On Mar 12, 10:55 pm, "Jimi" wrote:
Hello,

I have bought a garage package (24ft x 30 ft) and plan on putting " in
floor" heat in the concrete pad. I have googled and done several searches
looking for a photo or any hand drawn examples of how to lay the pex pipe
prior to pouring the concrete. I would like to know how to determine the
diameter of pipe to lay...how far apart to lay the pipes ...how many grids
are needed?. This is a simple heated garage...very basic, but can't find any
schematic for laying this pipe....Thanks for any help on this... Jim

Hey Jimi,

I doubt you'll find anything online as each job is typically unique.
I can tell you from practical experience, it's the most forgiving
exercise in building you'll probably experience. Notice I didn't say
easy, or sloppy.

In a garage, I'd insulate the inside and outside of the footings, and
under the slab with 2.5 inch dense foam, blue or pink...but make sure
it's the dense stuff, I think I paid about $20 per sheet for the
Formular 250. The number of grids depends on the size of your
project, the size of pipe depends on the distance you'll be going from
your heat source. In the basement of the house I used all 1/2" pipe,
there isn't a run that's over 300' So one room has 5 runs with one
zone, another room has 1 run with 1 zone. On the 1/2 inch pipe,
where you make the 90 out of the concrete, sleeve the tube in 3/4
electrical PVC elbows, makes a nice smooth straight transtion.

In the above grade application, the first 3 rows of tube should be
about 6 inches on center beginning 6" exterior of the wall, from there
in spaced every 14-16". One place that was +- 50 to a workshop, it
uses 3/4".

You might want to check out these guys: http://www.pexsupply.com/
they have a ton of informaiton and supplies. Here's a picture of the
house I'm building with a picture of the basement floor just before
pour. http://goblin1.zool.iastate.edu/~dar...deas/Building/
photoalbum/target22.html You'll notice in the center all pipes come
together and are attached to the manifolds. By the way, make sure you
fasten the pipe securely to the insulation...of not, it could float
during the pour. I used staples which are a PITA. Some like to fill
the system with water, I didn't, but did have a full head of air on
the system with a pressure guage, so I could tell if one of the pipes
got nicked during the pour.

Bottom line is you should get some assistance if this is your first
project....either from the site provided, or from where you purchase
your supplies. It is a DIY project...but easier to do it right than
over.

DAC