radiant floor heating

[dug]

Has anyone heard of, or done radiant heating in a post and pier design home. I know they are usually done in slab foundations but I heard it can be used in standard joist construction and work very well. Thoughts?

[John Raabe]

You can do radiant heating in a lightweight slab poured on a standard joist floor. If you upsize the joists you can use standard concrete for more heat storage. I would check locally to see if there are other issues to consider. You should not cover this floor with thick carpet and pad as it will cut the efficiency. The best insulation should be in the joist side to keep your heat headed upwards.

You are adding a bit of extra weight to the beams and posts but in good soil this should not be an issue and the loading is well within the safety factor.

[dug]

Well I hadn't thought of that. The guy I was talking to said you could run the tubing between the joists, under subfloor, with insulation below. Maybe he was just blowing smoke, cause I had not heard of that before. Sounded interesting- if possible though.

[ScottA]

We tried the through the joist method you mention back in the mid 90's and it was a failure. Every house we did that way had complaints. The tubing needs to be in concrete as John mentioned. The concrete only needs to be 1 1/2" thick though. We tacked the tubing to the subfloor in a coil pattern and then they poured concrete over it.

[dug]

Good to know. Guess I'll go with my original plan and just heat with wood (I've plenty around). KISS- keep telling myself that. I've been in homes with floor radiant heat and it is soooo cozy!

[Squirl]

I have also seen a show with it in specially made 1" thick foam forms over the subfloor.  The tube was exposed on top with the form underneath.  It was then tiled or covered with hard wood flooring.

It was similar to this.
http://www.treehugger.com/files/2007/07/floor_panel_int.php

[dug]

Thanks Squirl- that seems like a slick system. Sounds pricy though, I will look into it.

[Squirl]

It probably wouldn't be difficult to router out 1# thick foam for tubing yourself.  Radiant floor heating can be an expensive installation almost anyway you cut it.

[MaineRhino]

I found that simply insulating the floor while heating with wood is quite toasty!

[firefox]

There is a separate sub forum in the link below that discusses radiant systems. I believe they have a system that doesn't involve a slab. There is a lot of  stuff there, most of the people are honest, but not all the players are honest, so
double check stuff.
Bruce

http://www.greenbuildingtalk.com/

[MountainDon]

I found that simply insulating the floor while heating with wood is quite toasty!

After we get the cabin warmed up, even the cold tile floor is not so cold. Stocking feet okay.   

[dug]

Thanks firefox, I'll check out the link. I will probably stick with my original plan and heat with wood at this point. I already have a nice stove and money is kind of tight. I am intrigued by the idea though and may try to figure out a way to do it later. I know it would make more sense to do it from the start but I like to make things difficult.

[firefox]

And I thought I was the only one who did that...

Bruce