PEX Tubing in Slab on Grade

[jjeng2]

I have a slab on grade that has been designed as 6" per the ACI/PCA method for point and distributed loading. The client wants an alterante which will include a heat/snowmelt system which will consist of PEX tubing at 8" c/c. Are there any ACI references to account for this within the structural slab? What if I pour 6" of structural slab and embed the tubing in a few additional inches of concrete under the 6"? Does this then become my "subgrade"? Any thoughts, references, or experience would be appreciated.

 

[Bagman2524]

What size is the tubing? The extra slab depth sounds reasonable. You might just want to add whatever the diameter of the tubing is to the depth of the slab to give your required 6". I wouldn't consider the extra depth as subgrade.