Glue Lam Over Concrete

smadax

Thrown a curve ball this week...

Floors are radiant heat & tile has already been installed... can't put in subflooring w/o noticable sized step. Need vapor barrier, can't glue directly to the concrete. Can I glue the t/g and float the floor? If so, would you recommend 1/16" foam underlay??

Floorwizard

Please tell me which product you are putting down.
this is not a locking tounge and groove?

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"in 20 years you will regret more what you did not do than what you did"

smadax

Its'a glue lam strand floor, non-locking tongue and groove.

The plan to date is poly vapor barrier and glue the T&G... concerned as this is not my prefered method of installation, it's questionable. I'd prefer to lay a subfloor or sleepers, but can't put any additional height on the floor.

Floorwizard

it would be amazing if glueing only would work with the t&g properly. the floor is going to move around quite a bit and that glue is not strong enough to hold it unfortunately.
Sounds like you have to install proper subfloor or pick out another product.
If you take the risk you may be ok but chances are you will not be happy at all with the results.
I have seen engineered wood glued with standard tounge and groove and a flexible adhesive....Anderson hardwood does it...but your material is quite different and more unstable.

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"in 20 years you will regret more what you did not do than what you did"

Mike Costello

check with the manufacturer to see if the floating method is ok.

I have done this on numerous times with success

Floorwizard

You have floated solid hardwood according to manufacturers recommendations? Or did you take the risk and so far everything worked great?

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"in 20 years you will regret more what you did not do than what you did"

smadax

The manufacture set up this installation and failed to gather proper information, we were not aware that the floors were concrete w/radiant heat. They also did not know that 2 types of flooring where being installed in this area and we're now having to match the tile floor levels.

The manufacture said to glue T&G... have never done this before and worried it won't work. Think it would be advisable to draft a contract with the manufacture to prevent liability for this floor if it doesn't work?

I like the idea of gluing the product directly to the concrete, but need the vapor barrier. Lose-Lose.

Mike Costello

I misunderstood, I thought we were talking engineered here

My bad

Mike Costello

Boy, if you can get it in writing somehow that would be cool.

Its been my experience that it varies from product to product as far as gluing the tounge and groove. I have seen specs one one product that says you cant then another that says its cool. Both appeared to have the same milling so I cant direct you on what to look for.

I still have all my old laminate strap clamps and as long as you dont over crank them they worked pretty well keeping things tight.

smadax

Update from the manufacture... we were told there is a particular membrane that we can glue to the concrete, then glue the strand flooring directly to the membrane. That sounds better than just glue on the T&G.

Mike Costello

Dependable Cut Down?

Be sure to check your adhesive about the radiant heat

Floordude

Bostiks MVP moisture barrier and Bostiks BST adhesive

or

Mapei WFM moisture barrier and Mapei 990 adhesive.

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Floorwizard

I agree with Floordude

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"in 20 years you will regret more what you did not do than what you did"

smadax

After careful consideration this was the route I was headed, until we hit a brick wall with availability. The main flooring product supplier HIGHLY recommend BEST because of the guarantee... but I do not like the fact that it slumps. MVP is available, but BST is not and would take too long to wait for shipment from manufature.

Another product that was recommended is STAUF-960
Has the same characteristic and specifications as MVP/BST combined, but it's a polymer base. Anyone have expereince with this product?

PrecisionFloors

I personally have not used the Stauf adhesive but I have heard great things about it from other installers who have. Namely the characteristics you are looking for. I wouldn't hesitate to use if it is available.

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Floordude

I'd like to use Stauf 960, but I have yet to find a distributor that carries it around here.

How about Bostik's TKO????

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smadax

Hm, never considered the TKO, what is it?

Apparently the glue of any kind is not readily available in my area, one supplier said they've had the one can of Bostik and Stauf sitting in their warehouse for a year! They really flog the Bostik Best because of the warranty.

I've decided to go with the Stauf and I'm happy with it. I especially like how easy it is to clean up and that it doesn't have the toxic urethane fumes. The price is insane $399 CAN/4 gal bucket, whereas the Bostik was $199/5 gal (retail prices)