Moisture Barrier Needed - which one?

[sawdust250]

I want to install engineered hardwood or bamboo on the slab on the ground floor of my house. I ran the calcium chloride moisture test in 3 areas and got readings of 5.8, 5.6, and 10.35.

I was thinking of using a floating install with sound deadening underlayment. If I use titebond 531 and put 6 mil plastic, under the underlayment will that protect the wood floor from the moisture so the floor doesn't fail?

Thanks!

 

[DarisMulkin]

Isn't the 10.35 quite a jump? Even for glue down carpet they say no greater than %.

Daris

 

[Ernesto]

Use six mil plastic and sound solutions with attached vapor retarder for double protection. The 10 may be a fluke test depending if you prepped correctly.
Terragren likes you to use titebond finger and groove glue only. It works very well.

Edit: lol finger and groove.....T&G

 

[sawdust250]

Thanks for the replies. The high result may be due to problems with the seal on the dome of the moisture tester. I'm going to use the 6 mil plastic and the sound solutions under the floating floor.

Is cutting slits in the back of the baseboard to let the water vapor out overkill? I was going to lap the plastic up the wall behind the baseboard. Thanks again. Jonathan

 

[Ernesto]

I have thought about that same thing. But if you run the plastic up the wall it will be plastered to the sheetrock when you install the base. Not sure how you would keep paint and dust out of them as well.
If you want cut the plastic at the floor. There's basically no science or pedigree of study behind that requirement that you run any vapor retarder up the wall.