How to insulate between slab and subfloor

Old 11-15-17, 06:26 AM
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How to insulate between slab and subfloor

The floor of my new mudroom/foyer consists of a 4" concrete slab with 5" tall sleepers. What is the best way to insulate such a floor? There is 2" foam and a vapor barrier beneath the slab and at the slap perimeter (slab ledge and 2' around perimeter) and vertical insulation on the interior face of the foundation wall. There are 6 cavities and one of them will have an air duct running through it as well as a copper water line to feed a spigot on the exterior wall. Considering the slab is insulated underneath and beneath that is soil, do I need to insulate under the floor at all?
Old 12-12-17, 02:59 PM
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I would not insulate - the heat duct combined with no insulation might serve to warm your floor a little.

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