Basement slab healthy flooring options
I’ve read the articles on GBA re flooring concerns on finished basement slabs due to moisture issues, i.e., moldy carpet, tile/laminate adhesives breaking loose, etc. The floor sub-contractor acknowledges a potential problem in our area but believes my situation has no cause for concern. I’m looking for a second opinion from the knowledgeable folks here.
On the cold edge of Zone 4. New construction. Walkout basement walls are half concrete/half framing. Concrete walls received waterproof upgrade over damp-proofing. There is an upgraded, heavy-duty 15-mil vapor barrier under the slab. The lower level has its own HVAC with higher-end Carrier humidity control. Not a separate de-humidifier, but supposedly fancy programming & upgraded hardware to control humidity. Carrier says of the Performance 17 Model 24ACB7, 2-stage AC, “Compressor enhanced summer dehumidification when managed by Performance Edge relative humidity performance thermostat (will use Carrier Cor Wi-fi).” It is combined with a DC VSM furnace. I also have a PV system that will cover most of my electrical power needs so not too worried about running the AC for dehumidification.
The floor contractor believes there are no worries about moisture/condensation affecting the two options we are considering–carpet & floating laminate planks. He says the problems around here are from some combination of no waterproofing on walls, no vapor barrier under slab and minimal AC in a full concrete basement.
My missing ingredient is no foamboard under the slab or on the concrete part of the walls (the framed parts have R-25 BIBS). A relatively small part of the concrete wall areas have R-13 batts set in 2x4s but spaced 2 inches away from concrete walls. The foamboard was just too expensive to install. I realize that potentially leaves me vulnerable to condensation.
Should I have any flooring concerns? What would you recommend? Carpet is the least expensive. The interlocking laminates are double the price but I would do it if that would be a better long-term solution. Some of the laminate planks are claimed to be 100% waterproof and need no adhesives. Some we’re looking at have cork bottom layers. If we use carpet, then could do tile in two bathrooms. If we use laminate throughout, then I would only need carpet in the dedicated home theater. Thanks.
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