Creatherm panels

SWEI

Anyone have experience with these for slab-on-grade residential?  I have a client who wants to use them but I'm a bit concerned about the tubing being so close to the bottom of the slab.



thanks

Zman

Too low

I agree that they hold the tubing too low. It will increase downward heat loss and force you to run higher temps. I realize you already know this.

The only way I have been able to get the tubing at the correct height is by using a rebar grid and putting it on chairs. I think tying it to the mesh is ineffective both structurally and from a from a heating point of view. Unless you personally supervise the pour, the tubes will end up at the bottom. Even if you do oversee it, it is a guessing game and you won't make any friends in the concrete world.

Carl

SWEI

Tied to rebar

is what we've always done.  Rebar always on chairs -- regardless of whether there is RFH in the slab or not.



Thanks for confirming my suspicions.

zacmobile

pipe depth

I've been curious about the Creatherm panels for quite a while, I notice they use similar panels almost exclusively in Europe for radiant floor installations. I do agree though it's better to have a bit of space under the pipe for more efficient heat transfer but I think rebar or mesh should be the uppermost component to limit surface cracking. My typical radiant floor I install goes from the bottom up: vapour barrier > styrofoam > pipe tracking > pipe > mesh. Usually the mesh sits right on top of the pipe witch gives it a good position in the slab & the tracking give the space between the styro & pipe. I think rebar is overkill for anything but a garage.

Dent

Radiant panels

Take a look at wwwradiantgreenflooring.com they have a panel that is similar but less expensive and is a eps foam with 2 inches below pipe.

Zman

Same

Dent,

The goal is to get the tubing centered in the slab.

This product has the same problem. The tubes are at the bottom of the slab.

Carl

Dent

Eps foam

The Eps foam that is used in these radiant panels is no different then the white foam coffee cups are made of(expanded polysteren foam, (eps) think of it this way, coffee in the cup at around 135 degrees doent burn your hand. The heat only goes up. No loss of heat goes downward, and the r-value is much less in a thin foam cup

Zman

Really?

Dent,

I assume you work for the manufacture?

I wasn't originally questioning the r-value. Now that you mention it, I don't see an EIS report on the web site and I see words like "average r-value". It is less under the tubing, yes? Is the report available? It also seems that the tubing is not fully encased in concrete. It is touching the foam on the bottom and most of the way around at the turns.

See the attached article from an industry great.

The depth does matter.

Carl

SWEI

Polystyrene Foam

EPS and XPS are made from the same resin and have similar R-value, but are structurally quite different.  XPS is stronger and costs more.  I have never seen EPS used under a slab.