Which shop floor would you do?

[Mike Williams]

In a post last month (http://www.sawmillcreek.org/showthread.php?t=38610), I shared my initial plans for a 1,200 sf shop that I plan to build next Spring when we return from Ireland. Carrying on from that, I have some questions for all of you regarding shop floors.

The shop will be in Southeast Michigan, and be heated and air conditioned. The two givens are that it will have hydronic floor heating and a wood floor. In my earlier posting, I stated that the shop would have a concrete slab on grade with the water tubing in the concrete, and topped with plywood / flooring. Generally, it would look like this:

Option 1 - Concrete slab

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I had a lot of helpful feedback on this posting, including a concern that the thick wood floor over the concrete mass would not be a very responsive heating system (maybe OK when it finally heated up, but not very fast to heat up or cool down.) To be fair - I expect to leave the heat on during the colder months all the time, so maybe that isn’t too critical.

I also wonder if the plywood over the concrete really gives me the benefit of a ‘softer’ floor or not. I know it protect my tools when I drop them,http://www.sawmillcreek.org/images/icons/icon8.gif but I also want to ensure I protect my knees and feet. I know I can’t just raise the wooden floor on 2 x 4 sleepers over the concrete slab / buried tubing without really degrading the heat transfer.

In trying to see if there was a better answer, I did a search through SawCreek, FWW and across the web. The only product that seemed to be set up for a better wood floor over a concrete slab is Warmboard. That’s a 1 1/8” thick structural sub floor with a thin aluminum top skin and grooves for ½” hydronic tubing at 12” centers. The hydronic heating ends up just under the finished floor. They don’t recommend attaching the Warmboard directly to a concrete slab, so that option would look like:

Option 2 - Concrete slab with Warmboard

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I like Option 2 from a design standpoint, but it seems like it is going to be a lot more expensive than Option 1. I don’t have actual prices on the Warmboard, but I’ve seen references to it being about $3 / sf (materials only).

The final option gets rid of the concrete slab and goes to a basement or crawl space. I can’t really justify the basement or crawl space for the shop, so if we go this way, it will be because the floor is far superior to the other options, or because the gentle slope on the site and the required 4‘ deep footings makes it (almost) a wash in costs. That option with the Warmboard would like:

Option 3 - Floor joists with Warmboard

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Are any of these a really good, or really bad option? Is there another design I should be considering?

Like always, I appreciate your suggestions and expertise.

Thanks!

[Jim O'Dell]

Mike, I'm no hydronic expert, but I do watch some on This Old House and Hometime. :rolleyes: From the comfort standpoint, I think #3 would be best, then 2 then 1. Somehow I think you lose the comfort advantages of a wood floor if it sits on concrete. Maybe others in the know, will know different. But would think part of the comfort of a wood floor would be in the "bounce" or give it would have on joists.
Other than that, for heat I think any of the 3 would work, with #s 2 and 3 being best. Jim. (Who's working on his cyclone wiring in an unheated, uncooled shop with concrete floors.)

[Art Mulder]

Mike,

(disclaimer: not a builder, never built a home with radiant in-floor heating, just read a lot, and have an inquiring mind...)

RE: Option #1. Have you considered using a dimpled material such as the Delta-FL product? ( http://www.deltafl.com/) From what I've heard, you can put laminated flooring directly over delta-fl. It'll certainly have some give.

Also - Why would you not put the styrofoam below the slab in option #2?? From everything I've read, insulating outside/under the concrete is really a good idea, since you gain all the thermal mass of the concrete. In summer it helps keep you cool, in winter it helps keep you warm.

I know a fellow on one of the Canadian WW'ing forums, who has a garage shop in Regina, Saskatchewan - cold winters there. He put 2" of foam beneath his slab, and really, really, notices a comfort benefit. (I forget, he either uses a radiant tube heater, or a forced air heater of some kind. Whatever, it wasn't in-floor). For flooring he just bought a whole bunch of those foam interlocking pads that you can get in Home Depot. Cheap and comfortable. I have some myself in my basement shop in front of the workbench and it is comfortable also.

hope this is some help.
...art

[Mark Pruitt]

Can't offer any help as to floor material, but IME anti-fatigue mats are the very best thing I've done for my feet (and knees).

[Ben Grunow]

I have only used radiant heating for floor warming (comfort) not heating so I can't advise on the best system but intuitively it seems that the less layers of wood there are between the source of heat and you, the better the heating system will work.

I think you could make the plywood with grooves yourself for much less money. Find out what the outside diameter of the PEX pipe is and but some ply that is a little thicker by about 1/16" or so. Rip it to the desire spacing for the pipes and screw it down. THen using a circle cutting jig on the BS or trammel with router make the end pieces where the pipes turn around. THen add a layer of 3/4 ply for the floor. So you would have 3/4" subfloor PEX thickness layer and another 3/4" layer. Just work out the layout with your heating contactor so the bends aren't too toght for the PEX because it will kink.

I bet this will be cheaper than a concrete floor and might give you a crawl space which is nice for DC runs to the TS or whatever. THe area most likely will be excavated anyway. PLus the framed floor goes quick where as the concrete floor with pipes takes time. Just MHO.

[Joe Mioux]

MIke:

I do know something about hydronic heat. I have 20 miles of tubing spread out across 12,000 sq ft of greenhouse space, a branch store that occupies 2500 sq ft with it and another 760 sq ft greenhouse with it.

For you application, my store is most similar. I have concrete floors and a generous amount of baffled style anti-fatique floor mats. This is your best option.

Why? Because you are heating your thermal mass and not letting anything interfere with it. Remember your knees and feet don't and won't care what your equipement is setting on. Use the mats in your work area and let the rest of the thermal mass heat the room.

I can't imagine putting wood over a thermal mass. Just seems conterproductive to me.

If you have any questions or would like some pics of my various set-ups let me know.

Joe

[James Kuhn]

I don't have too much experience with these things but I think the thermal mass question would depend on how often the shop would be occupied and/or how continuously you would want to be running the system. If you are going to be in the shop all day having a large energy reserve would make a lot of sense. If not, you would waste a lot of energy heating and cooling the mass when you are not there. The slab is certainly going to be a lot cheaper, the LVLs or Glulam beams that you would need to carry a shops load would be pretty pricey. If you did go that direction I would mount the tubing directly to the sub floor and leave an airspace between them and the insulation, plus I would put the vapor barrier below the crawl space. It will be a lot easier to service the piping as well as any other stuff you run under there (dc, electrical, etc.).

[Jim O'Dell]

I hadn't thought of this before, but looking at James' picture of the tubing under the subfloor for radiant heating, there would be no room for floor mounted electrical or DC ducting!! Jim.

[Jamie Buxton]

If I were building a shop from scratch -- with luxurious stuff like heating -- I'd use a perimeter foundation, a crawl space, and wood floor system. The crawl space gives you a place to put wiring, dust collection ducting, and compressed air if you want. With a wood floor, is it relatively easy to reroute all of that stuff if you get a new machine or otherwise revise the shop. For heat you could do hydronic, but in a big open space like a shop, forced air is lots less expensive.

Concrete, or other means of achieving a big thermal mass, works well in a place which you heat all the time, like your home. Unless you spend lots and lots of time in the shop, you'll spend less money by heating the shop only when you're there. In this situation, the thermal mass works against you. It makes the shop slower to come up to working temperature.

[Matt Meiser]

I'm also in S.E. Michigan. I've got an existing concrete floor, but was very close to building a shop before we found this house. I talked to three local heating contractors and none of them wanted to give me a quote on in-floor heating due to the cost. All three recommended various forced air systems. I ended up going with one of the Hot Dawg style heaters mounted in the corner of the shop. The logic that they gave me was that if I had a well insulated shop, the benefit of the radiant heat wouldn't be that great. They said that its prime benefit for a shop is being able to open a large door and not lose heat and that's not something you tend to do in a WW shop very often. I heat my shop at least 45 degrees all winter. The floor tends to stay warm once warmed up, and I can very quickly raise the temperature to a comfortable working temperature (about 60 degrees for me) whenever I want to work out there. And when I'm finishing or doing a glue up with temperature-sensitive glues, I can raise it another 10 degrees in a matter of minutes.

The Hot Dawg heater was so easy to install I did it myself at a cost of under $800 complete. I was getting rough estimates of $3-4K for a smaller shop with radiant.

If you are thinking about resale value, I would definitely go concrete around here. If you want wood over that, let it float on the concrete. There are an aweful lot of people with antique/classic/hot rod/race cars that will be looking for a shop around here. A permanent wood over concrete or all wood floor on a crawl space will be a deal breaker for them.

[Al Willits]

I think I would use forced air also, but if your going to use under floor heating make sure of at least a couple of things, insulation between the ground and the heating coils/floor, and what your gonna do when the system leaks.
Replaceable tubing and easy access would be a must if I were to install it.
Contrary to popular belief, they do start leaking sometimes.

Also as pointed out, the more insulation you have between the coils and the room side of the floor, the more delay you have in heating, maybe not a problem if continually heated.

Al

[Art Mulder]

Hey, Mike,

I went digging, and found the info on the fellow in Regina who built a shop with insulation under the slab. If you want to read the whole story, go here: http://gansk.sasktelwebsite.net/new-workshop.htm

But here is the basic part about the floor:


... With the insulated concrete forms providing 3" of insulation 24" below grade and an insulating blanket under the pad, the concrete floor doesn't get cold. Not even during the two weeks of -30°C to -38°C we had shortly after Christmas. The housewrap, R20 walls, R28 ceiling, a single window and no overhead door makes for a nice cosy place to hang out. I'm using a 4800W/240V electric construction heater to heat the shop. Even during that cold snap after Christmas it seldom ran more than half the time.


Hope this helps
...art

[Frank Fusco]

My only experience with floor heating was when I was a kid, my folks had a slab floor cottage in central Michigan. In cold weather our feet would be on fire and the rest of our body shivered. And our feet would swell up, sometimes wouldn't fit in our shoes.

[Jim Becker]

My only experience with floor heating was when I was a kid, my folks had a slab floor cottage in central Michigan. In cold weather our feet would be on fire and the rest of our body shivered. And our feet would swell up, sometimes wouldn't fit in our shoes.

This was true of the earlier systems that used very hot water. Today's hydronic systems use much more moderated heat, whether they are in-floor or not, and it's much more comfortable. There is less "pain" during seasonal transitions, too.

[tod evans]

mike, i would not put hydronic heat in a shop for two reasons, first being cost. both to install/opperate and maintain. second reason being the type of flooring systems you`re looking at are designed for residential use i`d be leary of point loading a floor of any of the designs you`ve shown? a workbench for instance could very well place more load on the contact points than a loaded refridge... it would seem to me that by the time you build up enough floor strength to set a shop on that any benefit of radiant heat would be lessened by the shear mass of the floor itself?
if you`re installing a boiler for your residence you might look into some type of radiators for the shop? otherwise i`d go with a name brand forced air system designed so that you can access the "a" coil easily for cleaning. a shop no matter how good the dust collection, will clog the coil quickly due to the nature of the beast. so best to design with service in mind.....02 tod

[Mike Williams]

Thanks to all of you for some great input. Like many of you, I've never had a chance to build a shop from scratch before - it's always been a concrete floor in the basement. So I want to get this right - but not spend a fortune getting there.

Based on what I had read from others when asked the question "what would you do differently", I thought the floor radiant heat and the wooden floor was a natural. But the concrete definitely made it more difficult.

I also thought the radiant heat was superior to forced air because it didn't blow the dust around. But with a separate finishing room (and a good DC and air cleaners), maybe that is less important.

Regardless of using a concrete slab or a suspended floor, with the radiant floor heat I didn't plan on running electrical / ductwork underneath. With 10' ceilings, I can keep the ductwork above 9' and I'd rather have it out where I can see it. I can also use drop cords over the benches / tables and run electrical conduit down the sides of the vertical ductwork for the tablesaw / planer / jointer in the middle of the room.

Here's where my head is right now:

Insulate the walls with closed cell foam insulation - superior insulation and vapor barrier.
Concrete slab on grade with 2 - 3" of insulation under the slab. No heat in the slab.
Lay a floating plywood floor (two layers) over the concrete. Either place on 2 x 4 sleepers over the concrete slab with insulation between the sleepers (vapor barrier under the insulation), or use a product like the Delta FL insulating pad m/vapor barrier.
Use forced air heat in the main shop (but also looking at ceiling mounted gas radiant heat).
Use electrical ceiling panel radiant heat in the finishing room / bathroom - clean and no blowing air.If I use the Hot Dawg style heaters hung from the ceiling, I can even get rid of the mechanical room and use the space for something else.http://www.sawmillcreek.org/images/icons/icon10.gif

Any follow-up thoughts from anyone?

[Jim Becker]

Mike, don't forget to switch your framing to 2x4 if you're using the spray-in closed cell insulation...it helps to balance the cost of the insulation and you still get R-19+ in the walls. The stuff really stiffens the structure, too.

[Marty Walsh]

mike, i would not put hydronic heat in a shop for two reasons, first being cost. both to install/opperate and maintain. second reason being the type of flooring systems you`re looking at are designed for residential use i`d be leary of point loading a floor of any of the designs you`ve shown? a workbench for instance could very well place more load on the contact points than a loaded refridge... it would seem to me that by the time you build up enough floor strength to set a shop on that any benefit of radiant heat would be lessened by the shear mass of the floor itself?
if you`re installing a boiler for your residence you might look into some type of radiators for the shop? otherwise i`d go with a name brand forced air system designed so that you can access the "a" coil easily for cleaning. a shop no matter how good the dust collection, will clog the coil quickly due to the nature of the beast. so best to design with service in mind.....02 tod

Mike,

Tod's correct about a 'normal' engineered I-joist floor. But, you *can* have one engineered to support the type of loads encountered in a wood shop. You've seen my shop thread, so you know it's possible. But, be prepared...it will be spendy!!

In my case though, with the grade of the site, the engineered floor system, even being OVER engineered, was less expensive than grading and having a slab installed. Plus I get my wooden floors! :D

Good luck with your shop. Be sure to keep us informed as you progress. It'll be nice for me to be able to watch someone ELSE doing all the hard work for a change...

- Marty -

[Jerry Strojny]

Mike, I am an engineer in Wisconsin in the heating and cooling business and I wouldn't abandon the radiant idea just yet. The advise I would give you regarding your 3 options was somewhat suggested already. An "exposed" concrete slab is the large thermal mass you want to heat an open space like a shop. As soon as you cover it (wood, carpet), you reduce it's effectiveness. The covering absorbs some of the heat before it gets to start working for you.
If I was doing a slab on grade shop, I would want radiant heat. I would leave the concrete as the flooring and use anti-fatigue mats were I am working. And then I would insulate the "crap" out of everything. At least 2" under the slab, min of R-19 in the walls, and then as close to R-40 or 50 at the roof. Not having a forced air system blowing dust around sounds good to me too. The temprature of the water in the pex piping should be around 95-110 degrees. You get a nice even heat throughout the whole building. I haven't completely read your original shop thread, so if I made some assumptiond that are way off, I am sorry. So, for whatever my 2 cents may be worth....

[Mike Williams]

Mike, don't forget to switch your framing to 2x4 if you're using the spray-in closed cell insulation...it helps to balance the cost of the insulation and you still get R-19+ in the walls. The stuff really stiffens the structure, too.

Jim - I haven't forgotten. I'm planning on the closed cell with the 2x4 wall construction, in lieu of 2x6 with fiberglass. Everything I read sounded very positive on the foamed insulation.

Thanks, Mike

[Mike Williams]

Mike,

In my case though, with the grade of the site, the engineered floor system, even being OVER engineered, was less expensive than grading and having a slab installed. Plus I get my wooden floors! :D

Good luck with your shop. Be sure to keep us informed as you progress. It'll be nice for me to be able to watch someone ELSE doing all the hard work for a change...

- Marty -

Marty - thanks for taking the time from your fishing to respond. I've been following your progress closely, and am impressed by your dedication to the task. I too plan on watching someone else building most of my shop (building the whole shop just isn't my cup of tea).

I know I can do the wood joist floor if it all works out that way. Since I wouldn't be too concerned about the usability of the 'basement', I can have extra columns and steel beams to limit the span of the joists.

[Mike Williams]

...I wouldn't abandon the radiant idea just yet...If I was doing a slab on grade shop, I would want radiant heat. I would leave the concrete as the flooring and use anti-fatigue mats were I am working...

Jerry - thanks for the comments. I'd have to get my head around having the concrete floor with the cushioned mats rather than the wood flooring. I understand the advantages from a heating standpoint. I'm just not sure I want to give up the benefit of the wood floor.

It looks like something may have to give - I'm just not sure what. I'll be back in the US in October where I hope to be able to talk to some local builders and HVAC contractors.

Maybe one of the compromises would be to put in the wood floor at the bench / assembly table area and finishing room (where I'm standing a lot and using hand tools), and the concrete with mats in the power tool area.

[Matt Meiser]

It looks like something may have to give - I'm just not sure what. I'll be back in the US in October where I hope to be able to talk to some local builders and HVAC contractors.

Let me know when you are back--I'm a little more than an hour south of Howell if you want to see what I did with my shop.

[Marty Walsh]

Marty - thanks for taking the time from your fishing to respond. I've been following your progress closely, and am impressed by your dedication to the task. I too plan on watching someone else building most of my shop (building the whole shop just isn't my cup of tea).

I know I can do the wood joist floor if it all works out that way. Since I wouldn't be too concerned about the usability of the 'basement', I can have extra columns and steel beams to limit the span of the joists.

Mike,

I knew I was gonna catch grief for posting that about 'having' to fish... :p

I'm glad you'll be able to watch someone else build your shop FOR you. There's no way I could have afforded to do that. The quotes I got ranged from $80 to over $100/sq ft!

- Marty -

[John Bush]

Hi Mike,
I built my 1560 sgft shop(hobbiest)from scratch and chose the in-slab radiant system. In the Pacific NW we only need to go 18" for the frost line so not dealing with a crawl or basement simplifies the design. I used 6" of rock, 2" of dense cell foam 6 mil vapor barrier 6" mesh, I tied the hydro tubing to the mesh, then poured the slab on top. I used an 80 gal nat gas hot water heater, instead of a boiler, a 4 zone manifold, a relay and pump, and a thermostat to control the system. We don't get the winter weather here that you get in Michigan, But I think this type of heat is the most comfortable and possibly the most efficient. I keep the temp ~50 during the week when I have limited shop time, and crank it up to 65 when I plan on being in the shop for longer periods. I does take some time raise the temp, but it stays comfortable even when you have to open the garage doors. I think you should keep this at the top of your short list. I now you will be happy system. The only addition I would make now would be a small wood burning stove. I heated my old shop with an old pot bellied stove and really enjoyed the "feel" of that type of heat, but more importantly, I've got boxes, barrels and bags of scraps that I can't bring myself to throw away and I would have an extra 100 sqft of space if I would get rid of it, so keep that in mind as well. Goos luck, JCB.

[Ron Blaise]

In a post last month (http://www.sawmillcreek.org/showthread.php?t=38610), I shared my initial plans for a 1,200 sf shop that I plan to build next Spring when we return from Ireland. Carrying on from that, I have some questions for all of you regarding shop floors.

The shop will be in Southeast Michigan, and be heated and air conditioned. The two givens are that it will have hydroponic floor heating and a wood floor. In my earlier posting, I stated that the shop would have a concrete slab on grade with the water tubing in the concrete, and topped with plywood / flooring. Generally, it would look like this:

Option 1 - Concrete slab

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I had a lot of helpful feedback on this posting, including a concern that the thick wood floor over the concrete mass would not be a very responsive heating system (maybe OK when it finally heated up, but not very fast to heat up or cool down.) To be fair - I expect to leave the heat on during the colder months all the time, so maybe that isn’t too critical.

I also wonder if the plywood over the concrete really gives me the benefit of a ‘softer’ floor or not. I know it protect my tools when I drop them,http://www.sawmillcreek.org/images/icons/icon8.gif but I also want to ensure I protect my knees and feet. I know I can’t just raise the wooden floor on 2 x 4 sleepers over the concrete slab / buried tubing without really degrading the heat transfer.

In trying to see if there was a better answer, I did a search through SawCreek, FWW and across the web. The only product that seemed to be set up for a better wood floor over a concrete slab is Warmboard. That’s a 1 1/8” thick structural sub floor with a thin aluminum top skin and grooves for ½” hydronic tubing at 12” centers. The hydronic heating ends up just under the finished floor. They don’t recommend attaching the Warmboard directly to a concrete slab, so that option would look like:

Option 2 - Concrete slab with Warmboard

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I like Option 2 from a design standpoint, but it seems like it is going to be a lot more expensive than Option 1. I don’t have actual prices on the Warmboard, but I’ve seen references to it being about $3 / sf (materials only).

The final option gets rid of the concrete slab and goes to a basement or crawl space. I can’t really justify the basement or crawl space for the shop, so if we go this way, it will be because the floor is far superior to the other options, or because the gentle slope on the site and the required 4‘ deep footings makes it (almost) a wash in costs. That option with the Warmboard would like:

Option 3 - Floor joists with Warmboard

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Are any of these a really good, or really bad option? Is there another design I should be considering?

Like always, I appreciate your suggestions and expertise.

Thanks!






Mike, I've already had a concrete floor in one of my shops. I now have a wood floor and really notice the difference in comfort. Given a choice I vote for wood floor, Your feet & legs will thank you.

[Bob Huddleston]

First, hello fellow Michigander! Near Bay City here :)

I have my basement floor heated with tubes and hot water, and we love it. Not only does it keep the floor and basement warm, the heat filters up to our living spaces as well. Here in MI, although the winters are not terribly cold, the constant heat is nice. Another postive is that once the slab is heated, it retains the heat and lowers our overall energy bill. Also, I despise crawl spaces. Critters can get in, and bugs and then I have to crawl under there to maybe get stuck, and cobwebs, and...and.....and.... (I am such a wimp!)

My bro-in-law is building a cabinetry shop ( nice one too, commercial, three-phase...I am SO lucky!) and he went with in-floor heat. But, he went with added fiberglass instead of wire mesh to prevent cracking. Less expensive (overall) and much less likely for the concrete to crack. He is going with a bare concrete floor, although treated, to keep clean up easier. He will add padded areas where he will stand often.

Good luck, and a pre-welcome home!

[Frank Fusco]

This was true of the earlier systems that used very hot water. Today's hydronic systems use much more moderated heat, whether they are in-floor or not, and it's much more comfortable. There is less "pain" during seasonal transitions, too.

That's good to know. My experience "as a kid" was a long-long time ago.

[Mike Williams]

Let me know when you are back--I'm a little more than an hour south of Howell if you want to see what I did with my shop.

Matt - thanks for the invitation - it would be great to see your shop and talk with you. I look forward to the day when I can meet some of you all in person, rather than solely over the net!

[Mike Williams]

Hi Mike,
I built my 1560 sgft shop(hobbiest)from scratch and chose the in-slab radiant system...I think you should keep this at the top of your short list.

John - thanks for the information and the vote. I hear strong votes for the radiant heat, and strong votes for wooden floors - which is what I would have expected. But it doesn't look like there is a good way of marrying those together with a concrete base slab.

Seeing a compromise in my future, right now I"m investigating a low intensity gas infrared heater by Roberts Gordon - model is 'Caribe'. This is a ceiling hung unit designed for garages and workshops. I don't think it would be as nice as the floor heat, but is probably far cheaper to install that the floor system and doesn't have the air currents that forced air would have.

We love the Seattle area. I was stationed at the Naval Torpedo Station in Keyport on the Kitsap Pennisula in the early 70's. I left just before they announced the base would become the Pacific Trident submarine base. I asked for the Pacific Northwest again, so they sent me to Adak out in the Aleutian Islands. You've got to be careful what you ask for!

[Mike Williams]

First, hello fellow Michigander! Near Bay City here :)

I have my basement floor heated with tubes and hot water, and we love it...My bro-in-law is building a cabinetry shop ( nice one too, commercial, three-phase...I am SO lucky!) and he went with in-floor heat. But, he went with added fiberglass instead of wire mesh to prevent cracking...

Hi Bob - it will be great to get back to Michigan next year. I hear the suggestions of going with the concrete and then just using a lot of padded areas. To me, that just isn't as 'nice' as having a wood floor everywhere. Maybe I'm partially hung up on the aesthetics, but that's me!

At work, we've often used fiberglass reinforced concrete in slabs on grade and had good luck. I used them in the basement and garage in our last home, and also had a good experience. The only place I had a problem was along one exterior wall - a crack opened up. And that was a bad joint between the slab and the vertical wall / footing - not the slab itself.

[tod evans]

mike, after speaking out against radiant heat under a wood floor, i`d like to state that i`m a strong believer in concrete floors in a shop and radiant heat works very well with them....02 tod

[Mike Alagna]

I have radiant heat in my house and it is the type that was shown in the picture where it was mounted under the floor with the aluminum heat deflectors. What what I have experienced I would either go with the concrete slab and no wood so that youfeel the direct effects of the heat. I think you will lose the comfort effects of the wood being directly on the slab anyway, or I would go with a crawl space over a slab for moisture and cleanliness then a standard floor with the radiant under mounted. The tuping goes in after the floor is in so you can position all of your tools and run duct work under the flooring etc, then when it is all done you run the tubing so you don't have to worrk about damaging the tubing when running the electrical and ductwork. After the tubing is run and the system is tested you insulate (foil up) to force the heat up to the floor. If you ever want to re-run ducts or move equipment you can access the tubing. You will get the "bounce" benefit of the wood, the heat benefit of the radiant and the space benefit for the ductwork and electric by using the crawl space. And if for anyreason you drove a nail or screw through the floor and into the tubing you can always access it to make repairs.

[Chuck Trisdale]

I never have had to worry about heat. A little electric heater will do it for me - at least get it about 55 degrees in my uninsulated garage on most days.

Now summer on the other hand - Ugh. Fans, and just learn to live with the sweat.:mad:

[Jerry Strojny]

There is no reason you can't put wood over some or all of the floor. The calcualtions just need to be adjusted for the layer that will transfer the heat slower than exposed concrete. There will just be more tubing under those areas where the wood is. Someone already mentioned using a water heater for the heat source. This is a great way to save money (in lieu of a boiler). Now, I will agree that the upfront install cost of a radiant floor is more expensive than many other methods. But I also feel that radiant heat is the most comfortable, and may be the least on energy consumption in the long run. (With energy prices fluctuating so much, it's probably a "crap shoot".) So, I'm sure whatever you choose will be well thoughtout and liked when your done. And really, having "lots" of insulation is the best thing to do, no matter what type of system you decide to go with. You have that covered, so any choice is a good choice.

[Jeremy Gibson]

I have thought of a similar setup in my "dream" shop too - crawl space with wood floor or a wood floor over a slab. I had thought the WarmBoard brand product was the best way to get radient heat with a wood floor. I understand radiant is more expensive to run and supposedly cheaper to operate than other heat sources. One option is to install solar collectors to heat the water, or use a closed system with antifreeze added. This would again add to the initial costs, but if you get enough sunlight it should (theoretically) provide heat for free - minus the electrical cost of a pump.

[Joe Mioux]

Mike:

There has been a lot of good advice given in this thread.

From my experience, I have a couple of points that may help you make a decision.

First, Infrared heat is good for places such as warehouses. I don't think I would want to spend a lot of time standing in one place with that type of heat.

It is not necessarily comfortable.

If you need convincing, stick your head inside your oven when its on broil!

The Hot Dawg route is good for already built structures. ... retrofit... would be a good word.

I have a Reznor V3 t-core in my garage. It works great in a garage setting or a structure already built. In minutes I am comfortable.

So you have two options... Hot water heat or hot air.

With a hot air, furnace, you will gain the benefit of AC for not much more money.

Hot water heat in the floor is the Cadillac of heating systems with a seperate AC unit. Just ask any plumber (heating guy) they love hot water heat.

If you go furnace/AC, look into geothermal. Very very energy friendly.

Joe

[Mike Williams]

Mike: There has been a lot of good advice given in this thread...First, Infrared heat is good for places such as warehouses. I don't think I would want to spend a lot of time standing in one place with that type of heat.It is not necessarily comfortable. If you need convincing, stick your head inside your oven when its on broil!...

I love it! So maybe low intensity gas radiant heat along the ceiling isn't the best idea.

There's one other option we haven't discussed. What about electric ceiling panel radiant heat? Twenty years ago, I can't even imagine asking that question. But with an aggressively insulated and sealed building, it might be a good answer.

It would be clean. I think it would get rid of the broiler effect. An article in FWW 133 listed one fellow who had it in his shop (I think in the Northeast) who was happy with it. One of the suppliers markets panels specifically to the wood workshop market, which makes me think someone is buying them. The panels aren't cheap, but I don't think they would be as expensive as the hot water tube and boiler / water heater.

[John Bush]

Hi Mike,
Lots of great info but still too many choices.!
The initial cost of the radiant floor system isn't really that bad. I think I paid ~$700(1000 foot roll) for the tubing and just a couple of hundred more for the control/pump system and the hot water tank was maybe $400. I got the type that has the intake and exhaust air in the same pipe and eliminates the need for a roof pentration for the exhaust. If initial costs are a significant concern, I'd suggest that you place the tubing in the slab with the plan to install the rest of the system at a later time. With regard to the advantage of wood flooring, I think that a 7 to 5, 5 day a week job standing on the hard stuff would warrent the consideration of framing a conventional wood floor system, but if you are using your new shop for hobby fun, I think the slab is a much better way to go. Good luck. JCB.

[Peter Mc Mahon]

Hi Mike. This is what I have. I love it. Very efficient and quiet. Not at all like sticking your head in the oven. It cost me $800 Canadian. www.garageheater.com (http://www.garageheater.com)

[Mike Williams]

Hi Mike. This is what I have. I love it. Very efficient and quiet. Not at all like sticking your head in the oven. It cost me $800 Canadian. www.garageheater.com (http://www.garageheater.com)

Peter - thanks. That's the kind of low intensity gas radiant ceiling unit I was considering. I've challenged a vendor's rep back in Michigan with the 'head in the oven' comment. We'll see what he comes back with.