Looking for concrete/floor heat information

[slash007]

I am considering ripping out my concrete and putting in new floor heat at one location. I'm confused about what depth concrete I need to get quoted. I think the floor heat loops sit about 2" under the surface, but I'm told I need 6-8" of concrete. How would that work, and how deep would I actually need to remove from the old and pour new?

 

[cantbreak80]

We’ve always spec 4” of 4000+ psi concrete on compacted base.
We install 1/2” O2 barrier PEX over 3” foam insulation (Crete-Heat). The contractor must lower the finished grade to accommodate the new finished floor elevation.



Side note:
Concrete must have been really cheap in the late 70’s. This tear-out revealed upwards of 10” of concrete with black poly pipe directly on the dirt.
No wonder there were multiple cold spots.

 

[OurTown]

We’ve always spec 4” of 4000+ psi concrete on compacted base.
We install 1/2” O2 barrier PEX over 3” foam insulation (Crete-Heat). The contractor must lower the finished grade to accommodate the new finished floor elevation.
View attachment 9431


Side note:
Concrete must have been really cheap in the late 70’s. This tear-out revealed upwards of 10” of concrete with black poly pipe directly on the dirt.
No wonder there were multiple cold spots.
View attachment 9432 View attachment 9433

Have you ever replaced the floor on a wash with a monolithic slab foundation?

 

[cantbreak80]

Have you ever replaced the floor on a wash with a monolithic slab foundation?

Yes...with an uninsulated 4" overpour on top of the existing slab.

 

[slash007]

We’ve always spec 4” of 4000+ psi concrete on compacted base.
We install 1/2” O2 barrier PEX over 3” foam insulation (Crete-Heat). The contractor must lower the finished grade to accommodate the new finished floor elevation.
View attachment 9431


Side note:
Concrete must have been really cheap in the late 70’s. This tear-out revealed upwards of 10” of concrete with black poly pipe directly on the dirt.
No wonder there were multiple cold spots.
View attachment 9432 View attachment 9433

So you are pouring 4" of concrete on top of the foam insulation? Not sure what you mean exactly by "lower the finished grade to accommodate to the new finished floor elevation"?

 

[HeyVern]

So you are pouring 4" of concrete on top of the foam insulation? Not sure what you mean exactly by "lower the finished grade to accommodate to the new finished floor elevation"?

The dirt has to be 4" lower to accommodate the extra 4" of insulation so that the finished floor isn't 4" too high.