Best of both floors?

[Jeremy Gibson]

As I was shivering in my insulated but unheated garage tonight I started thinking about the ideal environment. I've read many posts here about the benefits of radiant heat in a concrete slab, but also of the softness of a wood floor. I also like the idea of being able to run electric and DC under a subfloor. I can see in my minds eye how to add a raised floor w/ sleepers to a slab and I can see how to add tubes and slurry to a slab to create the heat source. Can you combine the two and still get heat from the floor?

Here is what I mean - picture a concrete slab w/ radiant heat. Then add the sleepers, 2x6 or 2x8 joists and some type of flooring (3/4" T&G ply or hardwood). How do you prevent the screws or nails that attach the sleepers from punctering the water tubes? Would construction adhesive alone do it (I wouldn't think so). Assuming correct attachment w/out puncture, would the heat rise through the raised floor and still heat a shop?

Thanks for letting me ramble.

[Jamie Buxton]

Jeremy --
If you're willing to put sleepers and a wood floor above your garage slab, consider a slightly different kind of in-floor radiant heating. There are now many sources for systems in which the warm water flows through PEX tubes which are embedded in slots in the (wooden) subfloor. There's no concrete involved at all. Warmboard is one brand, but there's lots out there.

[Ted Shrader]

Jeremy -

Jamie's idea about heat in the wooden floor is what came to mind as I read your post. No worries about puncturing the tubes as you lay down the sleepers. Besides, with heat in the concrete and 8" sleepers above that, don't think too much heat would make it up to keep you warm.

Ted

[Charles McKinley]

Hi Jeremy,

www.radiantcompany.com and www.radiantec.com can provide you with more info. I just lost the post I had typed up. I'll reply again later today.

[Jeremy Gibson]

I took at look at Warmfloor - wow! That would be the perfect solution. Radiant heat IN the subfloor instead of below it. Of course, I can imagine the response when I tell SWMBO that I want hardwood floors in the shop. I'm sold, but now it's my turn to sell. Thanks!

[Jason Roehl]

I took at look at Warmfloor - wow! That would be the perfect solution. Radiant heat IN the subfloor instead of below it. Of course, I can imagine the response when I tell SWMBO that I want hardwood floors in the shop. I'm sold, but now it's my turn to sell. Thanks!

I don't know that I'd get too crazy about hardwood floors in the shop. It sounds great, but you must remember that just a tiny bit of dust on a hardwood floor makes it EXTREMELY slippery, a situation that is not safe around power (or even hand) tools. You might be better off just putting down the radiant tubing, pouring an inch or two of lightweight concrete over it, then using rubber horse-stall mats or the like in your busiest areas for standing comfort.

Just my $.02.

[Jamie Buxton]

Well, you don't have to put (expensive) hardwood on top of the Warmboard. You could use any other material which can be used for a shop floor. For instance, you could use sheets of subfloor-class plywood, or OSB. Or you could use vinyl sheet or tile. Or if you really want hardwood, some suppliers (e.g. Lumber Liquidators) offer low-grade oak for as little as a buck a square foot. It is mostly shorts, and may have knots or splits, but those defects could be acceptable in a shop floor. The big caution with nailing down hardwood on a radiant-heat floor is that you must be careful to not nail into the water tubing.

[Ronald Thompson]

You might want to provide insulation on top of the concrete. The thermal mass of the concrete will absorb alot of the heat intended for the room. The rigid foam with the reflective foil would be a good choice. You will have to decide how thick you want it, taking into consideration clearances to the surrounding doors.
Ron

[Jamie Buxton]

You might want to provide insulation on top of the concrete. The thermal mass of the concrete will absorb alot of the heat intended for the room. The rigid foam with the reflective foil would be a good choice. You will have to decide how thick you want it, taking into consideration clearances to the surrounding doors.
Ron

Yeah, insulation between the concrete and the radiant elements is pretty much required.

Another thing you might consider while you're putting in this floor is to make the new floor horizontal. All garage floors slope down toward the big door, so everything you put on it tilts. Horizontal would be much nicer.

[Jim Becker]

I don't know that I'd get too crazy about hardwood floors in the shop. It sounds great, but you must remember that just a tiny bit of dust on a hardwood floor makes it EXTREMELY slippery, a situation that is not safe around power (or even hand) tools.
Unfinished hardwood strip flooring is what I would use in this instance, not the pre-finished (or post-finished) slippery stuff! Lumber Liquidators often has it very inexpensively, too...

[Jeremy Gibson]

Another benefit of the unfinished strip flooring is the ability to see the water tubes while installing it and therefore prevent any nailing through the tubes. Lumber Liquidators has oak (slightly damaged) for $0.99/sq ft and pine for less than $2.00/sq ft. If I get to build a shop, I would have the slab poured level instead of slopped, but any irregularities could be evened out with the sleepers.

So what I now have pictured is a concrete slab with a vapor barrior. then sleepers and floor joists installed with rigid insulations between them. In the joist space I'd run electrical and dust lines. Top this with WarmFloor subfloor and an unfinished strip floor. I think I would describe this space as "sweet!"

[Jamie Buxton]

And, while you're at it, insulate the walls and ceiling, and make sure the big garage door seals well. No sense in trying to heat the whole out of doors!

[Jeremy Gibson]

And, while you're at it, insulate the walls and ceiling, and make sure the big garage door seals well. No sense in trying to heat the whole out of doors!
That goes without saying. My original plan calls for a 3 car garage size building with one bay dedicated to the tractor and automotive work. I'd keep concrete there and have an overhead door. The other two bays would be the woodshop with the wood floor. I was thinking of an 8' wide sliding door in that space, but I'm beginning to doubt the ability of a slider or overhead to seal well enough. My current garage has a typical 2 car overhead door and the cold air rushes right in. I wanted a large enough door to get large projects in and out. I suppose I could go with a set of french doors and get a good 6' opening. Comments?

[Jim Becker]

Jeremy, I used double, out-opening insulated steel doors (pre-hung) with security hinges and windows in the upper portion for additional natural light. They give a 6" opening which is more than sufficient for any kind of project or material and are the normal 80" or so tall. Out-opening is important as you don't want doors taking up valuable shop space; but you need the security hinges to avoid someone taking them appart to gain entry. I have two of these doors for my shop (they went in where two garage doors previously lived) and each cost approximately $480 from the local "real" lumber yard.

[Brian Buckley]

Jim,
Good looking shop, especially the doors. My overhead doors are a pain for dust collection pipeing and electrical outlets.

Brian

[Jamie Buxton]

Jim's steel doors are especially cool for weatherstripping. They come with (or can be eqipped with) flexible magnetic weatherstrip. It is kinda like the seal on your refrigerator door: the magetism pulls the door closed and seals it with a nice thunk. It is a more secure seal than most on wood or fiberglass doors.

[Jim Becker]

I don't have any feature like that, Jamie, but the doors don't leak...the factory weathersrtipping is quite good and the glass is double pane/insulated. In addition to the deadbolts I use, I also have them pinned top and bottom for additional security and to insure they are totally sealed in the weather.

[Mike Wilkins]

I can not reference the issue( I am at work right now), but Fine Homebuilding magazine had an article on radiant in floor heating. This was a system of using a special plywood with radiant surfaces and channels cut into it for the heat tubes. You did not have to pour a skim coat of soupy concrete for the installation of the tubes.

Go to the Taunton web site for Fine Homebuilding and do a search for the issue. You can order back issues. It was one of the last 1 or 2 issues.

Good luck and watch those fingers.

[Wes Bischel]

My inlaws have radiant heating in their home. It has both tile and hardwood flooring over a plywood sub floor. It works well, though be prepared, radiant systems do not react as quickly as forced air systems. So if you want to keep the temp at 60 degrees and turn it up when you come in to work, expect it to take some time to come up to temperature.

Wes

[Jamie Buxton]

Steel doors with magnetic weatherstrip are pretty much standard here for new construction for the door between living space and an attached garage. The steel cladding fulfills the fire resistance code, and the magnetic seal provides reliable sealing against carbon monoxide and cold air.

Below is a pic of the magnetic weatherstrip. The barb at the right goes into a kerf in the door stop molding. The rectangular portion a the left is a flexible magnet, and the oval in the middle provides compliance. The stuff costs pretty much the same as any other kind of weatherstrip, and is sold by most places which sell weatherstrip.