Saturday, February 1, 2020

Will CLT Make Its Way Into Modular Housing?

Another term I heard mentioned quite often at IBS 2020 was CLT. Not wanting to look stupid when asked about it, many people simply said “It’s good stuff but it won’t work in modular construction” without even knowing what the term meant.

CROSS LAMINATED TIMBER (CLT) is an engineered timber product that is actually pretty simple, but it has some massive implications.

Cross Laminated Timber or CLT is essentially construction grade lumber (2×4, 2×6, 2×8 etc.) that’s glued together to make a panel. The key part is that the middle layer is glued in a 90-degree cross layer. This gives the 3 layer panel strength in two directions, making it very strong. This also allows for the creation of large panels made up of relatively small pieces of wood.

What starts out as 2×4’s can be cross-laminated to make panels 10 feet wide and in some cases 70 feet long. The panels can also be made into more layers to create even more strength. They can be made into 5 layer thick panels.

They can be cheaper, quicker, cleaner and quieter to build than traditional structures. Over the past five years the use of CLT in construction has risen dramatically. The material is now being used to construct spectacular and sustainable homes, offices, schools and towers.

Often referred to as "super-plywood", the material is produced in a controlled factory environment from sustainable sourced timber., thus significantly reducing our carbon footprint. The wood is planed and kiln dried.

The conditioned timber is then stacked into layers, know as lamellas, on top of each other. Each layer is placed at a 90 degree angle to the one beneath. These layers are then glued, using a non-toxic adhesive, and hydraulically pressed together to create the high strength structural panels.

Using state-of-the-art Computer Numerically Controlled (CNC) joinery machines, almost any shape of panel can be produced, meaning that door and window openings can be pre-cut in the factory. These offsite manufactured panels are then ready to be delivered to site.

Proponents of CLT claim that producing timber building components consumes only 50% of the energy required to produce concrete and a mere 1% of that needed to produce steel.

CLTs are becoming a more prominent part of commercial construction and you have to think that it won’t be long until those 70’ CLT wall panels will begin finding their way into modular construction.

If not on the housing side in the near future, it will be showing up on the commercial modular side of our industry.

Now you have an answer if someone asks what you know about CLT. Go to the head of the class.


MARK WILLE said...

Big Fan of CLT and its applications. Glad to see you covering it here. I see numerous crossovers happening.

Arvind Vermani said...

Another very positive thing about CLT is that it has the potential of being carbon negative like other wood buildings (because wood sequesters carbon) compared to concrete or steel. In commercial applications this can be a big deal.

Studio Kiss / ASAPHouse said...

I have given a seminar about prefabrication to single-family residential architects and among the three main systems I cover is CLT. The seminar was NY State & USGBC approved for continuing education credits, and it is a good source for sustainable building practices and helpful in creating high-performance building envelopes.

Take a look here: