Radiant Floor Heat Insulation

[maxpower_454]

Ok so I ordered my kit from blue ridge and got the stapler as well. My pad should only be 4-5" thick so they said it really wouldn't make a difference whether I pulled it up or stapled it to the floor.

My questions are:

1- Has anyone on here who stapled the tubing to the foam had any problems when the floor cracked (either at joints or elsewhere) and are you happy with the heat? Anyone use 2 layers of 1" foam under the slab? It's actually cheaper for me to go that way. Will the staples still stick ok?

2- How deep in the ground should I put my insulation on the sides of the slab??I can go 7" below the slab pretty easily and that will make the pieces I need about 12" wide which works out perfect. Is this deep enough? Also how thick should it be on the sides? I'm planning on about 2-3" of foam. Is this about standard??

Thanks in advance

 

[wedge40]

I'll be interested in peoples reply about how far down to go on the sides.

If you think about the staples just hold the pex inplace till the cement is poured. My guess would be it would just go throught the top piece and into the bottom and hold just fine.

Will you be using any rebar or wire mesh? Also if you're only putting in 4" of concrete I'd want the pex as low as possible to make sure it's not cut when they cut the joints.

Wedge

 

[maxpower_454]

No rebar or mesh. Just using fibermesh concrete.

That's exactly why I'm stapling it to the foam. the last thing I need is to cut every piece of tubing the the saw!!

 

[maxpower_454]

Anybody else?

 

[BadgerBoilerMN]

Perimeter insulation is sized and installed to the frost line. Frost goes in, or down and the insulation should follow. In other words 2" of insulation running 4' in from the outside wall is better than 1" running down to the footing. If you have a floating slab this will hold true. If you have a footing wall, it must be protected by from frost.

Two layers will work but not ideal. Stagger and lap the sheets.

 

[maxspeed96ct]

No rebar or mesh. Just using fibermesh concrete.

That's exactly why I'm stapling it to the foam. the last thing I need is to cut every piece of tubing the the saw!!

You may still need rebar or mesh still to hold the foam down, I know I did .

Last thing you want is for it to float while the crete is poured .

 

[maxpower_454]

Why would it float if it's stapled down?

 

[gpalmer77]

No rebar or mesh. Just using fibermesh concrete.

That's exactly why I'm stapling it to the foam. the last thing I need is to cut every piece of tubing the the saw!!

My concrete guy is tooling the control joints in, not cutting. No chance of hitting the Pex. I am using The Barrier blanket type insulation instead of 2" foam board, so no need for leveling sand, and less excavation. Mesh, with pex attached, lifted during the pour to ~1-1 1/2' off the bottom, and rebar also. Rebar is cheap insurance against any minor cracks expanding. $300 on a $9k job (footing and slab) was an easy call.

 

[BadgerBoilerMN]

The Barrier blanket type insulation instead of 2" foam board Rebar is cheap insurance against any minor cracks expanding.

First, blankets are for beds, it should not be called insulation and is certainly inadequate where insulation is really needed under any radiant slab.

Second, rebar does not insure against cranks, nothing does. But will greatly
increase the "control" of the inevitable cracks you will have and adds strength where required by potential loads.

 

[joes169]

First, blankets are for beds, it should not be called insulation and is certainly inadequate where insulation is really needed under any radiant slab.

Agreed......

Second, rebar does not insure against cranks, nothing does. But will greatly
increase the "control" of the inevitable cracks you will have and adds strength where required by potential loads.

Pretty sure he stated that the rebar would keep cracks from "expanding", not eliminating them altogether, which is accurate...........