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Radiant floor

Terry
Terry Member Posts: 186
Had a old Iron Pipe snowmelt system that developed leaks. Luckily there was a manifold c/w access on BOTH sides of the ramp. We disconnected each wrung from the header. Inserted 5/8" Kitec Pipe into each wrung & added the proper adaptors to the manifold, hooked up the Kitec, fired it up, & hoped for the best...

we were prepared to dig it up & do it right, but the owner wanted to try this option out first with no guarantee..

and what do ya know... it worked great!! still working after 6 years...

Regards
Terry

Comments

  • Wayco Wayne
    Wayco Wayne Member Posts: 615
    Radiant floor

    in an existing sunroom. I want to put down 1/2 plywood and then staple 3/8 pex to it, and then pur several inches of concrete over it all. The existing floor is concrete but not on grade. It had a small room under it that opens into the basement. Heat could run sown the walls to footings though. I was thinking the plywood would give a little insulation value to make the thermal mass smaller. Are there any problems with doing this? Would pressure treated plywood be better. Have plenty of room to add concrte because sunroom is a step down and doesn't need to be. Thanks for any input. WW.

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  • Dan Peel
    Dan Peel Member Posts: 431
    Why not...

    The plywood won't do much. If you're coming up the full 7 or 8 inches the old slab could be covered with 2" of sand then your 1 1/2 or 2" of rigid polystrene and still have loads of concrete. Dan

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  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,479
    Thanks for the reply

    We are limited by the outside wall as far as the height of the slab. Do you think that I should put down some R-max before the plywood. How thick should the slab on top be with the 3/8 tubing?? With R-max and plywood and 2 inch of concrete we would be able to get by with 3 inches of rise. The carpenter is replacing a sliding glass door and elevating the new one.

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  • Frank_3
    Frank_3 Member Posts: 112
    Radiant panels

    Why not use radiant panels from Stadler-Viega, Wirsbo, RTI, Rehau, or anybody else that makes them?

    What I think would work is a sheet of aluminum-backed vapor barrier, either from TekFoil or DennyFoil. Top that with a layer of 1/4 inch cork underlayment (R 2.6). Top that with the Stadler-Viega/Wirsbo radiant panel (1/2 thick) secured to the cement floor. You've got the downward heat loss handled by the cork and aluminum barrier and the floor height is only 3/4 inch high.

    (The reason I suggest the cork underlayment is to create a rigid surface that creates an air-filled gap between the panel and the aluminum vapor barrier. It will allow the aluminum to do a better job of reflecting heat back. If you just use one of the foil-bubble-foil reflective insulations I'd be concerned about the surface getting uneven over time.)

    As for the pressure-treated my thinking is that you'd want to avoid heating up all that CCA (chromium, copper & arsenic). In my book that's an abbreviation for Cancer Causing Agent. :-)
  • hot_rod
    hot_rod Member Posts: 22,018
    1-1/2 times the aggerate

    over the top of the tube. Generally 2" is spec. A bit smaller if you use pea gravel. Although not as strong as larger aggerate.

    I'd skip the plywood also. Tough to keep down flat without a bunch of "shots." compared to foam, and lesser R value. Foam staples or screw to keep PAP down, to foamboard.

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Craig Hovey
    Craig Hovey Member Posts: 1
    Leaking radiant floor

    Has anyone had any luck in sealing an old radiant floor system with iron pipe that has developed a leak ? I was hoping that there might be a sealer, pipe lining solution that might work instead of ripping up concrete. Locating the leak is some what of a problem because of the carpet covering the floor.
  • No such luck...

    there are internal lining systems available, but are applicable to straight pipes (water services) only.

    Sorry...

    ME
  • Steve Bergerson
    Steve Bergerson Member Posts: 38
    Why not use foam?

    Why don't you lay down 1"-2" foam panels, staple your pex tubing directly to the foam with foam staples and do a concrete overpour on top of that?

    Wirsbo, says that you can use 1", but if you can go thicker... it would be better.
  • Art Pittaway
    Art Pittaway Member Posts: 230
    Forget the plywood

    Steve and HR are right on target about the foam. 2" Extruded polystyrene and a box of foam staples works super. When your laying it out staple the bends and corners first, then if you have to make a change to the pattern pull a couple of staples and reset it. I like to see a minimum of 3" of concrete, less than that doesn't give you much between the tube and floor surface. Have you thought about anticipating heat rise in the room in the morning? Does it face South or E. W. ? If you use a thermostat, will heat from another room affect it? Just a few thoughts.
    Art
  • Joh n Brickey
    Joh n Brickey Member Posts: 43


    Why don't you lay 2x4's flat and staple the tubing to those and put 3/4" plywood floor over the top of it.
  • Straight shots...

    are doable, but pushing ANYONES tube around a corner is tough to do at best. Kinda like trying to put earth worms back in their hole, which reminds me of a joke...Got hairspray???

    ME
This discussion has been closed.