Advance input needed on radiant

[Overboost44]

I titled this the way I did because I have not begun my project. I have not started a build thread...yet.

While I am awaiting drawings, I am thinking and planning ahead. I will be the GC on my long-awaited 32x26 attached garage project. I have done a ton of research and this site has been invaluable for information. Now I am concentrating on getting the radiant heat system laid out. Foundation and footers will be done by others. I will likely lay the rebar in all areas and plate tamp the stone. I will be installing the radiant tubing and tie it off to the rebar. The slab will be 5" 4000psi, and rebar will sit on 2.5" chairs. This will all sit on a 10 or 15mil vapor barrier and 2" R-10 insulation on bottom and sides.

The design options seem endless and I can always get a supplier to send me a loopCAD or do one myself. Again, just thinking ahead and looking for opinions. So, 832 sq. ft turns into about 775. I will need 3-300' rolls or a 1000' roll if I want to keep some long lengths for another project. Here is my drawing. Circuit 3 (at the top) could be layed out like the 1st and 2nd or vice-versa. You will see the lift location and the possible support pole location for the 14' wide second story. I will avoid each of these areas with the tubing and have plenty of pictures/video to be able to verify. I have estimated the lengths of each circuit at 251', 251' and 269'

Here is my rendering. I look forward to your thoughts.

 

[TurnipTruck]

I would staple the pex to the foam and then place the mesh on chairs.
Don‘t be afraid to keep the pex a couple feet away from the hoist posts.
No pex under the walls or outside the overhead doors.
Don’t kink the pex!

 

[Overboost44]

I would staple the pex to the foam and then place the mesh on chairs.
Don‘t be afraid to keep the pex a couple feet away from the hoist posts.
No pex under the walls or outside the overhead doors.
Don’t kink the pex!

Thanks. Why on the foam as opposed to strapping to the rebar? I was thinking that higher in the concrete would be better. The other two points are noted and will not be under the walls or outside the doors.

 

[TurnipTruck]

I murdered my back hunching over for a full day tying tubes to the remesh on my first slab. Now you can stand up to staple tubes to the foam in any pattern or spacing you like, like near together at the perimeter and spaced farther apart midfield, or avoiding the two-post anchoring, or bulbous 180s with radii greater than the center to center distances.

 

[Overboost44]

I guess there are no other opinions. I may not have searched well, but I can't find a lot of info on design options.

 

[dscheidt]

I guess there are no other opinions. I may not have searched well, but I can't find a lot of info on design options.

Where the tubes are in a properly built slab does not matter a whole lot to the performance of the heating, because the concrete is going to come to temperature before much heat is transferred into the space. Stapling to the foam is faster than tying to rebar, and doing it that way means the heating contractor can put the foam down, install the tubes, and brr er out of way of the concrete crew.

Pressurize the tubes, so it’s immediately obvious if someone puts a hole in it.

 

[Overboost44]

Where the tubes are in a properly built slab does not matter a whole lot to the performance of the heating, because the concrete is going to come to temperature before much heat is transferred into the space. Stapling to the foam is faster than tying to rebar, and doing it that way means the heating contractor can put the foam down, install the tubes, and brr er out of way of the concrete crew.

Pressurize the tubes, so it’s immediately obvious if someone puts a hole in it.

Excellent. So as long as the OA lengths remain close, I should be fine no matter which direction I lay it. I will be doing the foam, rebar and pex. Good tip on pressurizing immediately so I can be certain of any punctures. Appreciate you both.

 

[TurnipTruck]

I like the beginning of the loops (hotter water) to start on the perimeter of the slab and work their way inward.

 

[Overboost44]

I like the beginning of the loops (hotter water) to start on the perimeter of the slab and work their way inward.

I agree with you there. That is somewhat taken into consideration in my drawing. Circuit one has the hottest water closest to the garage doors. Circuit 2 has the hottest water closest to the return of circuit 1. Circuit 3 (mostly just an option for illustration purposes) I considered the hottest water where I would be doing the most work. The left side is a parked car and there will be steps in the top left. Will work on another design as an option.