Exploring the Advantages and Drawbacks of Glued Timber Houses

Glued timber houses are being constructed and successfully operated in many countries including Sweden, Finland, Austria, Germany, Czech Republic, and Russia.

Glued timber is a relatively new construction material that challenges traditional views on wood. It is in demand for the construction of private houses, cottages, saunas, and other countryside properties. It is made from solid softwood species (spruce, pine, oak, beech) by gluing individual lamellas into a single mass. The material is based on boards dried in a chamber for 10 days. To form timber logs, glued blanks are pressed under pressure. The result is lumber with a homogeneous structure and high operational parameters. More information on how glued timber is made can be found here.

Compared to a wooden house, a similar brick structure requires more substantial financial investment. Due to the lower density of the material, a wooden house weighs much less than a brick one. Thanks to the low specific weight of glued timber (600–900 kg/m3), structures made from it can be built without the need for deep and heavy foundations. This significantly saves costs during construction.

Glued timber has a perfectly smooth surface and a presentable appearance, so it does not require the use of finishing materials. It is sufficient to emphasize the natural beauty of the wood with clear lacquer or, if desired, use a tinting agent. Additionally, glued timber is free from cracking issues. Since the outer lamellae in such timbers are placed with the core facing outward, this protects the external surface of the building material from the appearance of micro-cracks. This is because natural micro-cracks in wood often occur from the center towards the edges. Therefore, if they do occur, they will be located inside, not outside, the timber.

Brick conducts heat faster than wood, so a house made of this material needs to be carefully insulated. Climate in most European countries and North America is harsh enough, so one of the main characteristics of building materials is resistance to heat transfer.

This indicator is the same for walls made of glued timber 21 cm thick, aerated concrete – 29 cm, and brick masonry – 46-50 cm. Due to the low thermal conductivity of glued timber and the tight stacking of timber logs, the structures built from them are cozy and warm. They do not require large heating costs, retain heat well in cold weather, and provide coolness in summer. Heating savings compared to brick or round timber houses reach 40%. Usually, only the floor and roof are insulated in glued timber buildings.

Regardless of the chosen technology, a wooden house is built within one construction season. If a glued timber house kit is used for residential construction, the construction takes 1-2 months. Moreover, such constructions can be assembled year-round, and suitable weather conditions are not necessary to wait for. The possibility of rapid construction of such buildings is explained by the high precision of glued timber manufacturing with strict adherence to temperature and humidity conditions.

Unlike solid engineered timber and solid logs, glued timber is thoroughly dried in special drying chambers and has a relative humidity of 8–12%. Thanks to this, houses and other structures made from it have minimal shrinkage – up to 1%. Therefore, internal communications in such buildings can be installed immediately after their construction.

For comparison, ordinary logs have a humidity of about 18-22% and, on average, shrink by 6–12%. Glued timber confidently maintains its geometry and dimensions, resists deformation, and forms a monolithic structure.

This is another advantage of glued timber. Due to its manufacturing from natural wood, glued timber is completely safe for human health and pets, contributes to creating a comfortable microclimate, and does not emit harmful substances. Although glue is used in its production, it is environmentally safe and also possesses antiseptic properties.

During the manufacturing of glued timber, wooden lamellas are carefully fitted and tightly compressed, and adjacent layers of wood with different fiber directions are glued together. This assembly and gluing technology of the wooden structure provide the material with high strength (50–70% higher than solid wood), resistance to significant loads, and various negative effects. Load-bearing structures made of glued timber are stronger than reinforced concrete. Therefore, the span length of structural beams can be increased, expanding the space of the rooms.

Seismic resistance of the building is ensured by the tight connection of all elements, so the house withstands underground shocks and powerful wind loads.

When using quality materials and adhering to the construction technology, glued timber houses can serve their owners for many decades, maintaining their operational characteristics. Unlike solid wood, this material is resistant to fungal infections, decay, and the appearance of wood-boring insects, so it lasts much longer. During the manufacturing process, glued timber undergoes antiseptic treatment, acquiring a high level of protection against biological decay.
According to many experts, such houses can serve for a very long time, and without significant operational costs – they need to be treated with protective compounds approximately every 10–15 years.

For this purpose, channels are drilled in the timber. Wires are laid in plastic corrugated pipes or flexible embedded cable channels. For increased safety, you can run stainless steel cable pipes - this will greatly increase the fire safety of your home.

Due to the absence of gaps and cracks in glulam beams, it is difficult to ignite. To ignite glued timber, it is necessary to apply powerful directed flame for at least 5 minutes. To increase fire resistance, wooden building materials are treated with fire retardants. Moreover, unlike concrete, brick, or foam block, glued timber does not collapse to the base when burned.

The facade of such a house is beautiful without decorative processing. If desired, only the surface of the exterior walls can be painted. Typically, no additional finishing is required, which reduces overall construction costs. The walls of a glued timber house can be treated no more than once every 10-15 years. The surface is sanded, impregnated with antiseptics, then a primer and paint are applied layer by layer.

The most significant downside of glued timber might be its price, which is explained by the complex and expensive production process and the excellent operational characteristics of lumber. But this disadvantage is relative. Glued timber, unlike solid wood and other materials, does not require expensive finishing, so these expenses are excluded from the total costs. Final cost of glulam house is usually lower than one for the frame house, or brick-concrete construction of the same size.

Another drawback of glued timber is considered to be the presence of dense layers of glue in its structure, which allegedly affect its ecological properties. If safe adhesive systems are used in production, the resulting material does not have a harmful effect on health.

The need for periodic treatment. To prevent aging, the building needs to be treated with protective impregnations. A properly maintained building will serve for many decades or even centuries.

When comparing the pros and cons of glued timber with the indicators of other materials, it is worth considering the savings achieved due to the advantages of the technology. For example, a timber house will be cheaper than a quality frame, brick, or stone one. The absence of the need for external finishing and insulation, the risks of shrinkage and deformation make it the best choice for reliable construction.

Building a house from glued timber will also save on labor costs. If desired, all work can be done independently - DIY. In frame and brick buildings, oriented strand board (OSB) is often used for laying rough floors, attics are insulated with synthetic insulators, and vapor barriers are installed in the rooms. All of this affects the ecological properties of the building in one way or another.

Glued timber houses represent an attractive and efficient solution for building both rural and urban properties. They possess several significant advantages, including moderate cost compared to brick houses, lightweight construction, low interior finishing costs, low thermal conductivity, fast construction speed, environmental safety, high strength, and durability. Thanks to these qualities, glued timber houses are becoming increasingly popular in the construction industry.

Glued timber is the most advanced material in the 21st century, combining the qualities of environmental friendliness, strength and durability. Add to this the aesthetics that you get when building a house from timber - you will get a unique in its qualities building that will please you for many years.