ok...you convinced me to get in floor heating

[Pulleye16]

Back to the garage...

Sounds like I'll be going the propane route. How I do that is still up for discussion, but it ultimately seems like the best route to go.

It also seems like I should go with in-floor heating.  The overall dimensions of the garage will be ~26x31 with my "heated shop" being ~12'x26'. I think I'll just run in floor heating throughout the whole garage. How many zones should I do? My buddy has a typical 3 stall garage all on one zone and he said it's not set-up correctly. He said the loop is too long and the water is basically cold by the time it comes back.

You think I could get by with two zones...one for the 12x26 and another for the 19x26? Do you guys recommend an "off-peak" electrical box? Gas or electric for in floor heating? Any issues if it sits unused for 5-10 years? I'm guessing I'll really want it when I retire but won't see much use now. Should I put it in when doing concrete?

Thanks...and if anyone knows a builder/concrete guy in the Siren/Webster area, shoot me their contact info. Hoping to tackle it this spring/early summer. 

[glenn57]

i'm by no means an expert on in-floor heat....but isnt always in the concrete????/

[mike89]

no it can placed on a current pad and then repoured on that I think, if I remember right...   

[LPS]

A guy I know has in floor heat in his shop and said he had lots of problems the first few years because he didn't add the additive that keeps it all good.  ???  He uses it now and says it works much better.

[Dotch]

Been over 15 years ago since ours was done but seems like the tubing was placed on top of the 2" thick pink foam sheeting to insulate the tubing from the soil and the concrete was poured on top of it. Don't see any reason why it couldn't be poured on top of an existing slab following the same procedure. Don't see why you couldn't get by with two zones although ours is all one zone in the attached 3 stall garage. It's ~40' x 30'. Don't see the problem your buddy mentions here but if you want to heat part and not the other part, you'll have to go separate zones. The lines are full of a water-antifreeze solution. Occasionally some water needs to be added so after a few years, it can become diluted somewhat. Haven't had any issues here, yet. Off peak? Ya, I'd look at it but I'd also check on LP. The boilers now vs. what we had to choose from are a lot more efficient and cost effective, especially when LP is cheap. Some of the electric companies get stinky about that. They want you locked into their system and frown on it if you're switching back & forth. May pull your off-peak status I've been told. 

[Scenic]

Floor heat is great in some respects.  If you are putting in a new floor this would be the time to run the lines for your use later.  When we built our shop we chose to put the money in insulation instead. We put insulation under the concrete and our floor is never cold even in these temps

 Just a couple pros and cons:

Pro: Floor is never cold
       Holds heat for a long time
       
Cons:  COST of the system.  Nothing cheap about floor heat.
           If you want to warm a building up Fast there is nothing fast about floor heat
           Humidity as stuff melts off your vehicles it causes humidity in the air
           No fans blowing dust around
           

[Cooperman]

Pulleye, I have infloor heat in both the house and garage (2 car) oversized with one garage zone. But if I had a shop I would 2 zone it, one for the shop, and one for the garage area. I have a natural gas Navien boiler, which is pretty much what you see in most new home builds. I have the Navien combi boiler that heats my domestic water also, but you probably won’t need that. You absolutely need to insulate the slab or you lose a lot of heat. They are also burying full sheets of 2” foam board around the perimeter of the slab out 4 feet to keep the frost away.
Good luck with your project.

[Gunner55]

We have a floor drain in our garage at the lake & break out a couple window fans sometimes to help dry the blower & wheeler off after moving snow. There is a air handler in the garage too, as there can be quite a bit of humidity which leads to condensation in the windows at times. We don't want that to freeze.

[Rodwork]

When I built my shop I put in 2” ridged pink insulation and pex pipe.  Finally got the boiler in and running this year. I am running off of a gas boiler. One thing no one told me was how much condensation the boiler makes. It is around a gallon a day. Make sure to have a floor drain to run it to.

edit: 32'x35' shop, one zone.

[MN RACK ATTACK]

As someone who has worked on the wholesale side of selling these type of products for years. NEVER have the concrete people size, design or install the tubing. They dont care if it works. Have a respectable heating company that specializes in it design it and lay it out on top of closed cell foam insulation. Never put it in a bed of sand unless you want ongoing problems. Also for quick recovery heat, put an overhead unit in for that reason.
Scenic had a very good analogy of the the pros and cons.
Putting a bathroom fan with a humidistat that controls the humidity will help along with floor drains.
Just giving an opinion, take it for what its worth.