The construction industry has always used wood in many residential and commercial buildings. However, wood is typically used for the interior parts of buildings, while steel and concrete remain the main structural frame materials, especially for skyscrapers.
Nonetheless, there is an emerging trend for tall wooden buildings, which you can find in many parts of the world. For example, the Council on Tall Buildings and Urban Habitat released a study stating that by 2019, there will be 21 completed timber buildings. These buildings will have a height of more than 50 metres.
The increasing demand for greener buildings gives the construction of taller wooden buildings a boost. Moreover, there are recent advances in the technological capabilities of wood, with the development of wood products that are stronger and more durable than traditional timber.
Reduction of carbon footprint
With the issues of climate change and global warming continuing to be a threat, governments and various industries are working together to find a means of reducing their carbon footprint. They want to do this by avoiding the use of steel and concrete in construction. Internationally, there are movements for greener built environments. There are already several revisions to the International Building Code. Among the modifications is the statement that wood, including the new wood products like mass timber, can be used safely as the main support structure of buildings as high as 18 storeys.
This means that more wooden skyscrapers will be seen in the UK and many other parts of the world. We will see more tall wooden buildings with innovative designs, using new wood materials that can withstand harsher environments.
New wood products for modern wooden buildings
Many architects are predicting that there will be a higher demand for wooden buildings as new wood products become available. Most facilities will be using steel and hybrid timber structures. Researchers and engineers have worked on technological developments in heavy timber construction. The availability of new wood products encourages more builders and architects to use wood as a more ecologically sound, sustainable and renewable material for buildings.
1. Mass timber
One of the biggest developments was mass timber, which is short for massive timber. It is touted as a strong, low-carbon substitute for steel and concrete. Mass timber comprises multiple solid wood panels glued or nailed together, creating a wood product with excellent durability and strength. With the changes in the building code, it is now possible to use mass timber for 18-storey buildings.
However, the UK has reservations about wood-framed buildings. Presently, the government allows the construction of wood buildings that are three to four storeys high. This is because the authorities want to avoid another catastrophe like what happened to the 24-storey Grenfell Tower.
2. Glue-laminated timber
This second-generation mass timber is available in standard and custom sizes. You can have them in depths of 15.2 cm to 182.8 cm and widths of 6.3 cm to 27.3 centimetres. In addition, you can order glue-laminated timber (GLT) in lengths of over 30.5 metres. Architects use them for pitched and curved applications, such as vaulted ceilings. Aside from its aesthetic appeal, you can use GLT as cantilevers, floor beams, purlins, trusses, and roofing and floor decking planks.
But while these new wood products are synthetically fortified, do not forget the rich and unique beauty of naturally aged wood, which you can use for structural and decorative purposes. For example, you can check out www.greenbarntimbers.co.uk and find a wide range of reclaimed timber that can enhance a building’s interior, providing additional surface texture and focal interest.
3. Cross-laminated timber
Popular in Europe as it was developed in Austria and Germany, cross-laminated timber (CLT) is now gaining wider attention worldwide. The material comprises planks (lamellas) of sawn, layered, and glued wood. Each layer is perpendicular to the previous layer. The method of layering makes the CLT structurally rigid in both directions. CLT is similar to plywood, but the components are thicker. As a result, CLT panels have excellent compressive and tensile strength. CLT wood is available in 3-ply and 5-ply panels.
You can use CLT panels as floors, walls, roofs, ceilings, and furniture. CLT thickness and length can be custom-made. Generally, the panels are pre-ordered and will be assembled and cut at the fabricator’s site based on the specific design requirements. They will prepare the material, anticipating the joints, drills, and openings, so assembly onsite is quicker.
4. Acetylated wood
Acetylated wood uses radiata pine from New Zealand or Chile, soaked in acetic anhydride. The process makes the wood exceptionally resistant to rot, insects, and moisture. Acetylated wood is more durable compared to pressure-treated wood. The wood does not swell or shrink. Thus, sealants and stains remain longer. However, acetylated wood is imported, so it costs higher. Moreover, only stainless steel screws can withstand its acidity.
Other wood products are available for different purposes, such as nail-laminated timber, dowel-laminated timber, and glue-laminated timber.
5. Nail-laminated timber
Nail-laminated timber (NLT) uses dimension lumber, with screws or nails fastening the individual laminations together. You can use NLT for walls, roofing, decking, flooring, stair shafts, and elevator shafts. Architects also use it for exposed-to-view or decorative applications, such as cantilevers and curves.
6. Dowel-laminated timber
Dowel-laminated timber (DLT) is a type of mass timber that provides superior architectural flexibility. It is more suited for horizontal spans, such as roofing and flooring. DLTs improve visual appeal when used for kerfs and curves. It is also excellent in enhancing acoustics. You can leave the DLT exposed to add a range of attractive finishes to the surface.
The resurgence of wood buildings
There is definite proof that wood buildings will be next on the horizon for the construction industry. Of course, many countries already have wood buildings, but the structures of the future will be using newer wood products that will be more resilient, durable, and stronger than natural wood.
The industry highly anticipates one building, the Sumitomo Forestry’s W350 Tower, which will rise in Tokyo in 2041. Sumitomo Forestry will construct the 70-storey hybrid timber building to mark the 350th anniversary of the company.
The future wood building in Japan will be much taller than the 18-storey Brock Commons Student Residence in Vancouver, Canada. Norway also recently unveiled its 18-storey, 85.3-metre-tall Mjøstårnet Tower. The building houses office spaces, apartments, and the Wood Hotel.
Under construction in Vienna is an 83.82-metre building. While in Milwaukee in the United States, the Ascent, a 25-storey mass timber building, is already under construction.
There is also a proposal to build an 80-storey wooden building in the UK, which will become a part of the Barbican Centre. The building will be called the Barbican Timber Tower. The proposal, submitted in 2016, is still under consideration.
You can already foresee the future, where wood buildings will once again grace the skyline like in the past. However, there will be a big difference, as the modern wood buildings will be using engineered timber. The products are more resilient, stronger than natural wood, and can withstand harsher weather conditions. With special coatings, the new wood products also have fire-retardant properties. As fabricators can customise engineered timber to designers’ specifications, construction time will be shorter. Using timber will create new demand to care for existing woodlands and develop new ones.