Use of special clearance along the axis of logs (undercut) in manual cutting of the house

Of course, the newly cut house on the construction site looks beautiful, if the logs lie one-to-one, without slits and gaps. Especially if you look at the ends of the logs in the corners of the cuts, in the window and door openings.

But the problem is that in this case, in 2-3 years, large enough slots are formed between the logs, which will not only ruin the appearance of your wooden house or bath, but, most importantly, will negatively affect the thermal conductivity of the log walls. This will require constant concoction, and, in the most negative cases, even special insulation of the walls.

Why it occurs? Let's consider in more detail. This is not an idle question: unfortunately, in many construction companies, even the masters themselves do not know about it and, especially, will not be able to explain to you how customers of houses or baths.

In order to prevent the formation of slits after shrinkage and shrinkage of the cut in Rus Log Company, the technique of creating undercut, i.e. clearance along the axis of logs, is used. This clearance is selected in the bottom part of the log along its entire length, and from the ends it is slightly less (5-8 mm together with the height of hanging of external corners, more details here), and, in invisible parts of the rim, slightly more (10-15 mm) see Figure 1.

Note that the peculiarities of creating an undercut for the lafet (semi-oval log) are discussed in a separate section.

Figure 1 shows the forces acting on the log during shrinkage and shrinkage. Due to these forces, first of all there is a crack in the bottom part of the log. It increases over time (Figure 2).

If initially there was no gap between the upper and lower logs, the edges of the slot of the upper logs would open as wings, forming significant longitudinal slots along the lines of contact of the logs.

In our case, the wings are also opened, but due to the gap there is a soft landing of the upper log on the lower log, and the edges of the slot even after expansion are close enough to the surface of the lower log (Figure 2).

Fig. 1		Fig. 2
		What this looks like in practice is shown in the following photos (Figure 3... 5). And don't be surprised if the sickle gaps between the logs (Figure 3), especially in the window and door openings (Figures 4 and 5 - unlike the end faces of the cuts, these openings will be further closed with carpentry products), now you know that this is a specially thought-out step of the masters of the company "Log House Rus", which will protect the walls of your house from the negative consequences.
Fig. 3
Fig. 4		Fig. 5

The resulted information is the intellectual property of " Log Russia".
At a reprint of materials, the reference to a company site is obligatory.