How Deep Should Pex Be Buried in Concrete?

• You can keep your floors warm with embedded pex tubing. Living Room image by Dawn from Fotolia.com

Shallow Is Good for Thermal Conductivity

• Pex is cross-linked polyethylene. It is a durable product that easily handles water up to 200 degrees Fahrenheit. This makes it perfect for floor heating. According to PEX Universe, your home's pex tubing lies on top of the steel reinforcing rebar set in the concrete. If the slab is 3 inches thick, this means the pex is at one inch below the surface. This allows the heat to rapidly diffuse to the floor surface.

Less Chance of Fracture if It Is Deeper

• You can bury your tubing as deep as 4 inches. This keeps the tubing safe from surface fracture and reduces the noise caused when the tubing expands and contracts with temperature change and rubs against the cement. It does, however, make for slow warm up times. In 2010, a sheath for the tubing that reduces noise is available.

Bottom Line

• According to Ed Boyea of Boyea Construction in Malone, New York, by placing the pex 2 inches deep in concrete you are getting a good combination of safety and good thermal conductivity.