You’ll never guess what the building material of the century is—probably because it’s under your nose, and your home is already made of it. It’s wood.
But, it’s not your average Home Depot 4x4. It’s more complex than that. This is Cross-Laminated Timber (CLT) (similar to Glulam), or its simpler alternative called Nail-Laminated Timber (NLT).
If you haven't a clue about these wood products, we've gone into detail about engineered wood flooring.
Well, CLT is a similar product to engineered wood flooring. However, the main difference is that architects can make almost anything out of CLT: staircases, apartments, and even high-rise buildings!
CLT and NLT products have been getting a great deal of attention in North America. There have been a number of all-wood high-rise building reveals in Vancouver, New-York, and Portland. However, CLT and NLT need not be relegated to high-rises. A number of European countries have welcomed these products into the residential sector long ago.
What Are these Mysterious Wood Products?
Image of a Cross Laminated Timber Panel courtesy of APA - The Engineered Wood Association.
CLT comes in panels constructed by stacking and gluing about 3 to 7 layers of kiln-dried lumber boards together. The boards are stacked in alternating directions at 90-degree angles for strength. Depending on the manufacturer, you can find full panels between 60 to 98 feet long.
Image of a Nail-Laminated Timber Panel courtesy of StructureCraft.
NLT is not a new technology. Previously known as “mill decking” or “heavy timber”, NLT was a choice material 150 years ago because of its simplicity, and strength. Planks of wood are nailed together to form panels, just like CLTs. NLTs are typically cheaper than CLTs.
Both products have quick building assembly times, especially in comparison to steel and concrete. CLTs and NLTs are good for load bearing expanses, such as roofs and ceilings. They are also strong enough to be used as structural walls. Their overall aesthetic makes them great for interiors, and exteriors.
Architects appreciate CLT, NLT, and engineered wood products for industrial builds because of their sustainability and utility. As architects continue to push for the wooden high-rise in North America, homeowners should take advantage of these amazing materials on the market.
CLTs and NLTs can come pre-fabricated, or in ‘sheets’ that are assembled on the construction site. The material is always manufactured in-factory, and has been designed with precisely measured cut-outs for electrical outlets, windows, and doors. This method allows homeowners to have custom built homes out of earth-friendly, and sometimes local materials. These materials truly make house construction a breeze!
Image of a Cross Laminated Timber Panel courtesy of StructureCraft.
For example, one CLT cottage in Ottawa was constructed in only two days! Builders even soured the CLT from a company located in Quebec. This Vancouver home was the first North American home to use CLT as the main building material. It took six days to assemble on-site. It would have taken at least 4 months to complete a conventional home on that property!
Shorter building time helps you save money on labour costs. All-wood buildings usually require more carpenters than an assortment of experts. This cuts down the number of workers, and the labour costs. Several experts have argued that CLT and NLT products have a competitive price on the building material market in comparison to concrete and steel. When you factor in the cost of labour, the time to build, and the positive environmental impact that these products have, CLTs and NLTs have huge benefits in the building industry.
Why Should we use these Products?
CLT and NLT high-rise buildings may be new to North America, but architects and builders choose these materials for a reason. Wood is a flexible material that stands up well to lateral compression. These engineered wood products have the same strength as normal, and re-enforced concrete!
StructurLam explains that their CrossLam product is 6 times lighter than concrete, and takes up 1/3rd the amount of space. This means that teams can construct buildings quicker with these wood products, in comparison to concrete and steel. It’s much quieter and safer to build with wood products on-site. And, they take up less space on-site, and inside the building.
Image of a Cross Laminated Timber Panel used as a roof courtesy of APA - The Engineered Wood Association.
CLTs and NLTs are praise-worthy for sustainable reasons as well. Wood is ‘carbon-sequestering’—meaning that it traps carbon from the atmosphere, and contains it. When wood naturally decomposes, it releases this carbon back into the world. Utilizing wood instead of allowing it to decompose is an important step reducing green house gas emissions. In fact, one manufacturer called StructureCraft, mentions that CLT and NLT products sequester between 1643 – 1655 Kg of CO2 per tonne!
These products have low carbon footprints. Steel and concrete take a great deal of energy and resources to produce, which accounts for their very high carbon footprint. Wood is a recyclable, renewable resource with a long lifetime.
Interestingly enough, CLTs can be made from gluing smaller trees together, rather than relying on old-growth trees. This feature makes these wood products great renewable and sustainable options to build with. Finally, there are Forest Stewardship Certified (FSC) products available on the market.
These engineered wood products have been deemed fire safe. Lighting mass wood on fire is very difficult, despite popular belief. CLTs and NLTs are naturally slow burning products that have added fire protection, thanks to non-combustible materials such as gypsum.
No wonder the UK architect Andrew Waugh says, “this is the beginning of the timber age"!
*Cover photo image courtesy of StructureCraft.