Application of metal couplers for connection of logs in notch bowls. German alternative to connection in "dovetail" and cramples

When we plan and project the log house, we wish it to be big and spacious, wishing to leave from close city apartments. Today houses with dimensions exceeding 8, 10 and even 12 metres on each of walls are not a rarity. But to find an equal 12 metre (is more exact 13 metre, taking into account length of corners) pine is a really good luck. But to find it is a half-business, it still needs to be brought on a building site. And here problems of basic or financial character begin, that does use of "long-lengths" (i.e. logs more than 6 metres long) economically unjustified.

So what to do? Our ancestors somehow left the given situation. Correctly, applying face connection of logs by a "dovetail" method (right picture). As a rule, all face joints of logs are done in notches and as the joint place is closed by the top log the impression of use of the whole log for a whole wall is made. Unfortunately, the "dovetail" knot has an essential lack - in time such connection cracks and also it is necessary to "wedge up" periodically that usually anybody never does.

Connection "dovetail" - it is NOT production of our company

As a result the density of corners worsens, there are gaps, the house loses integrity and walls can start to "float".

Use of metal building cramples (drawing on the right) became the modern decision used now by the majority of the building companies. As you understand it is also not an ideal decision. In fastening places there is a very strong pressure upon wood (the "tooth" area is small, and the weight of the top logs is considerable).

Application of building cramples is NOT production of our company

As a result crample "presses through" a log in contact places, there are gaps which are then reflecting on density of joining of logs in notches, and further there are problems already named by us above.

Besides, contact of steel cramples with a tree generates rust that results further in occurrence of bad sites of wood.

So what shall we do? As it is known, the genius of mankind always found decisions from, apparently, desperate situations. This problem has been solved also. As we already spoke, experts of the company "Log Russia" have a long-term operational experience not only for clients from Russia, but also for customers from the Scandinavian countries (first of all Norway), Spain, Germany and other countries of Western Europe.

Thus we always try to adopt all the best in world experience of building of wooden houses. So was with "curtaining of external corners" (this technique is now used seldom in Russia, though it is very effective) so became and with application of the zinced metal couplers for joining of logs.

These two listed approaches are present "know-hows" of the company "Log Russia", and, in aggregate with application of other technological approaches considered in given section, creates the unique competitive situation supported with a reasonable price policy of the company.

But let's return to our theme - joining of logs by the way borrowed by us at German colleagues.

In drawing 1 use of the coupler is represented schematically (the top view and a side view), representing by itself the zinced hairpin about semimeter long with carving on all length. The hairpin keeps within the narrow longitudinal saw cut, passing across a joint of logs. On the ends this cut has special grooves in the form of triangular prisms.

		The zinced metal washers are put on a hairpin from both ends, and over them are wound zinced nuts. Nuts are twisted with effort during installation of house, dense connection which will provide dense joining of logs in corners turns out as a result. Unlike application of cramples the bigger area of contact of a washer with wood is provided, so a much smaller pressure is transferred (pressure as we remember, it is force, divided on the area). Besides, zinced metal practically is not a subject of corrosion and will not cause wood defeat.
Fig. 1		Fig. 2
But not all is simple, especially, if we use the Canadian bowl and a dowel. Pay attention on the side view on fig. 1. Difficult enough system turns out. The hairpin should be deeply enough drowned in wood as over a hairpin the groove under a thorn laying above a log becomes. On the other hand, in the bottom part of a log it is necessary to cut a bowl and to put a dowel in it, and this dowel is placed in both joined logs. For a hairpin laying it is necessary to make a narrow and deep groove, its walls should be vertical and have strictly set sizes. Manufacturing of grooves in the form of triangular prisms also demand experience and qualification. Probably listed difficulties at work with a considered coupler and increased requirements to skills of cutters stop the majority of the building companies in application of the given technique. Nevertheless, the company management of "Log Russia" puts interests of the client above time difficulties with training of the personnel and widely applies the considered approach at building of houses to the customers.
Fig. 3		Fig. 4
Fig. 5		Fig. 6

In the drawings presented above 2. 5 use in practice of connection of logs by means of metal couplers is shown. As an interesting detail - in drawing 4 the nut and a washer, drowned in a groove are visible. Well and what are couplers, it is shown on a photo fig. 6.

By the way, pay attention, that in these photos it is shown a notch of a round log with an oval-flatten. It is one visit more card of our company, but more in detail we will tell about it in other section.

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