I have an old 14x22 garage, Id like replace the dirt floor with concrete this summer. Id like to include tubing and insulation for heating in the future. Anyone got any advice or resources as far as what tubing or insulation leaves me the most options down the road?
Don’t have a heat source . Wood boiler, solar , Lp ?? Foundation is old block . Sent from my iPhone using Tapatalk
Not knowing heat source, I would use an 1/2" oxygen barrier pex. The pexalpex is easier to use, but a little more expensive. Excavate down 10" below top of finished floor. Insulate block walls with 2" foam insulation. Place 4" of modified stone base and compact. Insulate floor with 2" of high density foam insulation. Place 6"x6" 2 gauge wire mesh mats on top of foam. Tie the pipe to the mats with zip ties at 12" on center. 14 x22 gets you to the max length pipe per zone- 300' Place 4" concrete 3500 psi and finish. That should get you started and will lead to multiple questions.
Thanks. I've put these in over the years and learned what works. It's not Rocket Surgery and there's a lot of info out there. Some guys make it more difficult than it has to be.
I think I recall reading that for far northern climates like OP, the foundation is supposed to be insulated a minimum of 24" down, and more is better...and more than 2" thick is recommended for out against the foundation too...
It's an old garage and I assume it's not being converted to a residential occupancy. More insulation is always better, but there's the cost benefit ratio to look at. I gave it my best shot with limited info. Hopefully OP does some homework.
If needed and problem always take a back hoe outside perimeter and lay 4x8 rigid on 4’ deep on perimeter. Hey I’ve had frost 6’ deep here
Should’ve done it 10 years ago before we needed insulated foundations to have a heated floor. It was warmer then, I guess
Foundation insulation has been part of the building code since I started reading those funny books in 85 and I've renovated buildings built in the 70's that had insulated foundations. The codes have changed a lot since BOCA 79 and code enforcement has become widespread.
Could be. Wasn’t until about 10 years ago that it was enforced here. Built many basements and crawlspaces that were damp -proofed and backfilled throughout the 90’s and 00’s. It’s still not “code” to need to do anything to a garage foundation to heat the floor.
My jurisdiction requires a minimum of R-15 underslab insulation in any space with heat, as well as continuous insulation on both the inside and outside of the foundation walls. It has to extend to the top of the footer, not just to frost depth. The goal is to eliminate thermal bridging. My place was built in 2005 and has continuous R-10 exterior and interior foundation insulation all the way to the footers. Most of the under-slab insulation I see these days is closed cell spray foam, then you don't need to worry about taping/sealing the joints in the rigid stuff. Many municipalities have local code adoptions that are more stringent than what you will find in the IRC, particularly when it comes to energy efficiency and deck construction. But yeah, 1/2" HePex (or similar) is what you want to use for your radiant tubing. Air it up to at least 100 PSI to leak test it. Finding out you have a leak after the slab is poured and cured will be a bad time.
That's a big 10-4! I keep the lines pressurized with gauge on it so I can monitor for days after the concrete is placed. Never had one leak, but can't be too careful.
