okay to use pl300 to glue plywood to concrete?

[Forrest Gon]

I have got a very small concrete landing area (about 4ft x 4ft) which needs to covered by subfloor so laminated floor can be installed.

Can I just use some leftover loctite pl300 to glue a piece of plywood to the concrete or I have to use some more specific glue for this purpose? Thanks

subfloorglue.jpeg

[Rich Engelhardt]

Can I just use some leftover loctite pl300 to glue a piece of plywood to the concrete or I have to use some more specific glue for this purpose? Thanks

I did a ton of research on this before I installed the oak stair treads on the cast concrete steps leading from my family room up to the garage.

A special adhesive, like Bostik Best is what you need. It's both adhesive and vapor barrier.

The horrible part/news is - the stuff is so expensive & because it's a flooring adhesive, it doesn't come in small containers. I had to buy a 4 gallon pail ($250) and I used about 2 quarts.

[Alex Zeller]

I thought Pl 300 was for foamboard. I used PL 400 under the cement board I attached to my subfloor in my house under tiles. Never had a problem with it.

[Mike Kees]

PL 400 . It will be a permanent bond. I have used PL 400 to glue down wood to concrete for years. It was how we always fastened bottom plates to basement floors when there was in floor heating lines in the concrete.

[Rich Engelhardt]

Put white (untreated) wood (including plywood) on concrete & it will rot.
That's why it's against code.
You have to use either pressure treated or install a vapor barrier.

[Dave Sabo]

what does the label or MDS say ?

[Mike Kees]

Rich is right. We were gluing down PWF bottom plates on top of basement floors. You can get PWF plywood for your application. Sorry I was not more clear about the treated lumber aspect to begin with.

[Steve Rozmiarek]

Rich is right on this in most circumstances. If the floor is above grade though and poured over a good moisture barrier, you would be fine with wood glued to it. In that instance, you would use pl400, not 300. Looks like a perfect place for some vinyl plank.

[Bill Dufour]

Why not a few nails and gravity?
Bill D

[Forrest Gon]

Thanks guys, Ground Contact Pressure-Treated Plywood is the PWF you guys refered, correct?

[Mike Kees]

Yep. that is the stuff.