3/4 skinny slab

Bigheadtodd

Have been asked by a builder to do a radiant heat job. Builder asked me if I had a problem with putting the 1/2 radiant tube in a bed of concreate only 3/4 inch thick.

His plan would be to do 3/4 inch tall sleepers with the tube and concreate in between on 16 inch centers. Above this would go another 3/4 thick plywood then 3/4 inch thick finished wood floor.

I have never doen this before allways been in 1.5 inches.Are there any waranty issues to consider etc?

Any way, anybody out there have any thoughts for me. Builder also wanted to know what if we dident use concreate at all. Be kind of like a stapel up except the tube would go on top of the sub floor.

If we don't use concreate what supply temperatures would I be looking at? This system would have 2 temps becuase part of the house would be in 1.5 inches of ligh weight concreat the other would be the dry system with no concreate.
there will also be domestic hot water.

Would like to get some input, thanks in advance Bighead.

hot_rod

Look into Wirsbo...

They have a light aluminum plate that is ideal for what you're talking about. The GC makes sleepers out of 3/4" plywood, and you place the sleepers below the wings of these plates and snap your 1/2" tubing into the grooves. Then he covers the whole assembly with plywood and VIOLA, dry sandwich radiant floor heating system. Just make sure you have some kind of insulation below this assembly or it may not work up to your and his expectations.

How's life on the western slope?

ME

frank s

Do it like this....

I just did a job with 1/2" pex 12" on center used 1x12's fot the sleepers then put downthe plates and laid the tube works like a charm here's a pic. The system was designed with the help of my friend Chris Maderia from Thames Valley Winnelson supply. Great guy very knowledgeable. Hope this helps,

Frank

Bob_9

Radiant panels

I would say to contact Stadler-Viega and see about using their plywood panel system. I've used it a bunch in all types of applications, works great, easy to install, has aluminum backer.

Frank_3

Wirsbo sells the Stadler-Viega panels under their own name as well. Same exact product, but sold as Wirsbo. There are some other above-the-floor dry radiant panel products available that have been talked about here. RTI and Rehau are two of the manufacturers that come up often.

tombig

3/4 pour

tombig

3/4\" pour

Well, guys. 3/4 " overpour on 1/2 or 3/8 pex? What about it? For that matter, what about 1/2 or 3/8 in a tile mortar bed, ceramic or stone? My gut feeling says no prob. but max. temps must be an issue. Control?

Bob Bona_4

I

was taught at the Wirsbo factory that the pour over PEX is 3/4 minimum. Not so much a control issue, but a transfer issue.

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Bigheadtodd

Thanks Guys


Thanks for the thoughts. I should have included in my first post that we had quoted a price for the plates, and the GC felt it was to high.

I think the problem I have is that the home owners really cant't afford to do the radiant and I should try to talk them into something they can afford to do correctly.

I have considered this as a compromise. Poor 3/4 inch of Gypcreat. We use a lot of light weight concreate up here in the mountains and I felt that the skinny slab would crack and create little sharp edges that would compromise the tube over time.

Maybe I can talk them into some real nice radiators or something.

Any how, thanks again.

Mark, you asked how things were going on the Western Slope. We are drying up. We need snow bad. It's as dry as it's been in 100 years.

Thanks again.

harvey

frankie,

Would you use 1x12's again or rip 3/4" plywood. Are those the thin aluminum(wirsbo) plates that you used? BTW I'm with you on your post about the mall. Harvey
P.S. What did you put over the sleepers(finished floor)?

kevin_5

If cost is an issue

is there any way you could do a staple-up job putting the tubing in the floor joists? Maybe I missed something, but I didn't see what type of floor you were working on. If it's a suspended floor with joists, that is a much more economical way to get the tubing in than either gyp-crete or the Wirsbo/Stadler plywood panels. Don't give up yet! Kevin

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Nate Perkins

Look at Watts black onyx. Their literature shows a sandwich system that should do the trick.

GH

Overpour The idea of using a cementious product is correct for
high performance of any system . Look at GCSradiant and
consider that you do not have to cover this product with wood
and you can for ever find your tubes for future changes.
Just screw the product down and cover with your finish floor. ALL DONE

frank s

Harvey

I would use the 1x12's again,less time consuming, On each end where the tubing looped around I cut a radius, it worked out really well. unless I was properly set up to rip down plywood in a proffessional manner, the reason I would opt for the plywood is that I don't feel it would be as succeptible to cupping, but then again neither should the pine in a properly conditioned environment, which is what I hope I created. Yes those are the thin Wirsbo plates, all else was supplied by Zurn. The finished floor was a laminate floor product (floating type)with a 1/8" foam pad underneath, it is working absolutely wonderful. Thanks for your support on the mall thing.
Frankie