How to choose wood for building a house: which species are best to choose.

“Although all the Russians’ weapons consist of only axes, not a single architect will do better than they do... There are no nails or hooks, but everything is so well done that there is nothing to blaspheme,” wrote the French traveler Jean Savage from 400 years ago. Dieppe. Once upon a time in Rus' they not only cut down large houses without a single nail, but also erected multi-bowed temples. For many centuries, wood was the main building material in Rus'. And this is due not only to the fact that the country is rich in it. A huge role in its popularity was and is played by the fact that it is a natural, environmentally friendly material created by nature itself. These days, tired of the hustle and bustle of the city, many are moving to live closer to nature.

Coniferous wood.

Spruce.

Spruce, like pine, is a popular wood for private construction. This is due to its characteristic positive qualities:

• low thermal conductivity due to the friability of wood;
• has a positive effect on human health, especially on the cardiovascular system;
• Spruce wood is capable of maintaining a healthy indoor microclimate.
• durability of lumber from this species;
• the presence of natural antibacterial substances in the wood, thanks to which the spruce is not prone to turning blue;
• Spruce wood, such as pine, is a soft and not very dry species.

The disadvantages of spruce timber include the following features:

• far from the best indicator of strength and wear resistance;
• tendency to the appearance of putrefactive processes;
• a large number of small and large knots, which makes cleaning and leveling the trunk difficult.

If you decide to build a house from spruce timber, you need to know that this wood requires initial processing, and then, during operation, quite frequent periodic treatment with special paints, varnishes and impregnations.

Pine.

If we consider all types of wood as a whole, perhaps the most used material for building houses is pine. Everything is explained by the predominance of this wood and its affordable price.

At the same time, pine lumber that has undergone proper drying has quite decent performance characteristics.

The advantages include the following:

• low dryness - this means that a house made of this wood will not shrink much;
• softness - this quality greatly simplifies wood processing;
• moderate density contributes to low thermal conductivity;
• good resistance to putrefactive processes;
• smoothness of the trunk and a small number of large knots;
• low tendency to form large cracks.

The disadvantages of pine include the following factors:

• the appearance of a blue color, which can lead to destruction of the structure of the material, so it should be treated by treating the wood with special compounds;
• If we compare pine with other types of wood, we can note its lower resistance to rotting and cracking, as well as weaker strength characteristics than, for example, larch, cedar and oak.

When choosing pine for building a house, it is important to obtain reliable information about the conditions and location of its growth. The best quality is considered to be material obtained from trees grown in the northern regions.

Larch.

Larch is ideal for building a house because it has almost ideal natural qualities:

• Larch is absolutely not afraid of moisture, does not rot and has excellent strength.
• high density and strength of wood;
• are not subject to rotting, blue discoloration and the negative effects of various microorganisms and insects;
• durability - houses made of larch can last for several centuries;
• moisture resistance and resistance to various atmospheric phenomena - precipitation, extreme temperatures, infrared influences;
• has a beneficial effect on human health - increases immunity, slows down the aging of the body.

The disadvantages of larch include the following:

• hardness of the structure, which makes processing difficult, but thanks to this property the wood has pronounced strength;
• severe drying of wood;
• the high cost of building materials, exceeding the cost of spruce and pine by two, and sometimes several times.

Cedar.

Cedar is not widely used for building houses, as it has a very high cost. However, its considerable price is due to its noticeably high performance characteristics, which make the design reliable and durable:

A cedar house is very expensive, but it guarantees quality and durability.

The obvious advantages of cedar wood include the following:

• wood dries little;
• complete resistance to rotting processes, damage by insects and various microorganisms;
• resistance to temperature changes, atmospheric and chemical influences;
• There is virtually no risk of cracking;
• resistance to deformation;
• availability in processing;
• the presence of essential oils in wood, which helps create a healthy microclimate in the house, as they are a natural antiseptic and air flavoring agent.

Of the minuses, besides the already mentioned high price, there is nothing more to say.

Deciduous wood.

Aspen.

Aspen is rarely used in house construction. This is due to the fact that the material does not have the properties necessary for housing construction. Most often, aspen is used in the construction of bathtubs or for interior decoration.

Aspen is suitable for a bathhouse or for decoration, but building a residential building from it is far from the best option.

The advantages of aspen lumber include:

• average drying capacity of wood;
• resistance to deformation, abrasion and moisture;
• ease of use.

However, this breed has its significant disadvantages:

• aspen is susceptible to natural diseases, so only trees of a certain age are used for construction;
• the service life of aspen lumber is much shorter than that of other types of wood;
• There are certain requirements for the harvesting and processing of wood that guarantee the preservation of its positive characteristics, but compliance with which is difficult to verify when purchasing.

Birch.

Birch, like aspen, is not suitable for building a house, as it is not durable. In addition, there are other obvious disadvantages:

• the wood is a very dry, hard species - this feature makes processing difficult;
• Birch absorbs moisture well, so it is prone to very rapid biological degradation if a set of protective measures is not applied.

Birch is also difficult to classify as the optimal material for building a house.

However, this wood has its advantages - it is strength and resistance to impact loads, a beautiful textured pattern and a delicate light color.

However, if for some reason it was decided to build a house from birch logs, experts recommend laying out the first two lower rows of walls from a more moisture-resistant material, for example, oak or larch.

Alder.

Alder is quite actively used in the construction of house walls, because, unlike some types of wood, it has the following positive qualities:

• the low density of the structure significantly reduces its thermal conductivity.
• Having a low weight, you can equip any foundation for walls.
• high moisture resistance corresponding to this parameter of oak and larch;
• homogeneity of structure;
• alder does not warp or crack;
• wood has a large number of pleasant colors.

Alder gives the cut a characteristic shade. And the material itself for building a house is very good.

Among the disadvantages of this material are:

• the fragility of wood - therefore, driving nails into it can cause it to split;
• with constant contact with the soil, alder can be affected by rotting processes, although in the manufacture of water containers it works without problems for a very long time;
• insufficient fragility and elasticity of wood;
• The material for building a house requires special protective antiseptic treatment.

Oak.

Oak has unique qualities, so it can be used in the construction of any covering and supporting structures.

Oak is suitable for any construction and finishing work. The only doubt is about the cost-effectiveness of this approach, since the cost of this wood is very high.

The advantages of oak wood include:

• medium dryness, thanks to which the wood dries evenly;
• resistance to damage by insects and microorganisms;
• high strength and reliability;
• very beautiful textured pattern and valuable wood tones.

It can only be noted that oak wood is practically devoid of disadvantages, except for its very high cost. But it is precisely this “minus” that in most cases makes it unprofitable to use this material for building a house.

Main performance characteristics of wood used in construction:

Wood species such as poplar, linden and maple should not be considered as materials for building a house, as they are short-lived and unstable to humidity and other negative external influences. Although there are offers on the market of ready-made wooden cabins made from wood of these species.

Hardness indicators

This parameter shows how resistant the wood is to mechanical damage and can be processed. There are currently three hardness categories:

• Very hard (hornbeam, acacia, rowan)

• Hard (oak, larch, maple, ash, beech).

• Soft (fir, poplar, pine, spruce, aspen, linden).

There is one interesting fact: if a tree grows quickly, then its wood is soft. But in species that grow slowly, the wood structure is solid.

Areas of application of different types of wood.

According to their purpose, all wooden building materials are divided into finishing and general construction materials. The latter are intended for enclosing and overlapping structures, as well as other loaded building elements. Finishing materials are used to decorate the surface.

From the information presented above about tree species, it is clearly seen that they differ in their technical and operational characteristics. Therefore, almost always, when building a house, several types of wood are used, each of which is best suited for a specific construction site.

• Pine is excellent for the construction of enclosing structures.
• Spruce beams are often used to make floor beams, elements of the rafter system, flooring, and ceiling cladding. The unique properties of larch even make it possible to strengthen the banks of tanks and install walkways and pillars.
• Larch is used for laying the lower edges of the house, as it has high moisture resistance. In addition, larch trunks are used for pile foundations, even for structures built above water, such as bridges or supports, as well as for strengthening the banks of reservoirs.
• Oak is most often used for windows, doors and openings. In addition, oak can be used for both interior walls and floors.
• Maple, basswood and alder are used for carpentry and carpentry due to their flexible structure. For example, this wood is used to make trays or carved cornices.
• Birch or alder is used for interior decoration. The textured pattern and color shades of alder wood allow it to be used to imitate more valuable types of wood.

Wood and foundation

(don’t bury your money in the ground, you will need it later)

In low-rise buildings, heaving forces usually exceed the load acting on the foundations, as a result of which the latter are subject to heaving, i.e. deformed. As a result, this brings the walls of the building into disrepair. Therefore, when constructing low-rise buildings, it is more reasonable to use shallow, shallow or non-buried foundations.

As a result:

• the cost is reduced due to a reduction in labor intensity, concrete consumption and the timing of zero-cycle work;
• almost complete use of the bearing capacity of soils and foundation materials;
• the volume of formwork, reinforcement and earthworks is reduced;
• it is possible to build foundations with the same efficiency in different weather and soil conditions.

If necessary, to increase the load-bearing capacity, it is advisable to provide a sand-crushed stone cushion.

Wood materials used in the construction of a house.

When building houses, various wood products are used for the construction of enclosing structures and their cladding - these can be solid logs or lumber made from them - boards, beams, slats, etc.

To have an idea of ​​what wood materials are on the market and in what area of ​​construction they are used, their main varieties will be discussed below:

Construction of a log house from handmade logs.

Mechanical or handmade logs are a building material for the construction of enclosing load-bearing structures. Logs treated with these methods are more durable in structures not protected by a facade than their rounded counterparts, since the natural protective layer located directly under the tree bark is not removed from them. But working with such logs is more difficult, since their “geometry” can “dance” a little in one direction or another.

Structure made of rounded logs

The rounded log has an ideal geometry, which is achieved thanks to special processing. During the rolling process, several top layers are removed from the product, which reduces the protective properties of the building material. Therefore, such products require mandatory impregnation with antiseptic primer solutions. This material has a more aesthetic appearance and is more expensive than conventional logs.

Calibrated logs

Calibrated logs - the entire batch of material has the same diameter. Unlike the products described above, calibrated logs have exactly the same diameter. To build a log house for permanent residence, the calibrated log must have a diameter of at least 250 mm, otherwise the structure will have to be additionally insulated. Most often, after rolling such logs at the factory, a longitudinal intercrown groove is immediately selected (as shown in the illustration above). Solid Logs - These lumbers, usually cut from the core of a log, can be rectangular or square in a variety of sizes.

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Massive timber

Solid wood can be divided into three subtypes - these are products of natural moisture with a regular and profiled cross-section, as well as profiled ones that have been dried in special chambers.

Untreated wood with natural moisture has flat surfaces, and profiled products have longitudinal grooves to facilitate their joining when building walls.

It is impossible to immediately build a house from this material, since it requires time for atmospheric drying, during which the wood may crack and warp.

From timber without a profile, you can build the walls of a paved structure or for the frame of a frame house. It is also used in the construction of a rafter system, for example, a mauerlat, beds, racks, etc.

Dried profiled timber is the best option for building walls, but it has a higher cost.

The minimum cross-sectional size of wood intended for walls must be at least 150 ÷ ​​200 mm. Otherwise, additional thermal insulation will be required to ensure comfortable living in the house.

Glued laminated timber

Glued laminated timber is a prefabricated structure consisting of 3 ÷ 5 panels glued together under pressure. The product is then processed and profiled.

These products do not deform or crack to their full depth, since the board is dried in a special chamber before gluing, in which the optimal moisture content of the wood is achieved.

In addition, laminated timber, unlike solid wood, can have a very large cross-section, which makes it possible to build walls that do not require additional thermal insulation. But, however, the cost of glued profiled timber may seem terribly high.

Carriage

Carriage is lumber that is a cross between a block and a log. It is made by cutting out two sides of a large log. So, the cart can be called a log with two flat side surfaces.

The carriage can also be purchased without drying or already fully prepared for construction. Of course, material that has undergone special drying will cost much more.

Board

A board is lumber that can have a standard length corresponding to a log (usually 6 meters), a thickness of up to 100 mm and a width of twice or more thickness.

Boards are used in the construction of a house at all stages and in a variety of areas.

This is a rafter system, floor beams, logs, cladding of frames, floors, ceilings, production of lining for decorative external and internal decoration. Boards are also often used as support material.

The board can be dried and processed like logs and timber, or it can have natural moisture. Undried boards can only be used for preparatory work, for example, when constructing formwork for the foundation.

Wooden floors

Interfloor ceilings consist of rolling beams that form the ceiling, floor and ballast backfill. At the bottom of the beams, to support the run-up, cranial blocks are nailed or tongues are selected. The roll is covered half the height of the beam with a layer of clay-sand lubricant or fine slag and covered with roofing felt or film. Then they cover it with a plank floor, and if beams are rarely laid, the logs are pre-stuffed to avoid instability. Attic floors must be carefully insulated through roll gaskets, mainly with materials or mixtures that do not rot due to leaks or condensation moisture and easy fire. For this, we can recommend mineral wool, foam glass blocks, etc. Fill around pipes only with non-combustible materials.

The permissible sections of beams and beams made of logs, depending on the span, are taken according to the table compiled by the famous specialist and practitioner A.M. Shepelev.

It must be said that wooden beams, moreover, log beams (not edged) in which the working cross-sectional area during bending is used to the maximum, have continued to be very widely used since the 18th - 19th centuries in domestic multi-story (8 floors and above) construction - right up to the beginning of the 40s ., last century. And this had a great reason: fairly affordable wooden beams, 3 times superior in fire resistance to steel ones - with the same load-bearing capacity, but which were then in great short supply. Nowadays, this fact is being discovered all the time during the massive reconstruction of a multi-story historical building. (Reference book DD 2002 p. 137)

Features of choosing a tree.

General recommendations for choosing materials.

Wood grown in northern climates is considered the highest quality material for building a house. This is due to the fact that initially it has low humidity due to the natural characteristics of the regions where summers are short and quite cold. In this regard, the increase in the diameter of the wood occurs more slowly, creating a high density of the structure, due to which the material acquires excellent strength, moisture resistance and durability.

If you look at a cut of a tree grown in such conditions, you will find that it has a large number of tightly compressed annual rings. When purchasing a piece of wood, a carriage or a board, the annual rings and their position are clearly visible at the end of the product.

When inspecting lumber, it is necessary to keep in mind that there are several types of lumber, the most important of which are transverse, radial (cut along the log through the core) and tangential (cut along the edge of the log, along the grain or at one angle to the core).

With a tangential cut, the greater the angle of inclination of the cut relative to the core, the greater the distance between the growth rings. This type of cut is often made for blanks for decorative elements, when it is necessary to emphasize the beauty of the textured wood pattern.

An important criterion when choosing a wooden building material is its humidity, which should not exceed 22% for both the selected lumber and the first, second and even third grade.

This optimal residual moisture parameter is achieved through artificial drying or long-term storage of the material in a well-ventilated place and appropriate storage.

Products made from recently sawn wood can be unpredictable - when drying, they can begin to warp, change linear dimensions and crack. Therefore, they cannot be used for construction without achieving the required humidity level.

The moisture content of the lumber used to build a house should not exceed 22%. Of course it's better and lower.

After studying this table, you can see how much the density of wood decreases as it dries, and you can also imagine how the walls of the building shrink.

If you plan to build a house from chopped logs or a rod of natural moisture, then you should immediately remember that the house will be ready for living only at the end of the second season after installing the log house, since it must stand and shrink. If you hastily install windows and doors, as well as install ceilings and lay floors, without waiting for the walls to shrink, gaps will appear between the floorboards, as well as between the walls and window and door frames. Accordingly, many work steps will have to be repeated.

Provided that there is no possibility or desire to delay construction and wait for the walls to shrink, then it is necessary to purchase seasoned and treated wood or laminated veneer lumber with a moisture content of 12 ÷ 15%. Lumber that has undergone special drying or, like laminated veneer lumber, also heat-treated, is minimally hygroscopic, which expands the possibilities of their use and also increases their service life.

When purchasing lumber for construction, you need to pay attention to the grade, residual moisture and appearance of the products.

Humidity is usually determined using a special device - a moisture meter. If the materials were purchased from a bona fide seller, he himself will offer to check the quality of the wood.

Conscientious wood sellers will be sure to demonstrate to the buyer the degree of residual moisture in the lumber they offer.

In the same case, if the seller did not provide such an opportunity, then you can try to evaluate the lumber by sound. When you tap on wood, dry products sound loud, and products with high humidity sound dull.

Another nuance that professional builders advise you to pay attention to is the time of year when the forest was cut down.

The best characteristics are always those obtained from trees cut down in winter.

The best option for building a house is timber harvested in winter. There are a number of reasons for this:

• In winter, the forest is always drier, since there is practically no sap flow in the canals of tree trunks.
• After the trees are cut down, their trunks are placed on frozen ground covered with snow. Thus, they remain clean, and soil moisture is not able to saturate the wood structure.
• By the way, it is better to build a log house in winter, because during this period the air humidity is low and rain is unlikely.

Purpose and application

The purpose of lumber and the possibility of their use are determined by the grade, type of processing and dimensional parameters established by the requirements. As a standard, the following distribution is possible:

• Logs, rounded logs, profiled and laminated timber – low-rise construction, production of architectural forms, landscape design, technical and commercial buildings;
• Beam, beam, board - construction and assembly of load-bearing frames, creation of strength and rigidity connections, rafter systems, other structures and parts;
• Lath, planks - preparation for finishing work;
• Bars, laths and boards with mechanical processing – external and internal finishing works;
• OSB, plywood and other recycled materials – rough and fine finishing;
• Beam, board, slab - construction of technical structures, rough work, budget fencing structures;
• MDF, furniture panels and edged sanded lumber – fine finishing, decorative production!

Defects and quality of wood.

According to GOST, lumber is divided into grades, which depend on the quality of the lumber. So, the wood is divided into four, and the board into five classes.

For the construction and finishing of the main surfaces during the construction of a house, only the selected material or the first grade of lumber is suitable. Other lumber options can be used as auxiliary ones, since they have many disadvantages that are unacceptable for capital buildings.

So, when buying lumber, pay attention to the following disadvantages:

• Putrid spots appear as reddish and dark areas. The structure of rotten wood is fragile and loose.
• Fungal infections. If this defect occurs in wood, bluish or gray-black blurry spots of different sizes appear on its surface. The fungus itself does not weaken the strength of the wood structure, but creates favorable conditions for the development of humus. Small areas infected with fungus are treated with antiseptic impregnations.
• Sapwood or bark are young, actively growing layers of a tree trunk, characterized by high humidity, low endurance and low resistance to damage by parasitic microflora and insects. The presence of this layer on structural wood is considered a defect.
• Knomelos are a pronounced increase in diameter that forms in the lower part of the trunk, which differs in greater hardness and structure from the main wood.
• Wane is the remaining part of the bark along the edges of a wood product, which makes its geometry imperfect and can lead to contamination of the material by fungi and flat wood insects.
• Sprouts form in wood due to mechanical damage, due to which the bark grows in the structure of the trunk.
• Cracks can occur due to adverse natural influences or during drying of lumber, which leads to rupture of wood fibers.
• Wormholes - damage to a tree by a beetle. This defect significantly reduces the strength of the building material.

Now, having determined what defects may be present on wood classified as inferior, you should find out how products of the highest and first quality differ from it.

Premium or selected . These products include wood from selected raw materials. They may contain:

- a minimum number of small healthy nodes located in different areas of the product;

- end cracks of varying depths, but not more than 10% deep and 16% shallow.

The presence of wrinkled and rotten knots and fungal manifestations is unacceptable. The deformation and unevenness of the edges is set within 1 ÷ 2%. The core of the trunk is completely excluded as the weakest point of the wood.

First grade . This category includes lumber of regular geometric shapes. Unlike selected products, in first class the following is allowed:

— healthier knots by about 10%;

- fungal stains and mold, the total area of ​​which should not exceed 10% of the total area of ​​the product;

— sawing defects on surfaces and edges, not exceeding 1/6 of the total length of the product;

The presence of putrefactive manifestations that destroy the structure of the wood is not allowed.

Boards of this class are used in all areas of construction and finishing work.

Second class. The following defects are allowed for wood in this category:

- greater tendency of fibers when sawing;

— presence of resin pockets in softwood lumber;

- blue and gray-black color caused by fungi;

— significant reduction (cutting error).

This type of wood is used for preparatory work - for example, when assembling formwork, when constructing temporary scaffolding. This slab is also suitable for turning under roofs.

Third grade wood is used for attachments and temporary buildings, as well as for the manufacture of containers. The following defects are allowed in related products:

— significant tilt (annual rings on one side of the log are significantly thickened);

- resin bags - up to 4 pieces per meter of shoulder straps;

- wormholes in any part of the product;

— any number of sound nodes of any size;

- cracks in the tank, etc.

The fourth class , like the previous one, is used only for preparatory and auxiliary work. This wood can have many different defects, including wormholes, rot (10%), bluish tint, severe and dull fading, warping and winging.

So, to summarize, it is worth briefly highlighting the main parameters that you should pay attention to when purchasing timber for building a house:

The wood must have clear geometric shapes and a minimum number of the above defects. The annual rings should fit tightly to each other - this indicates the quality of the wood. Wood moisture content should not exceed 20 ÷ 22%. It is not recommended to buy wet lumber, since it is very difficult and often impossible to dry it properly without causing deformation. However, if for some reason such a decision is made, then it is better to lay the damp wood under a canopy or in a well-ventilated area.

In this case, each row in the stack is stacked from the adjacent one in columns of the same section. And exactly in a row, the boards (wood) should not touch each other. It is recommended to purchase lumber from a reliable supplier who, at the buyer’s request, can provide documentation for a specific batch of wood and demonstrate the quality of sorting.

Sapwood and heartwood

The structure of the tree consists of core and sapwood. In this case, the core is dead wood inside the trunk, and around it is a living cell layer called sapwood. In accordance with the ratio of sapwood and core, the following species are distinguished:

• Sapwood (the core of the trunk does not die: linden, maple, birch).
• Sound (the core has a dark shade: oak, ash, pine).
• Mature wood (sapwood and heartwood are absolutely identical in color: spruce, aspen).