Replies

1. 
   DocC_ | Oct 20, 1999 10:42am | #1

   *
   I'm designing a house for myself and I would like to place hardwood (red oak or hickory) over in-floor hydronic heat. I've read that this can be done. However, a friend in construction advised against it, stating that the thermal variations would damage the hardwood, causing buckling or warping. Can anyone offer me any advice?

2. 
   Guest_ | Oct 20, 1999 11:25am | #2

   *
   It's done every day. Sometimes it's done well. Sometimes not.

   The biggest concern (to me) is getting your radiant system tuned properly. What this boils down to is operating temp. The lower the delta T, the less "thermal stress" on your wood. If your installer runs tubing loops at max length, the water may need to run at a higher temp for the higher heating load on that loop. A portion of your floor (closest to manifold) will be subjected to higher temps than that at the end of the loop. Nothing tremendous, but I've heard of it damaging tile installations more then wood. Keeping loops to reasonable lengths, and having them all approximately the same length aids even heat distribution, and allows a decent operating temp, and allows the system to run comfortably between the max supply and min return temp settings. Most manifolds have valves where, if needed, you can throttle down the amount of water passing through it. A crude method to regulate individual loop temp/heat load.

   I circulate water at around 90-95 degrees. Never a problem. Both gypcrete and staple up. I know others that swear 120 degrees is just right. For me, cooler is better. We've all got our methods, they all differ, and of course, we're all correct and the other guy is always wrong.

   If you're truly concerned, you can opt for a laminated and/or floating wood flooring. The ply construction makes it more stable. Some look nice, and they're getting better each year. They install well. Typically they are prefinished, which may be good or bad. The number of plys and the thickness of the face ply will dictate how many times the flooring can be refinished. Not as much of a problem today, as coatings are more durable and "screening" is much easier then a total sand. Laminated product are much more popular today, and available in a wider selection of wood species than ever before. Also, for "real wood", quarter sawn is a bit more stable than flat sawn. You can also help yourself by comparing the stability of the species you are interested in and going with the one with the lower coefficient of expansion. Proper perimeter gaps will help as well.

   If he doesn't respond, hunt down Jeff (jjmcgough). I get the impression he's installed a heckuva lot more radiant systems than I have, and he's more technically versed as well. He may have a greater "data base" and variety of flooring installations over radiant to offer advice from.

   Congrads on your choice of radiant.

   With warm feet, Mongo

1. 
   Guest_ | Oct 20, 1999 02:39pm | #4

   *DocC,Check out the link Joe Fusco put in the "HARDWOOD OVER RADIANT" thread. It's got a lot of good info.Froed

3. 
   DocC_ | Oct 20, 1999 02:39pm | #3

   *