View Full Version : 1/2" or 3/4" PEX in slab?

06-03-2010, 03:38 AM

I am planning the radiant slab installation in our new house in NH. Slab is approximately 1,500 sf.

I have to decide between 1/2" PEX spaced at 12" (5 rolls of 300ft) or 3/4" PEX spaced at 18" (2 rolls of 500ft). What do you think?



Doherty Plumbing
06-04-2010, 02:28 PM
I would suggest the 1/2" pex @ 300' coils with close spacing on the outside walls, especially near windows.

06-04-2010, 05:54 PM
Dan Holihan wrote a column about a friend of his who ran "1,000 feet of 3/8" tubing" for a system. The rest of the installation was a comedy of errors and he never told how it was resolved, assuming this was a factual recital of a system.

Wally Hays
06-04-2010, 06:53 PM
I strongly suggest that you have a proper load and design done. It will save you time, money and lots of aggravation.

10-27-2010, 02:23 PM
Wally knows of what he speaks. Hire the planning to be done by someone who knows more than you, and if you're feeling a little DIY-ish, you can follow the plans. United Leak Detection (http://www.unitedleak.com)