Another radiant question

Lou Miller

I posted before about a radiant system I want to install in a woodworking shop. I'm undecided on the type of flooring I want to use. What I'm leaning towards is: 2x10's with 3/4" OSB and r-30 insulation (area underneath is unheated) for the sub-floor. Stapling 1/2" pex to that. Instead of putting down some type of wetbed, I want to put down a layer of reflective foil, 2x3 sleepers (with notches for the pex everywhere) spaced 12" on center, and then nail down 3/4" hardwood flooring to the sleepers (making sure not to puncture any tubing of course). It may not be the best situation, but this should work fairly well, shouldn't it? I want a wood floor because of the comfort factor. It's a lot easier on the back to spend 8 hours on a wood floor than it is a slab. It's more expensive this way, but being out of work with back pain can be a lot more expensive.

I'd appreciate any thoughts on this method of installation.

Tom_38

Quick Trac


Lou have a look at the Wirsbo Quick Trac or Roth panels. You just install it on top of your osb board and snap in your tubing. then install your wood floor.***** make sure you have a max limit set for your water temp,as not to over heat your floor. Contact a contractor for more info.

Mike T., Swampeast MO

Or consider Warmboard

Heavy aluminum layer on top of the sub-floor.

It's completely structural, has VERY high heat transfer and you could put a reasonable rubber-based floor on top to ease the wear on the feet.

The thicker and more resilient the floor on top of the Warmboard, the more you need to consider the insulation below.

Lou Miller

I really like the idea of the warmboard. Any rough idea of what that stuff goes for? I'm guessing somewhere around 3-4 times the cost of OSB. I'll probably contact them in the morning. Unless the cost is absolutely ridiculous, that's what I'll end up with instead of my original plan. Thanks.

CLC

Above Floor Fin

Take a look at this product from Radiant Engineering. The U-Fin is designed to go on top of floor with sleepers between runs. The 4" wide by 8' long pieces allow universal layout design and superior heat transfer to floor surface. Pics illustrate a design using UFin 8" on center.

hr

The conduction transfer

that you get from Warmboard or the site built fin system is worth the time and money, imo.

If this is over a slab make sure you deal with any moisture issues if the fiberglass batts contact the concrete below.

If you chose to build your own, I'd look into the Radiant Engineering ThinFins. A lighter gauge, extruded aluminum transfer plate that would work fine in a sandwich method like that.

Also available from Watts Radiant in 8 foot lengths.

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Lou Miller

Thanks

Thanks for the info guys. I've got a few different ways of doing it now, but I really like the idea of the warmboard the best. I let you all know how it works out and probably post a pic or two when it's done. I'm breaking ground in two weeks, so I should be getting to the heat in about 6 weeks or so.

The floor is not over a slab. I'm actually going with a full 8' basement under the shop (35 x 60) that will be unheated. It's just for storage and it's almost completely underground, so it really shouldn't get that cold down there. I'm probably going to use TJI's for the floor joists and I'll put r-30 underneath the the sub-floor. R-26.4 on the walls and R-54 in the ceiling. With that much insulation, I might be able to get by with just a couple of candles and a small fan

Thanks again!

Weezbo

Louie .....Dont forget a vapor barrier on the ground under the

floor with tji's it really is a winner on well insulated homes . The Weezbo.*~/:)

hr

Gosh, if it is

a dry system on framing with room below... Warmboard would be a first choice then transfer plates from below a second. Both easy to install and perform closely to one another.

Even with 12" oc spacing on the WB, it really kicks out an even heat spread.

These pics show the most common below floor systems, staple up EPDM, suspended pex, ThermoFin, and Warmboard. Compare the WB to the ThermoFin 8" oc below Advantec 3/4" subfloor.

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Unknown

If you have a low heat load, you may not even need heavy gauge plates. put down your sleeper/infill, staple down some lightweight plates, fill with PEX-Al-PEX.

it's the cheapest non-concrete floor app, and it's got respectable output (better than quik trak, not as good as warmboard or extruded plates). It's a good DIY option if your loads aren't too high.

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