Help! My father and I installed a hand scraped 5/8 th inch engineered bamboo floor over a concrete subfloor. Carpeting was previously on the concrete floor. We spent a lot of time on the prep work of the concrete. We scraped off all glue and thoroughly cleaned concrete. We applied leveling compound in areas of necessity. We allowed drying time. We then applied Bostik Vapor moisture barrier as directed by Lowes. (not cheap) We allowed the bamboo to acclimate for 3 weeks prior to use taking it out of the boxes and stacking it tinker toy fashion to allow for air flow. We then used Bostik adhesive (again recommended) to glue down bamboo. We had a CCT test done by Lowes contractor. Floors are now buckling and moisture found underneath. Bostik rep and Lowes rep came out yesterday and stated that it was our fault that contaminates on concrete were the cause not allowing the vapor barrier to adhere!? Also that this bamboo was not a good choice for Oceanside California even though they sell it 2 blocks away. Flat dont know where to turn now.

 

I installed the same bamboo floor over my concrete slab but I didn't remove the old vinyl tile I had down. I put down the thickest padding for bamboo floors I could find and them free floated the bamboo floor.

I creaked and moaned for a few weeks and now it is just fine. I can expand and contract with the weather and want buckle.

I live in Oklahoma and have a wet climate most of the year but not as bad as you have in California I bet.

Maybe free floating will help you.

 

Wendyn123, welcome to the forums! Was a moisture test done prior to installation. This is usually done with a 2' x 2' piece of clear plastic taped on all edges to the concrete for a couple of days. If you have moisture droplets on the plastic, you will have moisture in anything you put on top of it. Was the engineered floor click lock or not? If click lock, why was it glued?

 

You used the moisture barrier... With the correct trowel.
You had a Calcium Chloride test done... But no test results for the 3 tests that should have been done per 1000 sq.ft.

Concrete has the ability to be below dew point temperature.

If the contaminates were not removed from the concrete surface prior to prep and installation like both the floor patching material and the adhesive states, then that was the weak link, that let go, when the flooring swelled from a gain in moisture content.

If the flooring was acclimated during the winter months and installed tight during the winter, the flooring will gain moisture from the higher rH in the spring months and swell. Compression cupping and then, pop goes the weasel, if it is not bonded well to the substrate.

 

The installation of the moisture barrier is only warrantied up to a set amount of vapor depending on the exact system you use. Plastic sheet method is okay but not quantitative so it gives you no hard evidence. calcium chloride is good but some V.B. companies do not recognize this test anymore. In-situ relative humidity tests (RH) are more often the prefered test from Bostick or Koester or anyone else who sells a V.B. Without the test to prove that your levels where below the allowable levels you have no defence against Bostik. What was the reading on the CC test? Will Bostik recognize the CC test or do they require the RH test. In addition to this fact you have to make sure your installation was per the Bostik specs and typical V.B. specs call for a shot blast or acid etch of the floor to remove contaminents, open the concrete pores and insure adhesion. You stated thay you throughly cleaned the floor; that tells me that you did not shot blast or acid etch the old surface and as such you probably gave Bostik the wiggle room they need to walk away from your problem. Sorry but I think you may be out of luck.

 

This doenst sound good as I was considering bamboo flooring also. First comes to mind is the quality of the material. Exactly how thick if the bamboo veneer. What is the substrate? Their are many variations and much is made in Asia, so the quality can really vary.
Can you post a picture?