Features of building a house from a profiled bar

Recommendation points

• How to choose the right type and variety of timber
• Moisture, aging and wood processing
• The foundation of a modern wooden house
• Is there a better felling method?
• What time of year to build?
• Crown and floor
• Building a box at home
• Slabs and roof

Despite the emergence of more and more sophisticated building materials, natural wood is still highly regarded among Russian developers. Profiled timber in this regard is very technological, especially if you need to carry out construction at an accelerated pace. Let’s talk about building a house from a profiled bar.

How to choose the right type and variety of timber

Profiled timber is classified according to two characteristics: the shape of the side faces and the profile of the butt joint. And if the choice between a flat or semicircular edge is made purely for aesthetic reasons, then the method of joining the crowns completely determines the strength, stability and energy efficiency of a log house.

Practitioners of cutters often agree that there are three preferred beam profiles: a comb, a Finnish tenon-groove and a double groove with oblique edges. In work, all three types are very convenient, the difference lies in the caulking method and the insulation material used, or its absence. So, when laying a bar with a comb, the seal is either not used at all, or a pre-compressed sealing tape (PSUL) is rolled between the crowns. For other types of connections, use jute cloth or felt.

It is advantageous to use the indicated types of profile due to the minimum values ​​of the divergence of the rims during the shrinkage process. Wedge-shaped spikes and grooves, unlike rectangular ones, are capable of sealing on their own. Another key difference of the comb can be called the impossibility of sealing the inter-joint gaps after shrinkage, while the tongue-groove is more tolerant of felling flaws and can be re-caulked..

The quality of the profiled timber is determined not so much by the origin of the forest as by the season of its felling and the correctness of the cut. The timber is usually cut from the core of the trunk, as can be easily seen from the location of the growth rings. The more precisely the longitudinal axis of the bar corresponds to the location of the core, the less likely it is that through cracks will occur in it. By the way, their presence is not at all a sign of bad wood quality. For profiled timber, cracks are a characteristic phenomenon, especially for lumber that has undergone intensive drying..

Moisture, aging and wood processing

It is possible to make a log house without aging only if it is made of laminated veneer lumber. Unfortunately, the price tag for this type of sawn timber can be 2–2.5 times higher in cost than ordinary solid timber, so many developers have no choice but to select, deliver and prepare timber before construction.

According to the relative moisture content, sawn timber is divided into natural (50–80%), construction (20–25%) and low (less than 15%) humidity. The catch here is that the thicker the material, the more difficult it is to dry it to the very core. It is due to the initial removal of moisture to values ​​of 10-15% that the timber loses its tendency to intense warping and twisting, although shrinkage phenomena are still characteristic of it. This is the advantage of laminated veneer lumber: it consists of thoroughly dried lamellas, which, moreover, are oriented with fibers in opposite directions.

Solid timber can be natural or chamber drying. In the latter case, dehydration with superheated steam and microwave irradiation will be most beneficial. Both of these methods lead to guaranteed destruction of organic matter that can develop over time and spoil the tree. For a pre-dried timber, moisture is not at all important at the time of delivery to the construction site and the start of felling, because the primary deformation processes in it have already passed.

It should be understood that the timber is usually dried prior to profile milling, which excludes distortion during subsequent storage and transportation. Damp cut wood can be distinguished by the smallest pile, which is pulled from the raw fibers during the passage of the cutting tool. And if the lateral surfaces of the profiled bar are usually ground to hide this defect, then such processing is not possible inside the grooves. A beam of this quality must be delivered to the site in advance, stacked in a pile or well with ventilation gaps and kept for 6-12 months. During this period, the wood will pick up and lose moisture several times, go through various temperature conditions and take its final shape.

After aging, the timber is sorted by curvature, treated with fire and bioprotective compounds, after which they proceed directly to the felling. When using a pre-drying bar, tricks with aging will not play a significant role, and a protective impregnation can be applied after the assembly of the log house. Glued laminated timber is usually not impregnated: if one of the lamellas is affected in the entire log house, then blue and rot cannot spread beyond it due to the presence of a glue partition.

The foundation of a modern wooden house

In contrast to a log house made of rounded logs, where one or several crowns are made with a forest of increased thickness, a house made of profiled timber is placed on a rigid concrete base. Slab foundations are the most suitable for wooden buildings. Due to their high stability, there is no need to give time to settle in the soil before accepting the design load.

Tapes and grillages on shallow piles require exposure from several months to a year, depending on the intensity of precipitation. The construction of a wooden house or a bath from a bar on an unstable foundation is fraught with the fact that, due to the uneven density of the soil and the significant weight of the walls, the tape will be skewed and the frame will have to be shifted. The exception is pile foundations, based on a deeper, denser and more uniform layer of soil, while the tape must go through 4-5 periods of prolonged rains, which will evenly wash the soil from both the inner and outer sides..

Is there a better felling method?

Due to the relatively small thickness of the profiled timber (again, due to the difficulties of deep drying), it is chopped into a bowl with the rest. Thus, dressing at corners and overcuts occurs according to the standard scheme in half a log..

By analogy with the trapezoidal spikes of the connecting profile, the Norwegian shape will be optimal for the bowl, and the Canadian shape for the thickness of the beams is more than 150 mm. A characteristic difference between the felling of rectangular sawn timber is the absence of sagging, although they may be present on the outer edges of D-shaped beams.

Canadian bowl

The Canadian and Norwegian bowls are capable of settling and compacting under the weight of the upper crowns as the wood shrinks. The notch of the countersunk spike at the bottom of the bowl is not necessary when using the spike-groove profile, but is highly recommended when laying beams with a comb. To prevent water from flowing between the crowns, the bowl should be cut in the upper position, since the low weight of the logs allows them to be freely manipulated.

What time of year to build?

Traditionally, a wooden house from a bar is cut in winter and there are a number of reasons for this:

1. The construction of the foundation is planned for late spring or early summer, when it is easier to carry out earthworks in thawed soil. Over the summer and autumn, the foundation has time to settle and endure the first manifestations of heaving without load.
2. In winter, wood does not draw moisture, and even vice versa – it reaches the condition of building moisture in the cold.
3. In a frozen state, damage to wood by insects and harmful organic matter is impossible.
4. After assembling a log house from a bar, its shrinkage occurs under changing weather conditions, making the tree easier to adapt to the shape, residual warpage and twisting are almost completely eliminated.

There is also a more practical reason to plan felling for the winter: most contractors take a break from the summer construction rush at this time, and the cost of their services is reduced accordingly..

Crown and floor

Although the frame of a log house from a profiled bar does not fulfill the function of a foundation, its structure has a serious specificity, on which both the durability of the house and the simplicity of its internal arrangement depend. It should start with the fact that for the first 2-3 crowns of a log house there is a bar of dense and hard conifers, for example, larch or fir. They are laid on concrete, having previously spread several layers of waterproofing. The remnants of the flashing beams are usually 15–20 cm longer than in the rest of the crowns.

Another characteristic feature of the profile bar flange is its attachment to the concrete base using anchor bolts. In this role, mortgage pins can also successfully act, however, this approach requires better organization and accurate marking. It is only important that the ends of the pins or bolts are recessed into the timber by 10–15 mm, for which wide pots are drilled under them. It must be remembered that for cutting in half a log, two directions of laying logs should be observed, that is, on one side, a whole beam goes to the cap, and on the other – a “ski” loose in half.

In houses on a tape or grillage, the beams of the first and sometimes the second row are often stacked after cutting the grooves on two opposite sides of each room. The grooves are designed to install a floor log, so the upper edge of the foundation has the smallest possible thickness, equal to the thickness of the timber, respectively, the consumption of concrete is minimized.

Building a box at home

In addition to the process of cutting bowls in the beams, there are several additional tricks when building a wooden house. The process of assembling a log house from a profiled bar is extremely simple: a sealing tape is placed in a groove or on a comb, then a bar of the next row is applied on top and upset with a sledgehammer.

To prevent twisting and warping, the crowns are fastened together with dowels. You should not use steel reinforcement for this purpose, because there is a high risk of moisture formation at the border of dissimilar materials. Also, an excessively tight fit of the dowels should not be allowed: their diameter must exactly correspond to the drilled hole (14–16 mm), while after driving the dowel is additionally recessed by 15–20 mm. The pitch of the installation of the dowels can fluctuate within 1-1.5 meters, while different rows must be fastened with an offset of 30-40 cm.

Cuttings are made to strengthen a building with walls over 6 meters long. They do not have to be folded with the leftovers, it is much easier and more efficient to cut the dovetail joint, avoiding additional gaps in the thermal protection of the house. Also, in this case, you have to perform the splicing of the bars, which is done according to the tension lock scheme with oblique edges.

As the walls are erected, window and door openings should be correctly formed. Before laying the next timber adjacent to the opening, its open end must be cut into a quarter. If the jamb is installed during assembly, the ends of the beams are cut into a thorn. It should be remembered that when installing glazing for the shrinkage period, the upper gap of the window must be at least 100 mm to ventilate the house.

Slabs and roof

Overlapping a house from a bar is quite simple to perform by analogy with the inset of a floor log. The difference may be that the floor beams are cut with the remainder. In this case, it is advisable to position the axis of the beam in the center of the inter-row seam, so as not to violate the integrity of the beams. The notch of the grooves should be performed no more than 2/3 of the thickness, firmly fastening both crowns with pins, between which the beams are clamped.

Depending on the steepness of the slope and the length of the overhangs, either the upper beam, which presses the attic floor beams, or any of the following, can act as a mauerlat for the rafters. In this case, the undercut is carried out exclusively in the rafter leg, which is installed with an offset in relation to the floor beam with the expectation that it will then be fixed to it from the side. It is widely practiced to gradually increase the length of the upper rims to form a wider eaves overhang..

The release of the remains of the beams outside does not have a very good effect on the thermal insulation of the house, but may be required if there is a significant load on the floor. Otherwise, this problem can be solved by attaching the beams to the walls using special metal brackets..