heated floors.....

casey in SD

Oxygen-barrier PEX is the only way to go. I think it runs about 40 cents a foot in 1/2" ID. Which translates to 40 cents per square foot of floor.

casey

Sorry if I was a little harsh, but I went through the same thought process myself with my shop. I wanted to have the option of heating it later, but I didn't want to shell out any more money than necessary. I came to the conclusion that when you consider the whole project, the cost of PEX is not that much.

If you're not sure that you're going to heat it, you could go with a non-O2 barrier PEX. However, you would need to use a bronze pump, so you wouldn't be saving any money on a small shop or garage.

You do need to insulate your floor for radiant heat, but there are ways to save money on insulation. Here are some options:

1. (Best) 2 inch high-density foam around the perimeter and under the slab.

2. (OK) 2 inch high-density foam around the perimeter and the outer 2 or 4 feet of the slab. Use 1 inch high density foam under the rest of the slab. (That's what I did.)

3. (OK) 2 inch foam around the perimeter, but go down at least 2 feet below grade.

4. (Not OK) No insulation.

If you choose option 3, you'll save quite a bit on a large building without losing too much heat. Whatever you do, make sure you have some insulation around the floor.

I got my PEX from MV Supply. See link below. Their "rough-in" packs are a fairly good deal.

• MV Supply

I did a considerable amount of research on in floor heating and I would not even consider anything else. There are too many horror stories of leaking in floor heating.

By the way, whatever you put in, you need to be EXTREMELY careful not to crimp the tubing during installation.

Good luck,

Cliff (VA)

Using pipe without an oxyen barrier allows atmospheric oxygen to migrate into the hydronic fluid, causing rusting of iron and steel components in your boiler and plumbing.

The correct stuff is not all that expensive, and installing it under a slab is a one-shot deal... you want to get it right the first time.

Do a Google search for cross-linked polyethylene.

I would check the pressure rating of your plastic hose. Contact the manufacturer of the product. Sometimes the pressure rating is for Cold water, and, sometimes, some heating service persons put "anti-freeze" in the boiler. Hydronic pipe (plastic) can be "tricky".

Hope this helps. John,PA