radiant heat question in slab

[JimMorrissey]

I did the same thing with fiberglass, but I used the wire mesh just to hold down the PEX with zip ties. It was pretty easy the whole process actually. The only think I would do different is use a tighter spacing on the tube. I went 12", and I'd make that tighter to 9" or even 6". I could feel the cooler spaces through my sox on the finished (polished) concrete floor. If this is not a concern then 12" is OK. I didn't want to mess around with multiple zones so the whole lower slab was one zone. Radiant wants to be nice and even heat. We only have three thermostats on 3000 SQF.

 

[JimMorrissey]

I did the same thing with fiberglass, but I used the wire mesh just to hold down the PEX with zip ties. It was pretty easy the whole process actually. The only think I would do different is use a tighter spacing on the tube. I went 12", and I'd make that tighter to 9" or even 6". I could feel the cooler spaces through my sox on the finished (polished) concrete floor. If this is not a concern then 12" is OK. I didn't want to mess around with multiple zones so the whole lower slab was one zone. Radiant wants to be nice and even heat. We only have three thermostats on 3000 SQF.

 

[Doc_Bob]

</font><font color="blue" class="small">( I did the same thing with fiberglass, but I used the wire mesh just to hold down the PEX with zip ties. It was pretty easy the whole process actually. The only think I would do different is use a tighter spacing on the tube. I went 12", and I'd make that tighter to 9" or even 6". I could feel the cooler spaces through my sox on the finished (polished) concrete floor. If this is not a concern then 12" is OK. I didn't want to mess around with multiple zones so the whole lower slab was one zone. Radiant wants to be nice and even heat. We only have three thermostats on 3000 SQF. )</font>

I did the same as you, fiber mesh in the concrete, wire mesh with tubing spaced 12" apart held down with zip ties. I did not put wire over the tubing. Not needed.
Bob

 

[Doc_Bob]

</font><font color="blue" class="small">( I did the same thing with fiberglass, but I used the wire mesh just to hold down the PEX with zip ties. It was pretty easy the whole process actually. The only think I would do different is use a tighter spacing on the tube. I went 12", and I'd make that tighter to 9" or even 6". I could feel the cooler spaces through my sox on the finished (polished) concrete floor. If this is not a concern then 12" is OK. I didn't want to mess around with multiple zones so the whole lower slab was one zone. Radiant wants to be nice and even heat. We only have three thermostats on 3000 SQF. )</font>

I did the same as you, fiber mesh in the concrete, wire mesh with tubing spaced 12" apart held down with zip ties. I did not put wire over the tubing. Not needed.
Bob

 

[bg71361]

Here is a shot of tubing tied to wire mesh.
Bill

 

[bg71361]

Here is a shot of tubing tied to wire mesh.
Bill

 

[bg71361]

</font><font color="blue" class="small">( Hey, I recognize your name now....
You're the person I replied to that was building a kennel and never posted again. You were going to take pics or something... )</font>

Looks like she struck again! /forums/images/graemlins/confused.gif

 

[bg71361]

</font><font color="blue" class="small">( Hey, I recognize your name now....
You're the person I replied to that was building a kennel and never posted again. You were going to take pics or something... )</font>

Looks like she struck again! /forums/images/graemlins/confused.gif

 

[Freds]

You may be right.
I remember someone posting a couple years ago.... or maybe it was last week /forums/images/graemlins/crazy.gif, about how people will get a bunch of replies, but you never hear back if they took the advice or the way they tried to do it worked ok....
It's nice to get a back and forth feedback going, rather than just back, or maybe I mean forth /forums/images/graemlins/grin.gif, so we can all learn.

Oh well.

 

[Freds]

You may be right.
I remember someone posting a couple years ago.... or maybe it was last week /forums/images/graemlins/crazy.gif, about how people will get a bunch of replies, but you never hear back if they took the advice or the way they tried to do it worked ok....
It's nice to get a back and forth feedback going, rather than just back, or maybe I mean forth /forums/images/graemlins/grin.gif, so we can all learn.

Oh well.

 

[DMF]

</font><font color="blue" class="small">( <font color="red">I read not to put near toilet, the heat will melt the wax donut</font>

Fernco now makes a rubber gasket that glues to the toilet bottom & is a snug fit into the toilet flange eliminating the wax ring. made specifically for heated floors. Found it at Home Depot with the wax rings. I'll never use a wax ring again. )</font>

While I might agree that the rubber gasket may be better than the wax ring, I really don't think the floor will melt it. I have radiant heat in every room except our carpetted bedrooms (3) and the loft. My basement has it as well. Our 2 bathrooms have wax rings with no problems. The floors in those bathrooms are tile. They are never "hot"; they just don't feel cold to the touch so they have to be around +/- body temperature. I'm thinking if you hold a wax ring in your hand it wouldn't melt so it probably isn't as much of an issue as some people might think... Just my $.02...

For the basement we used one sheet of mesh, 6 x 6 with the tubing tied to it. When the cement was poured, we "hooked" the mesh to pull it up into the cement. It works good! Counting our basement, we heat over 3700 square feet and we average a little under 100 gallons of oil/month. My wife keeps the house at 72 degrees all winter and the oil heats our water as well. Many new homes in our area use that much oil and heat a significant amout less of square footage...

 

[DMF]

</font><font color="blue" class="small">( <font color="red">I read not to put near toilet, the heat will melt the wax donut</font>

Fernco now makes a rubber gasket that glues to the toilet bottom & is a snug fit into the toilet flange eliminating the wax ring. made specifically for heated floors. Found it at Home Depot with the wax rings. I'll never use a wax ring again. )</font>

While I might agree that the rubber gasket may be better than the wax ring, I really don't think the floor will melt it. I have radiant heat in every room except our carpetted bedrooms (3) and the loft. My basement has it as well. Our 2 bathrooms have wax rings with no problems. The floors in those bathrooms are tile. They are never "hot"; they just don't feel cold to the touch so they have to be around +/- body temperature. I'm thinking if you hold a wax ring in your hand it wouldn't melt so it probably isn't as much of an issue as some people might think... Just my $.02...

For the basement we used one sheet of mesh, 6 x 6 with the tubing tied to it. When the cement was poured, we "hooked" the mesh to pull it up into the cement. It works good! Counting our basement, we heat over 3700 square feet and we average a little under 100 gallons of oil/month. My wife keeps the house at 72 degrees all winter and the oil heats our water as well. Many new homes in our area use that much oil and heat a significant amout less of square footage...

 

[RichNJKubota]

I put radiant heat in the garage. It was assembled in the following layers.
1. 4" 3/4" stone
2. Vapor barrier
3. 2" rigid insulation taped together
4. Vapor barrier
5. Wire mesh
6. 2 loops PEX tubing zip tied to wire mesh
7. Wire mesh with zip ties to the first wire mesh

The concrete has yet to crack after almost 10 years and there are no moisture issues.

 

[RichNJKubota]

I put radiant heat in the garage. It was assembled in the following layers.
1. 4" 3/4" stone
2. Vapor barrier
3. 2" rigid insulation taped together
4. Vapor barrier
5. Wire mesh
6. 2 loops PEX tubing zip tied to wire mesh
7. Wire mesh with zip ties to the first wire mesh

The concrete has yet to crack after almost 10 years and there are no moisture issues.

 

[bebster]

Looks like a good system, except I agree with the comment on the bricks. I have purchased concrete bricks and broken in 1/2 and used them to prop up the rebar -- these bricks are the same size as standard clay bricks just poured out of concrete.

I don't like the wire mesh (nor does my slab contractor) since it gets stepped on when the concrete is being worked on.

An alternative that is easier is to use 3/8" (#3) rebar 18" on center in a mesh pattern and just use 7" plastic zip ties to tie it off. I find that if I use 1/2" pex and run it along side the rebar that I get just about the right amount of BTU transfer for the application. To get enough concrete coverage, you'll need to plan on at least a 5" thick slab (so that you get 2" below and above the rebar/tubing system). But you'll have a strong slab that you can park a tractor on top of.

 

[bebster]

Looks like a good system, except I agree with the comment on the bricks. I have purchased concrete bricks and broken in 1/2 and used them to prop up the rebar -- these bricks are the same size as standard clay bricks just poured out of concrete.

I don't like the wire mesh (nor does my slab contractor) since it gets stepped on when the concrete is being worked on.

An alternative that is easier is to use 3/8" (#3) rebar 18" on center in a mesh pattern and just use 7" plastic zip ties to tie it off. I find that if I use 1/2" pex and run it along side the rebar that I get just about the right amount of BTU transfer for the application. To get enough concrete coverage, you'll need to plan on at least a 5" thick slab (so that you get 2" below and above the rebar/tubing system). But you'll have a strong slab that you can park a tractor on top of.