Shop with radiant slab heat: Do I need slab insulation?
Adam Emter - Zone 7a
| Posted in Plans Review on
Hi,
I’m planning to build a 40×96 shop with in-slab radiant heat. I will likely only heat to 55 degrees. I live in Central ND, zone 7a. Wondering if it’s necessary to use foam under my slab. Any thoughts?
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Replies
Any radiant installation whether it be floor , wall or ceiling requires insulation under , behind or above the tubing . This directs the heat energy toward the space to be heated and offers higher resistance than the material that energy must get through
Adam,
Q. "Shop with radiant slab heat: Do I need slab insulation?"
A. As Richard correctly pointed out, there is only one answer to this question: Yes. You need a continuous horizontal layer of rigid foam under the slab. In Zone 7, I would use at least 3 or 4 inches of rigid foam.
Don't forget: You also need vertical insulation around the entire perimeter of the slab.