Log houses and what is often asked before starting construction

The article is devoted to detailed answers to frequently asked questions about how much a log house can cost, and what factors affect its price. Briefly touched upon are recommendations for choosing a foundation, comparative diagrams of wall thickness and its thermal conductivity coefficient, the choice of a method for laying logs and protecting wood, and warranty conditions. We also offer an article-review about architectural wooden house styles different countries and technological innovations in production, which open up unique opportunities in the design and construction of modern wooden houses using support-beam systems.

The final cost of a wooden house, first of all, depends on the thickness of the log and the type of its processing: manual or mechanical.

Question 1. Is a wooden wall thickness of 180-240mm sufficient for year-round living?

This table shows the thermal conductivity coefficients of various building materials according to СНИП-s:

This graph clearly shows which wall material retains heat most effectively with the smallest thickness.

The numbers at the bottom match the material numbers in the table. On the 7th position are foam concretes, which, when the required density is reached, do not have any advantages in comparison with wood, but are a rather fragile wall material. Pine or spruce goes to the 8th position. Warmer than wood with sufficient density is only sip-panel (9), which, in our opinion, is not an environmentally friendly material.

But back to the table.

We will compare only natural materials. With the smallest thickness, the thermal insulation of wooden walls is practically a reference. Even a clay brick with 20% hollowness has a significant increase in wall thickness to achieve similar thermal insulation performance.

For example, with a thermal conductivity coefficient of 0.16-W / (m * K) for European spruce, we use a log thickness of 220 mm. For a brick with a voidness of 20%, this coefficient is 2.7 times higher and amounts to 0.43 W / (m * K), therefore, the wall thickness should be equal to - 594mm or round off 60cm.

In the case of a solid brick, the picture is even clearer, because it has a thermal conductivity coefficient 3.5 times higher and amounts to 0.56 W / (m * K). In this case, to achieve the warmth of a wooden frame made of a log with a diameter of 220 mm, a brick wall 84 cm thick (220 mm * 3.5 = 840 mm) is needed. For a log with a diameter of 24cm, the math is:

24*2.7=64.8cm - wall thickness for hollow brick

24*3.5=84cm - wall thickness for solid clay bricks

This calculation is valid, because the proportions of the ratio of the thermal conductivity coefficient to the wall thickness for both materials are approximately the same even for other values ​​of Rопр.

Now let's compare the densities and weights of the materials that will be taken into account when building the foundation.

Here the principle of comparison is slightly different. Please note that brick is 3-4 times denser than wood, but 8-9 times heavier, and silicate 22 times. This indicator often becomes critical when building from bricks on light sandy soils and you need to resort to driving piles.

Question 2. Which foundation is suitable for log houses

For the construction of a log house, massive heavy foundations are not necessary.

For an average house of 150-200m2 in two floors, a strip foundation 300mm wide or columnar with a step of 2-2.5m and a section of 300x300mm is enough, while the depth of the columns depends on the depth of freezing of the soil and can be different in different regions, most often 1100mm. Often, clients resort to combining foundations in order to save a little: the entire residential wooden part of the building is placed on a strip foundation, and terraces, sheds and extensions are placed on a columnar or monolithic thickness of about 250mm.

Question 3. How much can a log house cost?

The price of a log house of the company "Modern Wooden Houses" depends on the diameter of the log, the technology of the log house, its configuration and is calculated for a two-story house with an area of 150-200m2

Our company offers a price calculation for two construction options in different configurations:

• "Basic design"
• Turnkey

Complete set "Basic design"
	The cost of a log house made of logs in the basic configuration starts from 1600 gr per 1 m2 (Prices per 1 sq.m are indicated at the time of writing) The basic design provides for the construction of: Sten Partition Floor Beam Truss structures Consumable kit
	The cost of a handmade log house in the basic configuration: Sten Partition Floor Beam Truss structures Consumable kit starts from 4500 gr per 1 m2 (Prices per 1 sq.m are indicated at the time of writing)

Kit "Turnkey"
	The cost of a turnkey log house starts from 5000 gr\m2 (Prices per 1 sq. m are indicated at the time of writing) The "Turnkey" package includes the "Basic design" plus: Plastic two-chamber windows laminated to look like wood Doors - wooden (pine) Floors Euro-board finish ceilings Roofing - soft bituminous (lining of overhangs) Sanding, antiseptic and painting
	The cost of a turnkey handmade log house starts from 7000 gr/m2 (Prices per 1 sq. m are indicated at the time of writing) The "Turnkey" package includes the "Basic design" plus: Plastic two-chamber windows laminated to look like wood Doors - wooden (pine) Floors Euro-board finish ceilings Roofing - soft bituminous (lining of overhangs) Sanding, antiseptic and painting

See "prices"

Question 4. What wood and log diameter is better to use for building a log house?

The Modern Wooden Houses company uses logs of pine and smereka (European spruce) from the Carpathian growing region.

Comparative characteristics of pine and European spruce (smereka) wood:

The strength and density of pine and smereka wood has a slight difference, and in the construction of supporting structures (for example, piles and beams) are used equally. The texture of the spruce fibers is more uniform and less tangled, the knots are small. The uniformity of the fibers and the lack of difference between the heartwood and sapwood allows the log to dry with less internal stress than pine, because spruce does not have a clear heartwood boundary. Resin pockets, which make pine "ooze" for a long time, are small and not ubiquitous in spruce, so the wood is white, uniform and beautiful in appearance.

Regardless of the preference in the choice of wood, we produce rounded logs in the range of 180-240mm. For example, for country and bathing needs, as well as summer houses, logs with a thickness of 180-200mm are enough. If you are planning a house for year-round use, where it is important to avoid heat loss, it is advisable to use a log with a diameter of 220-240mm. This increases the area of adjoining surfaces in the lunar groove. Even this is enough if, after shrinkage between adjacent logs, where gaps can form, caulking is performed, after which heat losses are reduced significantly, and the house will delight the owner with its efficiency for a long time to come. Therefore, we recommend houses made of round logs be sure to caulk after shrinkage.

Wall log processing

Mechanical processing of logs
When calibrating a rounded log on a machine to obtain a “correct” shape, a significant part of the thickness is cut off. The log is not perfectly even, so it is turned until the workpiece is straight. Be sure to remove the bark and cambium. In order to obtain an even diameter of the log due to the initial curvature of the tree, unfortunately, a part of the bast is cut off, where the wood is denser than in the central part of the trunk, and which has protective properties in the log. Therefore, in order to obtain a round log diameter of 240 mm, it is necessary to cut at least 250 mm thick at the thin end, and the rest goes into sawdust.

Advantages of natural logs. Preparing for installation in the wall

Manual processing of logs

If you are planning to build a handmade log cabin, the SDD company offers hewn logs with a diameter of 260-360mm. If the log is polished and planed by hand, then the shape of the log remains natural, only the bark and cambium are removed, and the protective layer of the bast remains. The difference in the thickness of the butt and top ends is also preserved. When the logs are laid into the wall, the thin top and bottom butt ends alternate to compensate for differences in the thickness of the trunk. This work requires extraordinary skills and accuracy: it is here that the true professionalism of the masters of the company "Modern Wooden Houses" is manifested.

Lunar groove requirements for manual fitting:

A handmade log house is warmer and more durable than log houses. Whatever the thickness of the logs, the fit area in the wall is less than their main diameter. The lunar groove allows you to slightly increase this plane, but its main task is a snug fit and precise fit. It is very important not to overdo it with the deepening. If the groove is too deep and reaches a significant part of the core or, even worse, the core, then there is a huge risk that under the weight of the wall with shrinkage of the house, this log will not withstand and will burst under load. The optimal ratio of the depth of the lunar groove, according to construction experience, should be no more than 1/6 of the main thickness of the log, or about 15 cm.

Comparative table of works on two techniques for the construction of log cabins

Question 5. Is a log house protected with an antiseptic?

The SDD company produces wood protection with a triple layer of antiseptic.
The first layer is applied after grinding during installation in order to process the junctions of logs that will not be accessible while in the wall.
Further, after assembling the structure, the surface is cleaned of dust and 2 layers of glazing tinted antiseptic are applied, which is finishing in the decoration of the facade.

Question 6. What is the warranty for wooden houses?

Modern Wooden Houses gives a 5-year quality guarantee for the assembled wooden structure and offers further post-warranty service under a service contract, which allows you to perform caulking, shrinkage adjustment and seam sealing. At the request of the client, the log house can be treated with UV protection and waxed.

Read more about additional work in the article Service maintenance of wooden houses.