Never say never a builder call the other day about a wood job. At a condo they want a sound/crack/moisture underlayment its mapie 3 ft. rolls pill/stick first a primer. Look at floor will fix first check out tile guys seam to be stuck realy good. Said the tile guy would do it for me but thats all i need if they don't clean it good knowing they ain't gotta install on it. Got bostis best glue with 5" engineer maple. I like to go in wet but i thought i might sould let it set a little bit. Being that its moisture cured. Ya'll got any ideals? PLEASE REPLY! Don't know how to use the emoticons thanks

I am clear as mud on what you are trying to do here Steve .

Slow down and splain again what they want you to do.

Chuck knows alot about membranes, where is he???

Steve,

What product are you using from mapie?



You’re on the right track there. Engineered maple is a good choice for Florida. What floor is the condo on?



You can wet lay it. I personally prefer to wet lay.


Let us know the product from mapie that you are using as well you mentioned something about a primer. You may need a sound barrier if you are installing above grade you will have to check with the condo association. If you are on grade you may need extra moisture protection.

The product is mapelastic sm crack isolation/sound reduction membrane it comes in rolls 3 ft wide by 50 long The primer is water based roll/on. Its the third floor new building with one living floor below then garage right on ocean. Fixing floor will be flat. The thought of letting the bostis set alittle bit was because i thought it was moisture cured. I like going in wet myself. Not sure with membrane but rep for membrane said no problem he use to be Hartco rep know him long time what do you think? THANKS Steve

OK, Steve you are going to glue the mapelastic membrane to the floor using a water based adhesive most likely the mapelastic adhesive that comes with it. Then you are going to glue the wood to the membrane using Bostik’s. Am I correct?

I am no familiar with the mapelastic membrane but it sounds to me by reading up on it that it is more focused on tile installation. Everything I read mentioned installing tile over it. I would venture to say that it will be fine though as your are installing above grade. If there is excessive moisture in the floor then there is something really wrong. Just make sure your moisture test it. If the Condo says that the mapelastic is rated for their sound control requirements then I do not think it is going to hurt anything to be under there. What does concern me though is the fact that you will be installing the membrane with a water based adhesive and the wood will be installed with Bostiks. This creates a world of problems the first being that the two glues may have different elasticity’s allowing one to move more than the other. Further I would bet dime to dollar that the Bostik’s will be the stronger glue, which means if the wood does move it will rip the membrane and the other glue right off the floor. Remember the glue bond to the floor is only as strong as the weakest glue.

The membrane is pill/stick be first a water base primer tile guys seam to stick real good.The membranes alittle over 1/8 inch think .

I don’t know Steve I think the material will separate from the floor if the Bostik’s pulls it. You may want to adhere the membrane to the floor with some Bostik’s as well as its own adhesive. It is a tile product and I can’t find any information on the actual adhesive it is using to adhere to the floor. I found mention of latex but not whether that was the actual membrane or the adhesive. If it is latex it will loose the fight with a urethane glue.

How deep are your pockets?


The urethane adhesive is much stronger, with more pull then any peel and stick adhesive.

Your better off gluing cork with the same moisture cure urethane as your on the flooring.


If this is lightweight gypcrete, your comiting suicide!

I've never used anything but cork glued to the concrete with the same adhesive as will be used for the hardwood. I've seen the Mapelastic rolls before, but always being used by stone or tile setters as a CPE or crack isolation membrane to keep the stone from cracking as the slab settles. IF the builder and rep both say its good to go then its obviously been used before by them, I'd call Mapei and see what their tech help line has to say.