Every builder in cottage country gets this question. “I am pouring a slab for the shop. Do I need tubing? Do I need a permit? How big a heater?” The answer depends on what the building is and how you will use it.
Here is how to think about heat for garages, shops and bunkies, the options that work, and the questions to ask your building department before the concrete truck shows up.
The best for a shop you use often. Warm floor, steady heat, and the heat stays when the big door opens. Insulate under the slab. See radiant slab design.
Cheap and quick for occasional use. Fuel-burning units need to be rated for garages and installed to their instructions.
Heat in winter, cooling in summer, efficient. Great for bunkies and smaller shops.
Simple for a small bunkie. Expensive to run for a big space. See electric baseboard.
It depends on the size of the building, whether people sleep in it, whether it has plumbing, and what the heat is.
Departments differ. Sarnia’s hydronic heating guide, for example, does not require a qualified designer for heated slabs in accessory buildings, and only asks for a heat loss when the system is the primary heat. Other departments want more. A bunkie people sleep in is treated more seriously than a workshop.
One phone call to your building department before the slab goes in tells you what they want. Once the concrete is down, your options shrink.
Without it, a heated slab heats the ground.
Cheap now, impossible later.
A shop at 10 C needs far less than one at 20 C.
Any fuel-burning heater means a carbon monoxide alarm.
A big overhead door is the largest heat loss in most garages. Insulated and sealed.
If people sleep there, treat the heat and the smoke and CO alarms seriously.
A heat loss for the building gives you the size of the heater or the slab output. For a radiant slab we design the tube spacing, loop lengths, manifold and heat source. See radiant floor design and electric boilers.
We build in Tiny Township and have poured plenty of heated shop slabs. Get the design done before the concrete truck is booked.
Pouring a shop slab? Send the plan and how warm you want it. We size the heat and lay out the tubing.
Get Free Quote →It depends on the building, the size, and the heating. Some departments treat a heated slab or unit heater in an accessory building lightly, and Sarnia’s hydronic guide, for example, needs no special designer qualification for accessory buildings. Others want more. Ask your building department before you pour.
If the heating is the main heat for a building people sleep in, expect the building department to want to see how it is sized. If it is a small, simple space heater in a seasonal bunkie, the answer may be different. The size and use of the bunkie decide a lot.
For a shop you use every day, a radiant slab is hard to beat: warm floor, heat stays when the door opens. For occasional use, a properly rated unit heater or a ductless heat pump is cheaper to install.
Fuel-burning equipment in a garage has its own installation rules, because of gasoline vapour and car exhaust. Use equipment rated for garages and installed to its instructions, and put in a CO alarm.
It depends on the insulation, the doors and how warm you keep it. A well-insulated shop held at 10 C needs a fraction of what a drafty one held at 20 C needs. A heat loss gives you the number.
Many owners do. Tubing in the slab is cheap. Adding it later means a new slab. Insulate under the slab too, or the tubing will heat the ground.
Send the building plan, insulation details and how you will use it. We calculate the heat loss and design the radiant slab or heating.