Glulam - history, technology and application

Modern technology time and again offers new and new materials to builders, which they could only dream of earlier. One of them is a timber, which is made from wood (not even the best) and special glue. Today it is no secret that this lumber has become the strongest and most reliable among natural. He is well established in various global markets and is actively used by many construction companies. In the article we will learn in more detail how the glued timber is made, what it is and where it is applied.

A bit of wood theory

Any wood has several advantages:

• low thermal conductivity;
• small weight;
• appearance;
• environmental friendliness and benefits for our body.

It has been used in construction since time immemorial. But very often the “stumbling block” was the geometric instability of products. The period of shrinkage inevitable for sawn timber harbored great surprises, and not pleasant ones.

For example, wood:

• wrecked;
• twisted;
• arched;
• cracked.

Therefore, at the turn of the 20th century in Finland, large construction companies were ready to invest in the development of new materials that could completely eliminate the problems of its geometric instability.

History of laminated veneer lumber

The revolution in the global construction market occurred with the advent of laminated veneer lumber. It was a direct result of understanding the problems that were directly related to the shortcomings of wood. To say for sure today is difficult about the author of this technology.

One of the versions is the pressure of nature conservationists, who called on everyone to use natural resources as economically as possible. Although the second has the right to exist - the usual shortage of wood in the Scandinavian countries, caused by the fashion for natural building materials.

The emergence and wide dissemination of technology has also contributed to the development of effective adhesives, which made it possible to obtain a "solid" beam, using several components. The 70s in Finland are considered to be the official entry into the construction market for laminated veneer lumber.

The sawn timber is made of condom pine, which in Finnish is called “honka”. This type of wood compares favorably with other similar ones. Using glued timber 150x150 mm or 200x200 mm, the Finns refused to frame the construction, which, in their opinion, had many drawbacks, one of which was considered the lack of a natural effect in the house.

The material showed by example that it allows construction companies to simplify and speed up the process of building log cabins from timber. In addition, now there was no need to wait for the shrinkage of the building before finishing.

The beam allows you to combine the energy of wood, comfort and microclimate of a classic wooden house with a modern approach to construction work, where one of the main factors is speed. Due to this, the erection of buildings with the use of this timber quickly conquered the world market, and the instruction for each house set made each a builder.

Glue

The main environmental indicator of houses from profiled timber is the degree of safety of glue used for bonding lamellas. Often there are manufacturers for whom the possible profit is much higher than the health of consumers of their products.

When gluing in production using toxic substances. Below we will tell about what glue is used for glued laminated timber in the manufacture.

Wood is a natural material and has positive environmental performance. But with the increase in the number of new technologies in the field of wood processing, they are steadily declining. At the same time, the quality indicators are significantly increasing, and the operational characteristics of sawn timber are improved.

Glued profiled timber - one of these representatives. Most opponents of its use refer to the use of low-quality glue in its manufacture.

Lamella lumber is used not only for the construction of residential buildings. It is often found in the form of supporting structures for indoor stadiums. In this case, the safety of the surrounding manufacturers do not care, so they use any glue, saving significant funds.

There are a number of international standards that share adhesives for the safety of their use. For example, if lumber is used for housing, it must comply with EN 204/205. All other adhesives can not be used in the manufacture of timber for the construction of residential houses due to the presence of substances harmful to the human body.

In the manufacture of glued construction timber use:

1. Melamine;
2. Resorcinol;
3. Polyurethane.

There is also an epi laminated timber, which uses a polymer adhesive for bonding. Any of these compounds is considered safe and can be used for residential housing. High-quality adhesive must have two certificates - international (FMPA) and Russian (GOST 17005, GOST 15613.1).

In addition, each glued bar must have a quality certificate indicating the degree of safety of its use in the construction of residential buildings. Every solid company is obliged to have them.

Tip: if you are in doubt about lumber, you can always make the appropriate examination on the safety of the glue.

Glued or plain timber?

Low-rise construction due to these sawn timber acquired the appropriate gloss. Very often, elite cottages are built of glued laminated timber, the price of which is quite high.

But is it worth spending money on a new material or is it better to look for cheaper options? What is the difference between laminated timber and laminated timber? Consider each material separately.

Plain

Building material derived from a single piece of wood. Usually it has flat or chipped faces, and its cross section is square or rectangular. Make a bar, as a rule, from coniferous breeds.

Due to its low cost, it has become widespread among consumers, which can be attributed to its positive qualities. But, since it is a natural material that can "breathe" throughout life, it has significant drawbacks.

Cons of conventional timber:

1. It is very difficult to be dried to the required moisture content of a large section beam. This, in turn, is necessary in order to guarantee the absence of internal stresses and deformations in the wall;
2. There are hidden defects located inside the beam array. They are the root cause of cracking and deformation after the material is installed in the wall;
3. It is difficult to get the perfect timber with a large cross-section. This is due to the fact that the trunks of trees have defects and bends.

Glued

Timber of new generation which succeeded simple bar. Thanks to new technologies, there are not many flaws in it that correspond to ordinary materials, what is the difference between a bar and a laminated bar. The basis of the glued timber are thick pine boards glued together under pressure into a single product.

Drying

Necessary for the manufacture of boards dried to the required moisture content, which is much easier to do than with a massive log. As a result, lumber does not have such a percentage of shrinkage as any other material from wood.

Piling

The reliability of the product is achieved by laying the boards on top of each other with multidirectional fibers. To avoid outdoor cracking, they are placed in the middle of the beam core. In addition, it distributes the internal loads in the timber.

Assembly

To facilitate the assembly and increase grip, sawn timber is cut using the thorn-groove system. Cut them on special woodworking machines, mill ends.

disadvantages

High price, compared with other sawn timber, as well as manufacturing complexity. Sometimes the boards are peeled off or their selection is not made in good faith.

Tip: when ordering and buying material be careful, especially when the product is a little-known seller.

Beams

During the construction of a wooden house there are always a lot of questions that imply subtleties of installation. For example, you must first carry out accurate calculations to prevent the destruction of the house. Interest from developers often causes a system of overlapping of glued lumber.

Есть и другие варианты – бетонная плита или массивные бревна. Однако, первая достаточно дорогой материал, а на массив нельзя положиться на долгое время. Beams из клееного бруса дают фору и по стоимости, и по механическим функциям.

They are sold in construction markets next to doors, windows and other lumber. Some European countries use them in more than 80% of the house overlap. In Russia, this timber was used as beams not so long ago. Let's try to understand their pros and cons.

Sling system

It is a complex structure responsible for the strength of the roof and interfloor joints, i.e. the whole house.

Beams перекрытия из клееного бруса применяют в домах, изготовленных из различных материалов:

• wooden;
• brick;
• concrete.

Timber is easy to assemble, inexpensive, easily accessible and up to 12 m long. In addition, the unsupported span can be more than 6 m, beams do not bend.

Advantages and disadvantages

Positive qualities are:

1. Durability and reliability of timber give the chance to make a design with the minimum quantity of support.
2. The low weight of the glued timber does not make the house heavier, which allows not to build a powerful foundation.
3. Profitability, as in many cases the production of the same products from another material is more expensive.
4. Durable, does not require special care.

Negative user reviews:

1. If the quality of the beams is poor, lamellae can flake and burst.
2. The material can not be called 100% environmentally friendly.
3. It will be difficult to install the truss system without additional equipment.

The above list shows that the main drawbacks concern the manufacturer of glued beams. Therefore, with his right choice, the design will serve not one decade.

Conclusion

Building technologies do not stand still and constantly offer new solutions. The article told us - what is glued timber, how it appeared and where it is mainly used.

We also received the concept of adhesives for its production and their safety for our body. In the presented video in this article you will find additional information on this topic.