Radiant Heat Overlay on Existing Slab-on-Grade
I am converting an existing unconditioned garage with a concrete slab-on-grade to a conditioned mudroom with hydronic radiant floor heating and stone tile. The top of slab is approximately 7″ below the planned finish floor elevation. The project is in Pittsburgh, PA, and my main concerns are tile cracking, moisture management, and radiant heat efficacy.
My approach is to add the following layers, from bottom to top: One-coat epoxy resin system for moisture management, adhered rigid insulation (2″+) for insulation and to build up the floor level, plywood layer for attachment of PEX tubing, ~2″ gypcrete slab for encasement of tubing, floating/uncoupling membrane, thinset, tile.
Am I missing something? Is any of this overkill? Simpler way to do this?
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