No, it's much closer to Glue Laminated Timber whereas plywood tends to be made of wide sheets of thin timber of varying quality (depending on the quality of the wood and number of sheets glued together). CLT and GLT/glulam aren't made in sheets like plywood, they're usually constructed for a specific purpose (beams, etc.)

- https://vicash.com.au/cross-laminated-timber-vs-glue-laminat...

CLT is literally plywood with thicker lamellae.

I use this stuff when I design and build LEED-Gold certified hydroponic food production buildings. CLT is made out to panels and then cut to customer specifications. It has the same construction (including 90-degree off-orientation of each layer) and pretty much the exact same manufacturing process.

Glue Laminated Timber has the same orientation all the way through. It is meant specifically for one-direction loading (primarily structural support beam but can be done for joisting as well) whereas plywood and MDF and CLT will handle multi-directional loads (and is why it gets used for the outside skin of buildings framed with wood.)

But plywood is made out of veneer sheets that have been turned on a giant lathe. There is only a very thin layer of fibers running one way, you can't really see growth rings in a layer of ply. CLT layers can be at 2" thick or more, with a very definite grain structure and growth rings.

Which makes me wonder how CLT is supposed to behave with wood movement when atmospheric moisture changes. Is it made from a species of softwood with very little movement? Or is the adhesive supposed to be strong enough to withstand the stress under movement? Or has the wood been treated with some industrial process to reduce the movement? All of the above?

Cross laminated timber goes against everything I know about wood movement as a woodworker. But the only exposure I've had to this stuff was beating 6 inch thick (3 layers) CLT pieces with an axe for firewood. I'm really curious how this stuff can work.

"But plywood is made out of veneer sheets that have been turned on a giant lathe."

Ditto CLT. My class was making this almost 25 years ago back in high school wood shop, we just called it "Thick ply" and we primarily used it back then for constructing ultra-solid subwoofer boxes for vehicles. The lamellae were cut to 1/4" thick sheets on a lathe (they do make saw-based lathes, we had two in wood shop, one industrial one, one made out of a table saw with jigs for making dowels and such) planed, cut, oriented/glued/layered, veneer layer applied, sanded, then a final heat treating process, and done.

Your post shouldn't have been killed. Your comment is the same as the last sentence in the summary on wikipedia: "It is similar to plywood but with distinctively thicker laminations (or lamellae)."

Welcome to HN, China of the internet. You get disappeared and only allowed to speak when the people in power say you can.

Yes. Tricky thing is plywood uses veneers (very thin pieces) because wood expands at about a 10x different rate in width versus length, so cross-laminated joints can be subject to an incredible amount of stress. The thin veneers cannot develop enough stress to break the glue joint.

> so cross-laminated joints can be subject to an incredible amount of stress

OK, plywood overcomes the stress by having very thin laminates. So how does CLT overcome the stress due to different width vs length expansion rates? Shouldn't the problem be much worse with thick laminates?

So, in a sense, it is a form of carbon fibre.