I have a room (below grade) on a slab here in Portland, OR. It had an engineered cork floor, installed at the suggestion of the contractor. It was really gorgeous and softer and warmer underfoot than wood or Pergo.
Water vapor passes through any concrete slab. Over time, water vapor condensed below the floor, saturated the underlayment, and caused problems that proved costly to fix.
Unless you are in a dry area and your outbuilding has a perimeter drain and excellent moisture barrier, I’d be very careful about any flooring that won’t let the water vapor through. There are products made to raise flooring off the slab, and I guess they are used in commercial construction, but I am uncomfortable having moisture accumulate at all. However, they would let you use Pergo or something like that.
We had the slab ground down, a densifier applied, and eventually settled on an all-synthetic pad and carpet for the room. There has been no further moisture problem. Any water vapor is taken up by dehumidifiers (set to 45%).
I am not an engineer, and I can’t provide real construction advice -- this post is meant just to alert you to issues you should discuss with a specialist in on-grade flooring. In my experience, a general contractor and the floor manufacturer were NOT reliable sources of advice.
I don’t want to forget: Enjoy your space! It’s wonderful to have one that large!
Water vapor passes through any concrete slab. Over time, water vapor condensed below the floor, saturated the underlayment, and caused problems that proved costly to fix.
Unless you are in a dry area and your outbuilding has a perimeter drain and excellent moisture barrier, I’d be very careful about any flooring that won’t let the water vapor through. There are products made to raise flooring off the slab, and I guess they are used in commercial construction, but I am uncomfortable having moisture accumulate at all. However, they would let you use Pergo or something like that.
We had the slab ground down, a densifier applied, and eventually settled on an all-synthetic pad and carpet for the room. There has been no further moisture problem. Any water vapor is taken up by dehumidifiers (set to 45%).
I am not an engineer, and I can’t provide real construction advice -- this post is meant just to alert you to issues you should discuss with a specialist in on-grade flooring. In my experience, a general contractor and the floor manufacturer were NOT reliable sources of advice.
I don’t want to forget: Enjoy your space! It’s wonderful to have one that large!