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Community and Q&A

Radiant heat and spray foam insulation

Banished1945 | Posted in Energy Efficiency and Durability on

I have just installed radiant heat under my deck that is now part of our living space. The area is 24 ft by 6 ft by 6 in and 2 ft of the ground. The pex tubing is attached directly to the deck with alum. heat
transfer plates with a 6 in space from the outside edges. My question is: can I spray foam over the
pex and plates without any airspace at all ?

Thank you

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  1. user-2890856 | | #1

    Yes . No more than 2" lifts with the spray foam though as besides the pex exceeding it's extrusion temp you could burn the house down . Make sure you have a truly qualified foam installer .

  2. Dana1 | | #2

    You can spray foam over them, understanding that you'll have a heluva time repairing it later. Using open cell foam rather than closed cell would make later access &/or repair easier, and you could install it in 5-6" lifts rather than 2". (It's cheaper and greener too- open cell uses half the polymer per R, and water instead of HFC245fa for a blowing agent.)

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