Heated Shop Cement Floor

Check out some this old house videos, those guys put them in just about every project they build...

There are some nice videos on youtube of laying out different types of systems. Neighbor has it in his farm shop, laying on warm concrete sure beats cold and damp floor and your tools and parts stay bone dry.

We have a heated floor in our shop, keep it between 50 and 55 degrees Your feet are warm and you can work on the floor under things. We keep the skidsteer in the shop all winter so it is ready to go to feed cattle or plow snow. When you are working in there a sweat shirt is warm enough and if you are doing something outside and going in and out it isn't so warm with winter clothes, If you would be working in there all day you can turn it up to short sleeve temps. Floor heat is pretty adaptable you can run it off outside boiler, gas or electric water heater or a small inside boiler. You could even set it up to take heat off a wood stove.

Edited by DanWi - 14 Dec 2019 at 9:29pm

Edited by DaveKamp - 15 Dec 2019 at 9:49am

jaybmiller wrote: Dave brings up a GREAT point !!! Use SEVERAL 'zones' NOT just one !  Better to have 4, 100' runs than 1,400'. That way if one pipe gets a leak, the other 3 will keep working !!

I love my in floor heat, set at 53,havent checked but have heard the ceiling temp would also be at 53 unlike forced air.

DaveKamp wrote: Jay just noted one of the two reasons why I'm putting my big shop's PEX down in the filler material BELOW the slab, but above the insulation... First... when you drill into the concrete, if the PEX is BELOW the concrete, chances of hitting it are much less.  Second... if the concrete expands, contracts, or cracks and shifts, and the PEX is BELOW the concrete, the shifting of concrete will not shear the tubing. And one other thought... the tubing is MUCH less expensive than it was 15 years ago... and much less expensive than the concrete.  Putting tubing down before a pour doesn't commit you to heating it with that tubing, and it doesn't LIMIT you to heating it hydronically- it simply gives you the option.  You can heat it with IR burners on the ceiling, or a forced air furnace.  Furthermore, hydronic doesn't care WHERE the heat comes from... as noted previously, you can use any old water heater, and for control and circulation, just put an old-school mercury-switch thermostat on the wall controlling a relay that powers the pump. My neighbor's attached garage is an excellent example... he's got most of 30 x 36 floor less a spot for his basement stairway and kitchen/hallway doorstep.  He's got about 1000 square feet of concrete, and under it, 400ft of 1/2" pex .  The first loop goes all the way around the perimeter, about six inches in from the edge under the overhead door seals, and about eight edges from the outer walls and back yard door.  The second loop goes back and forth for two passes on 1 ft intervals at the overhead door end, and the third loop fills in the rest of the floor. They're all about 110ft total, fed with a simple manifold and a 3gpm pump.  The water heater is a 15 gallon, and temp is set on the absolute-lowest-setting. Concentrating more heat towards the edges makes up for the fact that most of the floor's heat is lost there.  Concentrating heat under the door thresholds helps keep the doors from freezing to the ground. The water heater is a high-efficiency unit, with it's exhaust in PVC going out the east wall.   Most building codes will require a furnace or water heater to be elevated a certain height off the floor... this is so that motor fuel vapors can't concentrate high enough to contact the burner or pilot light, and cause an explosion... As Jay noted, thermosyphon WILL work on hydronic heating, however, the water heater's highest point MUST be below the floor, and to work effectively, there must be only one loop, and the water heater's cutoff point MUST be able to go all the way down to whatever room temperature you want to limit to.  Better control and efficiency is to run a for-purpose pump with a relay and thermostat.

   As a cement finisher I love the idea of the tubes in sand, there is nothing worse then finishing cement on top of foam insulation. I also like the idea of the rebar not touching the tubes.

You can get thermostats designed for in-floor heating. They use a floor temperature sensor in conjunction with the room sensor so that the floor doesn't overheat before the room temperature is satisfied. I just completed designs for a child care facility that wanted warm floors. Because there are  several rooms there are 31 loops any where from 125' to 310'. The majority average about 250'.

DonBC wrote: i forgot to add that you want the loops under air pressure during the concrete pour in the event that a loop gets damaged during the pour. A lot easier to find and fix than later after the concrete has set.

X2

Since this is the subject, I have tubes in my shop floor but it was installed 30 years ago- just a countinous piping 3 ft apart -30-50ft shop, 1 hook up in and 1 out - I have a Hardy wood furnace to heat it and the house but darn it eats the wood , finally unhooked the shop- so my question and thoughts are now is this- was thinking of hooking up a 40 gallon electric hot water heater in the system as a helper to heat the water, the pump on the wood furnace would be the pump as it is hooked to the thermostat already , would run the water into the water heater from the wood furnace then it goes to the floor and return to the wood furnace , the furnace temp is set at 150, the water heater would be set at the lowest setting- will need check valves on in and out to the water heater - why wouldn't this work ? Just looking for opinions and advise , thanks

Edited by DougG - 16 Dec 2019 at 12:33pm

Doug it would work as a back up but not a helper the 150 boiler temperature won’t let the water. Heater come on now if the fire goes out the water will cool of and the water heater will come on and help keep from freezing   Ps we are building house now it gets radiant through out but also getting a hot water coil in with the ac system radiant is slow and steady but if ya need to warm up the house quick turn the stat up on the ac and get it warm quick

Edited by bradley6874 - 16 Dec 2019 at 2:16pm

I like to use radiant heat. The one that is a 4" tube that hangs 10 or 12 ft. above the floor and runs the length of my shop.

We ran radiant on NatGas in WY, large wellhead shop full of forgings with pallet racks 3 & 4 high. When boys pulled in at 4-5:00 AM with Power Strokes via the overhead doors originally set up to drive tractor trailers through, recovery time was truly impressive as all that iron on the shelf held that heat. Pulling equipment down off racks it was always warm to the touch.