Replies

1. Expert Member
   Dana Dorsett | Dec 12, 2018 05:00pm | #1

   With a plywood or OSB subfloor there are no issues even with fairly high water temps. With plank subfloor there might be a bit of seasonal movement with a more expansion/contraction of the planks than non-radiant floors, but not really "warping".

2. 
   rhl_ | Dec 12, 2018 05:39pm | #2

   Thanks !

3. 
   BrianPontolilo | Dec 12, 2018 08:59pm | #3

   Ryan,

   In general, wood expands and contracts across the grain as moisture levels change. So, you're floors are going to move in relation to humidity changes in your home. Boards cup when one side is much wetter than the other. If you have somewhat stable humidity in your house, including above and below these floors, they should be stable. I don't expect in floor heating to have too much of an effect if other conditions are favorable. I've heard a lot of opinions on this question, though, and know that some wood flooring installer insist on vapor retarders with in-floor heating. Maybe we'll hear from someone with some real life experience.

4. 
   Jon_R | Dec 12, 2018 09:39pm | #4

   > some real life experience

   You could take a sample of the exact flooring/underlayment you are considering and set it on a warm hot plate for a month. Measure for flatness and dimensional change.

5. Expert Member
   Akos | Dec 12, 2018 10:12pm | #5

   I've had issues with solid bamboo flooring over heated floors coming apart (bamboo swells/shriks a lot with moisture).

   Just check whatever flooring you put on top is rated for heated floor application.

   I'm not a fan of staple up and plates. It is way too easy to put a nail through the pipe underneath without noticing. I would recommend a system that either keeps the pipes away from the subfloor or is sturdy enough to handle a nail. Also be careful with the pex you use, lot of them squeak a fair bit when they expand, annoying to live with.