We've been experiencing an issue across the floor on one half section of the house where there are discoloration spots across the floor. Moisture meter reads high- anywhere from 40-80% on spots with discoloration and 8-20% on rest of floor. Floor sits on concrete slab. The material of floor is Engineered Wood.
What baffles us is there's no plumbing underneath floor- all plumbing is above ceiling. Even irrigation drains run around the house, i.e. on sides parallel to house not directly under floor. There's no buckling of floor/seams or uneven ness.
So I'm looking for some help to find out what could be causing this issue. Any help is appreciated.
See pics (sorry for reflection from sun).
Best Answer
So you must realize that although there is no standing water anywhere on the ground below the floor there is moisture (a vapor). Concrete can be thought of as a sponge in that it will absorb moisture (water) and allow it to move through it.
Most concrete slabs have a plastic vapor barrier (sometimes) installed on the ground, but not always. If the wood floor was glued to the slab and moisture is transferring from the ground this is what is causing the water stains and there is no easy fix.
On the plus side the wood is not swelling (looking at the photo's) and the staining appears to be limited (although it's hard to see). Perhaps a darker colored floor stain would hide the marks. Is the wood becoming loose or warped?