Glued laminated timber - the myths associated with the technology and adhesive systems

Story log houses several centuries, they have been all sorts of tests and time, and the people, and have proved their worth, although it has some specific properties. Construction of the laminated veneer lumber in our country can not boast such a spectacular experience, and despite the great popularity, shrouded in a whole set of myths. In this article we will focus on the most common "horror stories" associated with the adhesive, and the technology itself:

• Technology "young" - whether slat disperse.
• How bad glue to health.
• How effective is the glue - not a "debonding" Do bar in a few years.

Do lamellae disperse in the rod

Glulam produced by several longitudinal gluing wooden planks (slats) is used as a raw material softwood. The characteristics of this material depends not only on the adhesive system, but also on the parameters of the slats. So that in time bar is not divided into components, slats must meet the following criteria.

Operating humidity - a board after cutting (usually Lamella thickness 50 mm) is dried to acceptable performance - 8-15%, but the humidity adjacent slats must not diverge more than 4%. Exceeding these limits is fraught cracking timber after assembly structure to collapse the house does not fall apart, but the decorative and sealing definitely suffer.

Quality training slats - after the initial calibration (minus 1-2 mm) before gluing necessarily performed for finishing the calibration planer geometry at the exit must be nearly perfect. Permitted error is not larger than 0.1 mm per meter, unacceptable "wave" or torn fibers.

If the equipment is worn, blunt knives or sharpened, but not under that angle, properly handle the lamella will not work.

Although the voltage between the cut wood fibers removed allowing ready Brus avoid deformation when broken processing technology weld quality may deteriorate.

This will lead to disastrous consequences for the already constructed homes.

Oberon (User FORUMHOUSE):

Fine calibration is done before gluing to align the geometric size of the entire length of the board to get an accurate timber sizes. This is important for proper bonding and for the subsequent cutting to laminated veneer lumber domokomplekta details. Removed even 1-3 mm. If on the board remain neprostrogi - it must be delayed for reprocessing, gluing with neprostrogami not admissible.

However, certification of laminated veneer lumber, we volunteer, therefore tests carried out to prove the conformity of the product characteristics claimed, practiced in all industries.

To not worry about the durability of his house, it makes sense to choose a company producing lumber on the wrong or the service, and in accordance with GOST 20850 - 2014.

He is the most "fresh" and reflects the current requirements for the material.

In addition, products should be regularly tested in accordance with GOST 33120-2014 and GOST 33121-2014 or own laboratories (large enterprises), either in the laboratory outsourcing (specialized centers). The frequency of the tests - up to five times a week, the results are recorded and available for review. That is, high-quality glued laminated timber produced in compliance with the technology, according to GOST, regularly tested, and with the purchase of all the protocols can be found.

As for the "youth" of the technology, it is, on the contrary, has "middle-aged".

oberon:

Vouch for every house is unreal, but the technology exists since the fifties, there buildings (mainly industrial and public use) the Soviet era, still exists day. In Europe, test houses are located in the territory of one of the institutions, their track more than fifty years. While the "flight" normal. Tellingly, these houses are made specifically without antiseptic, as the main idea of ​​the study - to determine the behavior of the glue lines, not the wood.

Interestingly, in Switzerland and today operates a railway station, built of laminated veneer lumber in 1910, and in the main station building in Stockholm (1925) is the carrying out of glued laminated timber components, and glued slats still casein composition.

whether the adhesive is harmful in the rod

The technology of production involves several glue lines in each block, so the more likely potential customers concerned about the environmental friendliness of the material. Bruce made using a variety of adhesive systems, but most of it:

• EPI - emulsion polymers with isocyanate hardener;
• MMF - melamine-formaldehyde;
• PUR - polyurethane adhesive;
• PVA - polyvinyl acetate emulsion adhesive is prohibited for house building construction, since loses strength under static load.

Adhesive systems used in the manufacture of laminated veneer lumber, are certified and are environmentally safe, even if it's MMF. Any adhesive contains chemicals, however, if the adhesive quality, then all of it is polymerized (converted into solid) by gluing together timber. free formaldehyde content in the tool bar will correspond to national and European standards - EN 14080 and GOST 33122-14.

Unfortunately, to check whether the manufacturer uses a high-quality adhesive, stated in the documentation, or save costs and non-certified systems, or tactile or visually impossible. Therefore, in addition to domestic SES certification, the plant has to be a personal certificate of the adhesive manufacturer. The document will indicate what exactly is a company uses their glue, and that the staff is trained to work with the system. As in all things, in the selection of laminated veneer lumber operates rule of "trust, but verify."

oberon:

To continue not to worry about the environment - ask the manufacturer of Russian and international certificates for the adhesive used. Foreign certificate simply verify it specified email addresses which issued its institutions. Do not even speak the language, during the day actually find the information online translators to help them, and find out whether the certificate was issued.

The remaining doubts can be resolved by asking to arrange a tour of the company, if possible geographically - withdraw its name from the label to check that the adhesive is.

Do not beam debonding over time

There are situations when even later, not years, and for some time after the assembly to cut the bundle of bar clearly shows, it happened at the portal of one of the users.

Kac77 (Member FORUMHOUSE):

Friends built a large house of laminated veneer lumber, now because of the numerous low-quality assembly and pasted it is not clear what to do next. timber manufacturer and developer - one person who produced timber, and that it collected. The assembly made the first in 2013 in the fall, in the winter to gather under the roof, glazed, not heated in winter. During assembly, the box came under heavy rains, the roof assembly. Currently (summer 2014), numerous decomposes almost all the walls and cut through, around the perimeter of the inside and outside.

Although fundamentally nothing has not changed, and only relevant question is what to do, no less interesting, in order to avoid such, members of the forum called and the question of who is to blame. Seasoned members of portal, thoroughly versed in the subject, decided - a violation of manufacturing technology.

oberon:

One thing you can say for sure - not made according to SNIP and GOST, for such a bundle should not be in principle. Or after rain or after dancing with tambourines.

Owning a home recommend or negotiate with the company to eliminate at least the consequences (plaster, painting), or sue if they refuse. Everyone else - Carefully select the manufacturer, as compliance with the process and the use of high-quality adhesive system is the timber for decades, and everything rests, as usual, in human factor.

Timber produced in accordance with GOST, with proper treatment and lamella using certified adhesive systems - harmless and durable material for building houses.

Tellingly, in recent years it has become possible to build not only a low-rise private houses, but also public buildings taller buildings, which also confirms the viability of the technology.

All you need to know about laminated veneer lumber potential buyer - the topic at the forum, Oberon I opened it, even in 2012, but it is viable now. A lot of useful information - in an article about features houses from glued beams. In the video - about the intricacies Winter construction houses of timber.

Discuss the article and read other materials devoted to country life you can on the websiteFORUMHOUSE.

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