Folks
I’m putting 3/4″ x 2-1/4″ strip flooring over Warmboard (grooved underlayment) with radiant tubing over 3/4″ ply insulated subfloor. As it’s on the second floor there should be no moisture problems. My questions are:
What wood species are stable and appropriate over radiant? I’m seen the various hardwood and flooring sites that seem to recommend Walnut, American Cherry, Hickory, and Pecan. I wanted to go with plain sawn Brazilian Cherry (Jatoba), but these same sites call it relatively unstable. This material is beautiful and the price is great. Does anyone have experience with it over radiant. Is it really unsuitable? Would I be risking a gappy, possibly cupped floor?
What species would you recommend? White oak is reasonably affordable (I’m tired of red oak). Is paying the extra dollar a foot for quarter-sawn material really worth the money?
Also, because of the tubing, I’m hesitant to put an opaque vapor retarding material like kraft paper over the subfloor. I’m afraid of smacking a nail into the tubing. It’s a bear to fix. Instead, I was thinking of using clear poly. The floors are all insulated. I can’t imagine the poly capturing and condensing moisture, especially with the heat. Any comments on this?
Thanks – Drew
Replies
Hey Drew, Let me know how you made out regarding species and installation technique. I have similiar concerns for my own bathroom renovation. Thanks for sharing any info. Shotsy
In 2002 I did a radiant heat job - staple up - with TJI's, 3/4 subfloor and then 3/4 Brazilian cherry on top. The flooring supplier warned about radiant heat on this floor but I did it anyway.
However, I designed the system to run at 100 degree water temperature, no higher. I did this by using extra 1/2" pex. This isn't much higher than the ambient temperature here in the Denver area in the summer, so I was not too concerned.
We have been thru one winter and so far so good. The recovery on this system would be slow, but they keep the same setting year round.
One other factor - there was no wall space available for baseboard - I had no choice.
Lots and lots of discussions on this topic. Go to the Advanced Search (link is near the top of the left frame) and enter
hardwood radiant
in the text box. You may have to hit the search button several times, and you may have to wait 15 or 20 seconds.
WRT the quartersawn oak, with such narrow strips, quartersawn versus plain sawn is going to make very little difference as far as expansion goes. So the thing you have to decide is do you like that flaky figure enough to pay extra for it.
Hi Drew,
I recently researched using radiant heat under 3/4" solid hardwood flooring. I have concluded that it is NOT the best thing to do. I used to import by the shipload Brazilian products, mostly exotic veneers and sold them by the truckload to places like Dixie-Ply, Georgia-Pacific and Bassett Furniture Industries. Spent a lot of time in Brazil. However, I paid attention to what the mill owners in Brazil said about the flooring because I was going to start importing them as well. I've been out of that business for over 5 years now. Former spousal unit got the business with my blessings.
Generally, 3/8" solid hardwood of Jatoba and Ipe will be more stable than 3/4" and best to keep widths to less than 4". I believe installation recommendations from most of the suppliers of these 2 species is to pre-drill, glue and screw over at least 15# felt. rolled cork is even better underlayment particularly for better sound insulation between floors. See: http://www.naturalcork.com or http://www.corkdirect.com
American Walnut is an entirely different species from Brazilian Walnut [Ipe]. American is softer than oak, while Brazilia is almost 3 times harder.
I'm going with Ipe flooring from Brazil which is different from what some suppliers are calling Ipe from different parts of the world especially in the decking. It will be finished on-site, which althought more difficult, it will have a more consistent finish throughout the house and be sealed from wall to wall. Pay attention to the moisture levels in the wood and subfloor before installation. Follow all instructions carefully.
Use only water based stain and poly finishes on Ipe and Jatoba.
Perhaps some of the pre-finished versions, such as from Bellawood, would be more suitable for use with radiant heating....I don't know. Rec'd a sample of 3/8" prefinished Ipe made by Bellawood last week. Finish is splotchy and shows fingerprints which may be why it's a sample...not sure.
Do keep in mind the weight of many of the exotic species. Ipe, for example weighs TWICE what american oak weighs. Can your 2nd floor hold this weight?
I would definitely use radiant heat under tile.
Good luck,
CATinGAmtns
Brazilian cherry over RFH is just what I have in my house. 3200 sq ft of it over staple-up.
What...7 years now? Not a problem.