Radiant Floor Insulation questions

[pearltsi]

Ok, So i had a pole barn 30x60 built. I had wait until i saved up enough to concrete and heat it. I want to put radiant flooring down in the slab. I will be having a larger 25k# truck in the shop occasionally, So i figured a 6" concrete.

My questions are.

1. I am looking at the insulation for under the slab. I was going to buy 2" board from a local supplier NEW. But i found some used stuff which looks perfect. 2.75 inches thick. R factor is 5 per inch. Its over 25psi. XPS Would this ok for under the slab. I tried to find information on this type of setup but it real hard to find.

2.When I do insulate under the floor what do I do with the garage doors where the concrete would flow into the driveway. I know you go around the slab inside but i dont want a chunk of insulation visible.

Any input would be appreciated.

And pics for reference.

 

[Sureshot]

I don't think you run the insulation in front of the door. On the inside you can run the insulation between the posts.

I don't know anything about the insulation you are looking at. I did the same as you and had to wait on the floor for a year. At the time nothing was mentioned of underslab insulation so mine is on the dirt.

 

[dcs Inc]

Radiant floor heat radiates heat in all directions. The more insulation under the slab the more efficient the system. The last one I installed I placed 2 sheets of 4" rigid foam insulation and poured a 6" slab over it. This was a hot water system with a boiler. I've been talking to a buddy of mine that uses our overlay systems and he spray foams subgrades for concrete placement with that are installing radiant systems. I thought that a great idea. Electrical systems can be a major money drain if not insulated real well. You can find the heat loss indicators online concerning insulation values.

 

[S141995]

When I did my radiant flooring I used a new product made in Granby Quebec. Here in quebec radiant fllooring gets more popular. It's called hydrofoam made by polyform.

http://www.polyform.com/images/pages/image1.jpg

http://www.polyform.com/pages.php?page=insulation_products#

http://www.polyform.com/pages.php?page=insulation_products#

Install is very easy, 2.5 in is rated R10 what is enough for our weather condition in Quebec.

What I suggest is to use 1 inch of gravel ( crusched stone , or dust stone) and level it before installation. Took me only 1 hour to install the pex tubing what was fantastic !
Price is around 40$ for a 4-5$ sqaure feet, it's twice the price of regular insulation but such a time saver !