Hi, I'm using 5/8" bamboo on slab for a 60 ft² rectangular closet. Is the foam underlayment/moisture barrier such as used for laminate flooring an okay thing to float on?

Don

Yes it is OK to use it under any floating floor.

My question, is it recommended by the manufacturer, that this flooring can be floated with T&G glue.

Thanks Floorguy.

No, it's probably not recommended to glue up and float since it's 3¾" strip but I don't have the manufacturer specs. Since it's free wood, there's no warranty and no big loss if it fails. Also, it will see very limited travel with the direction of travel being perpendicular to the t&g joints. I can give it more than an inch to expand by putting it under both the base and shoe moldings. If you think this is destined to fail, I could glue to slab. Not a big deal since the floor is flat and good.

Don

Don,
If the bamboo is cross-ply solid it can be floated. To check it, look at the end of a piece, if the row of strips in the middle is in a different direction than the top and bottom row then you have a cross-ply solid that can be floated. If not then it will fail if floated.

It's very difficult to tell from the end grain but when also considering the difference in the edge grain, it appears to be cross-ply. Failure in a non cross-ply would be the tongues breaking off? Thanks kls.

Don

No I don’t think it would be that drastic. I think you would see glue breakdown from not holding and separation of boards.

Bamboo swells and shrinks, twice that of red oak.


It will eventually separate at the glue bond, in the T&G.

Yes, I can understand that. The stuff is porous like a wad of straws.

You reckon it's a lot mo'betta to do a solid glue down?

Don

Since you mention the subfloor being on 16'" centers why don't you nail it down? You must not have a gun? I would much rather nail then glue, good adhesive isn't cheap, but may be more accesible to you then a gun.
In a closet, with free wood, I would rather nail it with a stick nailer then glue it.

SK, I specified the subfloor is slab. Indeed, I'd nail it if I could.

Yikes, guess its brainfade. I skimmed that part about the direction of travel being perpendicular to the T&G, and my brain came up with what I posted. My bad....Yes i did also get the part about the slab, but sometimes you gotta wonder.