you can take a closer look at its properties.
Neomid 530 - fire protection
The tool is suitable for any type of wood surface - sawn or planed floor beams, boards, rafters, battens. Main advantages:
- fire protection for a period of ten years;
- has antiseptic properties;
- does not contain toxic substances and formaldehyde;
- does not interfere with further processing of the tree;
- does not change the hygroscopicity of the material;
- supplied ready to use;
- made on a water basis;
- in terms of danger to humans, it occupies the same category as household chemicals, - not dangerous.
Neomid formulations are available in different series. Some products are designed to protect floor beams and other elements of the truss system from insects, rotting, blue, and are used as wood bleaches. Neomid 530 is an effective fire protection that is currently the most popular.
Before processing the rafters, you need to correctly select the priority of protection. The composition that is applied first will be the main one. The second substance will perform an additional protective function.
Wooden floors between floors are suitable for almost all types of buildings. They are compatible with wood, brick and concrete buildings. Structures are mounted not only between floors, but also in attic and basements. In these rooms you can’t do without them, but the arrangement of wooden floors between floors differs from basement structures.
Features of wooden floors
The flooring device includes, for the most part, only wooden elements. However, absolutely any materials are used to finish the ceiling and floor. The main thing is to correctly install the structure itself.
One of the most important functions of the floor is soundproofing. It is very easy to attach any insulating materials, including slabs. On top, you can easily mount any modern finish.
Very important advantage wooden structures - light weight. Wooden floor elements do not exert significant pressure on the base of the building. Therefore, they are often used in houses with a light foundation.
Installation, carried out according to the rules, contributes to the natural air exchange of the room. At the same time, the heat and sound insulation of the rooms is not disturbed.
In general, wooden structures are very durable. They allow you to create light and durable floors in a short time.
Technical requirements for floors
Interfloor structures consist of the following elements:
- beams;
- bars;
- board layer;
- heat and sound insulating layer;
- waterproofing film;
- finishing board;
- ventilation slot;
- plinth.
Note! Wood belongs to the class of flammable materials. In addition, it is prone to putrefaction, fungi and various bacteria. Therefore, floor materials must be processed before installation. The minimum set of impregnations consists of flame retardants and antiseptics.
Installation and processing
To do right wooden floor between floors with your own hands you need to deal with the device of its design. It consists of a beam frame and sheathing made of board or sheet chip materials.
The role of the heat-insulating and sound-proofing layer is performed by the rolled material. Most often, glass wool, mineral wool or similar insulators are used for this. Sometimes expanded clay or polystyrene is used. However, the first makes the structure very heavy, and the second is highly flammable.
For wooden floors between floors in saunas and baths, it is very important to properly arrange waterproofing. In this case, vapor-tight films that allow moisture to pass in only one direction are optimal. The material consists of expanding cones that absorb moisture only from the porous side. No moisture is released from the reverse side of the cover.
Important! Vapor-proof coatings are laid with the porous side to the insulation, "face" to the room. And for the room above, the film is mounted vice versa.
floor beams
To figure out how to make a wooden floor between floors, you need to know the features of the structure frame. Its basis is wooden bars. Most often, elements of 15-25 cm in height and 5-15 in thickness are used. A distance of up to 1 m is made between the beams, depending on the section of the elements.
Note! The greater the load on the floor, the greater the cross section of the beams should be.
The supporting ends are made from 150 mm in length, they are laid in a "beacon" way. First, the installation of the extreme beams is carried out, and intermediate ones are laid between them. Evenness of laying is checked with a level. The middle beams are laid according to the template. For leveling, you can use various resin linings from scraps.
Important! It is impossible to use hewn, pointed chips to level the beams.
The bars are laid with the same step around the entire perimeter, strictly parallel. Before laying, they are treated with antiseptic impregnations and wrapped in 2-3 layers with roofing material. For brick and block buildings, floor beams are coated with bitumen from the ends. This technique protects the wood from moisture. For walls with a thickness of 2.5 bricks, air vents are left for ventilation. And at the junction of wood with walls, roofing material is laid under the beams.
Installation of rolling
To cover the floor between floors use various materials from wood, including boards, plywood and particle boards.
The bottom flooring acts as a draft floor in the ceiling, it is on it that they lay thermal insulation material. It can also be mounted directly on the beams from below. In this case, it performs the function of a draft ceiling, on which you can immediately mount the finishing material. A floor made using a second-rate board will cost several times less.
The distance from the beams or logs is determined by the thickness of the boards that cover the rough coating. They bear the brunt of the burden. So, if boards of 2 and a half centimeters are used indoors, for attic spaces a step of 50 cm is needed, and for residential - 40 cm. Therefore, it is recommended to use a thick board of 4-5 cm for flooring.
Ways of laying the basement
For wooden structure the base is required cranial bar. It will insulate the floor. After all, it is on it that panels or a board covering the insulation are mounted.
A more popular option is a draft layer of rolling or unedged boards. The material is mounted on wooden block with a square section and a side of 5 or 4 cm. It is best to attach the cranial beam to the logs with self-tapping screws, but you can also use nails.
Advice! You can mount the board not on the cranial bar, but in the groove (quarter). It must be cut with chisels or power tools. It will take longer.
The draft floor of the basement is insulated with bulk materials, including sand. Often use sawdust impregnated with an antiseptic or mineral wool from 10 cm in thickness. To protect wood structures, a waterproofing layer is covered from below. Most practical option- bituminous roll materials. For rooms in contact with moisture, waterproofing is also mounted from above.
Warming and soundproofing
The heat-insulating layer is very important in the floor structure: it performs the function of sound insulation. Therefore, for its arrangement, modern synthetic and mineral heaters. They are not affected by bacteria and fungi, so they have a longer service life.
Mineral wool is very popular. However, for baths and saunas, some rolled materials are contraindicated. In such rooms it is not recommended to use slag wool, as it contains metal suspensions. These particles rust from moisture, and the cotton wool sags, losing its properties.
Most often, in rooms with normal humidity, roofing material is used for waterproofing. Bituminous materials have low cost and excellent performance characteristics. Dense polyethylene is laid on top of the roofing material.
A heat-insulating material is mounted on top of the film. It is very important that there are no gaps between the layers of wool or foam, otherwise there will be low heat and sound insulation in the room. If used plate heaters based on foam - the gaps are sealed with mounting foam.
By mounting the floor of the second and first floors on wooden beams, you can save a lot. Such structures will cost several times cheaper than concrete, in addition, you can handle the installation yourself.
During work, certain rules must be observed. For example, it is necessary to use beams of a certain section, and the step should be adjusted taking into account the floor area.
