Ugly Blisters Can Ruin a Floating Floor – What to do?

It’s every home remodeler’s worst nightmare. You pay a small fortune (maybe liquidate the kids’ college fund?) to install a top of the line hardwood floor. Everything looks great. Then, out of nowhere, grotesque grayish blisters pop up all over the floor, as if the hardwood had contracted some ghastly, highly communicable African plague. Walking on these blisters pops them,
releasing the stagnant smell of finish.

What went wrong with my floors?

Likely, vapor emissions – from concrete or from some other source beneath the floor – caused
moisture to migrate into the hardwood to form these blisters.

If you fail to test your floor and subfloor for moisture, you set yourself up for a blister disaster.
Your heating system, for instance, can suck moisture from the slab just as the finish cooks,
causing all of the bubbleishness. Once these blisters occur — unless you want to leave the plague-
like bubbles in place — you have to scrap the project, rip up the floor, and replace it altogether.

To prevent this from happening in your home or rec room:

  • Use a hygrometer to measure humidity of both the wood floor and the subfloor;
  • The NWFA has installation guidelines;
  • Also, check out the manufacturer’s instructions.

When homeowners embark on “do it yourself” adventures, unexpected problems – like this
bubbling problem – often arise, creating havoc, missed deadlines, thousands of dollars of
unexpected costs, and outrage.

To save yourself the hassle and frustration, connect with the team at Elegant Floors at 650-961-
1339. We provide free estimates, and our Diamond-certified professionals can help you figure
out the best solution for your Bay Area hardwood floor refinishing, installation, or cleaning
needs. You can also connect with us at

The Slab Moisture Blues