Insulating Floor System Over Conditioned Crawlspace
I’ve read that in conditioned crawlspaces, the floor (above the crawlspace) should not be insulated. However, I’m planning to install hydronic heat in portions of the floor and Siegenthaler recommends in Modern Hydronic Heating that hydronic floors above partially heated basements be insulated between the floor joists to R-19.
Which is correct in this situation?
I’m planning to ventilate the crawlspace by connecting it to the exhaust side of the HRV, pulling air in through floor vents on one side of the house and through the crawlspace to the exhaust tubing on the other side of the house. This would be about 2/3rds of the exhaust flow, with the remainder coming from the bathrooms.
I’m in climate zone 4C (Pacific Northwest) and plan to insulate the interior of the stemwall to R15 and the ground below the vapor barrier to R10. The heat source will be wood and/or propane boiler(s). The flooring above the hydronics will be a mix of tile and engineered wood. I’m still trying to decide between thin slab, gypsum, or a Warmboard type of product to encapsulate the tubing above the subfloor and would welcome any recommendations.
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