Hi everyone,

I am in the process of installing bamboo floors but I just can't seem to find an answer to my particular installtaion

info:

Floor: traditional bamboo 5/8" (usfloors brand)
Substrate: concrete in apt building. 8th floor.

Done so far:

The concrete was prepared with SLC to level it out. Later I applied redgard moisture barrier and covers it with speed finish skim coat. (Adhesive does not bond to regard) but over the cementous patch anything can be installed according to instructions on speed finish. (It bonds to redgard same company)

I have cork underlamyment 1/4" that I want to glue down for sounds suppression and on top of the Cork glue the bamboo floor.

Q1. Can I use Roberts 7250 cork adhesive to glue the cork down? (Instruction are confusing if using wood floor as finish surface)

Q2. Should I use Roberts r1535 adhesive to glue down the bamboo to the cork? Or some other adhesive? (R1535 is for bamboo and cork is an okay substrate).

Q3. Or should I use r1535 for both cork to concrete and bamboo to Cork ? Or thats an oberkill, its much more expensive.

Q4. instead of Roberts use bostik best for bamboo to Cork (can't confirm if bostik best can be applied over cork)? Or any recomndations you guys have would be great.

Thank you for your time.

OOPS! Redguard is not for moisture vapor emission control under hardwood on slabs. It's primarily made for moisture intrusion under tile to prevent moisture from getting down into substrates. Thinset sticks to it because thats what it is designed for.

You need to grind it off. Or maybe float the floor.