We will be installing solid ash strip flooring, pre-finished with micro-groove, over radiant in 1/12†concrete. We will be attaching directly to 2X sleepers placed at 1’ intervals. The main floor (not a slab) is over the basement below which has radiant in the slab. The heat on the main level is on at a modest level, all concrete was poured approx 2 yrs age. Drywall finished months ago so major moisture is not a concern. The flooring has been on site for many months and has been acclimated.
Questions:
- Moisture, should we still do a poly vapor barrier? (note: the concrete was pulled flat but not troweled so the surface could puncture the barrier)
- Sound Proofing, would using it impede heat transfer from concrete to wood thus rendering the system less efficient? If not, is some types more preferable for radiant heat?
- Attaching / installing, since it is over radiant, we are looking for as much holding power as possible. Should be use square cut or staples? Should we use adhesive to assist nails? If so, are there any that are better than others for radiant? Definitely interested in the least noxious.
Thank you for any assistance you can provide.
Replies
go to http://www.hardwoodinstaller.com and visit the message boards. they have some very knowledgable poster there. it sounds like you already have the wood so i bet you are dead set on using solid. however, i think an engineered product would have been better. i would see what they recommend though.
Thanks, I'll check it out and yes we have the wood already
As I understand it, you are installing the strip flooring over an inch and a half of lightweight concrete? A few things you might want to consider are: 12" is a long way between nails on a plank floor. The 2x sleepers are soft so you may want to add a dab of PL Premium to supplement the nails. I wouldn't glue across the entire width of the plank. I think the staples hold as well as the nails so it doesn't make much difference what you use.
One of the worst problems that I see in a situation like yours, is the concrete not being perfectly level with the tops of the sleepers. If it is too high in spots, we have to grind it. If it is too low, which is likely if they just dragged the concrete, you will have the flooring supporting weight over an 11" span and it may creak or crack when it starts to dry and pulls away from the adjacent piece.
I prefer to keep the concrete very slightly below the sleepers when we pour because they will dry out and shrink. I trowel thinset over the concrete and screed off of the sleepers right before we install the flooring. This gives you a very solid, smooth and even base for the flooring.
Thank you for the advice. We did have to grind so high spots in the concrete. I don't see any low spots. I'm not sure there would be room for thinset. I'll have to take a look at it The concrete is just ever so slightly below the sleepers.