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joebuilderinc
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Discussion Starter · #1 ·
Six months ago my flooring installation subcontractor glued bamboo flooring directly to the concrete slab in a condo we were remodeling. All looked great for 3 months then in 1 room a large section of the bamboo flooring bubbled up about 6-8 inches off the concrete. I removed that floor and found that the grain in the bamboo had become darker and mold was growing. Several months went by and another room had the same problem. After inspection I noticed that grain in the bamboo has become very dark and the surface texture is detriorating and showing the wiood grain. Does anyone out there have a similar experience that they could share? This will cost a substantial amount of money to repair and we did a thorough analysis before we decided to glue down the bamboo directly to the concrete. I'm wondering if there is an existing problem with bamboo out of China.
 

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Flooring Guru
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Unless you can tell me the manufacturer, then it came from the Pacific Rim and that's about all we can know.
Problem is the concrete....
I never glue wood or grass to bare concrete....ever.
there is always moisture that will migrate up.....that's the problem.

complete replacement, and reinstall floating Bamboo over 6 mil poly.
 
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I do not believe this would be a problem with the actual hardwood flooring itself but more of the conditions that the bamboo flooring within the room. High densities of moisture or odd levels of room temperature may cause a bubble factor in the hardwood flooring itself. This could be due to not letting the bamboo flooring sit in the environment prior to installation to level for the condition. If you do not let the bamboo flooring sit, it will slightly expand causing the bubbling effect after installation.
 

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Knowledge Factory
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Sounds like a perfect case of concrete moisture penetration, into the bamboo. Bamboo will grow mold quickly.

What type of moisture blocker/barrier was appied to the concrete, before the glue was applied?:shifty:
 

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Yes, you have a moisture issue in the concrete. We seal all concrete slabs with Mapai WFM before glueing down bamboo or solid wood floors. Mapai Guarentees thier sealer for up to 10 years if you use thier WFM Sealer & Glue with new trowels. This guarentee is good for a moisture reading of up to 8 % using a tramex cme3 according to my local rep.
 

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joebuilderinc
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Discussion Starter · #6 ·
I appreciate the advice you all have given. Our installation technique was this: We sanded the floor with a 80 grit floor sander, then vacuumed clean. Then we layed down a layer of urethane glue and allowed it to dry. Then we troweled urethane glue andset the bamboo flooring. We only installed 7 planks width per day and we put weight on top of what we installed daily. All florring was allowed to acclimate for around 10- 14 days prior to installation. acclimation was achieved by opening the boxes and allowing the on-site air to envelope the flooring. The black mold appears to be eminating from the darker viens in the bamboo wood grain. The bamboo has changed to a dramatically darker color then when purchased. The dark veins have gotten darker and the surface texture of the flooring has gotten imperfect. Any new information and discussion would be appreciated.
 

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ian @antex western
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Floordude is on the right track, lack of good prior prep, sorry but this is looking like a take up and re-lay,

on the plus side with the problems you seem to be having, at least taking up the old should not present many problems
 

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It sounds like vapor emissions to me. Like the other said. If you're installation is in close to the water, you should try a couple of moisture tests. If they are high, like 8 or 10 plus, you need to bring in a sub to shot blast the floor, and install a good vapor barrier. We usually use stuff like Koester VAP-2000 or Synthetic 30. I know there is a synthetic rep in Honolulu.

But you need to run moisture tests 1st. I dont know for sure, but depending on the type of floor you are installing, it might require a cement topcoat to bond to, so you or your sub would have to prime the vapor barrier w/ an epoxy primer and then install a thin cement topcoat.
 

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joebuilderinc
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Discussion Starter · #10 ·
I really appreciate the quick responses. This site has helped immensely in narrowing down the possible causes and the techniques needed to resolve the issue in the future. We are removing the flooring then cleaning and treating the areas due to the mold growth. We think a 60 mil vapor barrier membrane followed by 18x18 ceramic tile will work. Any thoughts?
 

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I just noticed the OP is from 5-0 Whole different set of rules for wood out there...I remember reading an article on wood flooring in Miami,the local knowledge states"if your in the wood floor business...get out!!"
 
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