Hydro foam users and pex depth

[Pitbully]

Good morning,
I’m very slowly completing a garage build. A long time ago I bought hydro foam 3 3/8” but after reading a lot of information - maybe I shouldn’t have. With pex needing to be around 2” depth I don’t know if 2” of concrete over the pucks is enough to support a heavy car or 5th wheel. For those that did go deeper any regrets?

 

[Firebrick43]

Good morning,
I’m very slowly completing a garage build. A long time ago I bought hydro foam 3 3/8” but after reading a lot of information - maybe I shouldn’t have. With pex needing to be around 2” depth I don’t know if 2” of concrete over the pucks is enough to support a heavy car or 5th wheel. For those that did go deeper any regrets?

First, PEX doesnt need to be at 2" depth, it need to be at least 2" but that is if its tied to wire mesh or something to float in in the center of a slab. It can be on the bottom, heat rises and the foam reflects what does go down back up. Is your version of hydrofoam hold the pex up somehow? Or are the pucks height the diameter of the pipe?

Also with standard concrete 4" depth is the standard. One might get away with a 3" slab but even that is risky if not engineered correctly

 

[Pitbully]

Mine holds them I believe it’s 1” below. Funny the different facts you read on the internet. I’m in Ottawa Canada and was going to pour 4-6” as I have the opportunity to park a 5th wheel or motorhome on one side. I’ll post photos in a bit.

 

[mike93lx]

Mine holds them I believe it’s 1” below. Funny the different facts you read on the internet. I’m in Ottawa Canada and was going to pour 4-6” as I have the opportunity to park a 5th wheel or motorhome on one side. I’ll post photos in a bit.

Your 5th wheel doesn't need 6" of concrete. Ground pressure is far less than most would think

Base prep matters the most anyway

 

[Pitbully]

 

[Firebrick43]

So with those board the pex is setting on the bottom of the concrete and it appears to be a full 4" plus. Looks fine to me.

 

[Pitbully]

I am building over an old garage hence why it has taken me quite some time. I couldn’t just tear the structure down I had to build overtop of it. Already existing concrete was reading vapour barrier then foam then concrete. Total would be 4-6” concrete then poly then foam then 3-6” concrete more as you can see it wasn’t poured evenly.

 

[Pitbully]

So with those board the pex is setting on the bottom of the concrete and it appears to be a full 4" plus. Looks fine to me.

The last pic is with no foam I have 1” foam board too the other board is xps I put down so my cars wouldn’t bottom out lol

 

[Pitbully]

Figured I would post my cars

 

[jack stand]

It can be on the bottom, heat rises and the foam reflects what does go down back up.

Heat seeks cold but hot air rises.
That's one of the great benefits of radiant. Radiant like the sun's heat vs your ducted hot air rising to the ceiling.
This is also the reason to insulate very well under the radiant tubes so that the heat is drawn or directed towards the living space, remember heat is seeking cold. I've never used the "hydro foam" as any of it that I've seen is the "coffee cup" type foam with the lowest r value per inch of all of the foams. Although it sure looks like it makes placing the pex a breeze!