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Forum topic by AviatorDave posted 03-27-2012 04:56 AM 2047 views 0 times favorited 19 replies Add to Favorites Watch
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10 posts in 2287 days

03-27-2012 04:56 AM

Topic tags/keywords: workshop duct work running electrical heating air hose work space new workspace pole barn dream shop shop design question tip trick resource

Hey folks,

I have some thoughts to pose to you. I hope to be building a workshop in the next year or two and to fill the time with something other than just pining for the new space, I’m doing a lot of thinking about how to build it. It’s going to be built from the ground up so now is the time to brainstorm for neat ideas. I live on 10 acres and the basic plan is to build a 40’ x 60’ pole barn with a concrete floor. The whole barn will not be used for the shop. Some of the space will house the normal stuff one accumulates through life and can’t find room for. The barn itself will be uninsulated but the workshop portion will be insulated and heated. I haven’t looked into how tall the barn will be so I haven’t really thought about the ceiling of the workshop portion yet. What I’ve run across a couple of times from different people on different topics is the notion of building a false floor and running power under it as well as hot water pipes to heat the floor. This concept of a false floor could also possibly have benefits for exhausting paint fumes for a paint booth, running dust collection duct work and maybe even air hose plumbing. (Although I must admit that I prefer an air hose to be hanging above me on a spring to pull down when needed and retract up out of the way when not.)

The workshop will basically be a woodworking shop where my crop of woodworking tools may finally find a long term resting spot. This is to say no mobile bases. My thoughts before hearing about a false floor were the normal ones of having drops for everything. The thought of an uncluttered look with the false floor is appealing but in thinking a little more about it, I can foresee some problems with access to things in the event of problems or expansion/maintenance. I can’t even say that I’ve pictured what the floor would be made of but I picture it sitting on top of the concrete.

It may be that a false floor was a great idea for computer server rooms back in the 90’s and have no place in a wood shop . . . but since the project is still a ways off I figured that now is the time to dream and see if there are some good ideas out there.

So in summary:
Floor heat vs some other method?
Power under the floor vs drops?
Dust collection duct work under the floor vs drops?
Air hose plumbing under the floor vs up in the ceiling?
Paint booth ventilation as downdraft vs exhaust fan in the wall?
How would you build a floor like this that gave access and still supported the weight of heavy shop tools?

It all sounds very cool to me . . . but the engineer in me recognizes that form and function could be hindered by a poor fit and make it unpractical and possibly even unsafe if not set up right so the inclination is towards drops.

Do any of you have any experience with this? What would you do with your dream shop along these lines if you could? (or what would you not do?) All comments and advice are welcome on any or all topics!


-- Somewhere in this piece of wood is a finished project covered in sawdust.

19 replies so far

View Ben's profile


302 posts in 2355 days

#1 posted 03-27-2012 05:11 AM

I don’t know about a “false” floor, and don’t have any real experience with this, but I have seen and read a lot about having utilities in the floor. Most I’ve seen that were concrete floors had the ducting, conduit and tubing for radiant heat laid in before the concrete was poured. It would take some serious planning to have everything where you will want it permanently, but with a space as large as you are planning, layout would be fairly simple IMO.

-- Welcome to downtown Coolsville, Population: US! --Hogarth Hughes

View a1Jim's profile


117115 posts in 3602 days

#2 posted 03-27-2012 03:53 PM

Hi Dave
I have built my own shop an in fact I’m a contractor of 25 years. I wanted my shop ceilings high enough so I could stand 12’ material on end so I made them 14’ high,I like it that way but there are some things to consider,heating that much area takes a lot long in if your using a gas or any fuel you pay for it’s going to drive your heating cost up. If you are hanging things on the rafters(I hang most of my jigs there) you will need a tall ladder or use a long stick with a forked end on it to hang things up and take them down. I have most of the things your talking about in my concrete floor and it makes life a lot easier. You use the term false floor I’m quite sure what you mean about that, but your talking about building a floor over a floor that doesn’t make any sense to me. If you want all the things your talking about under your floor I would just build a wood floor with crawl space below it . That will make the the installation and maintenance of all of those systems much easier. Don’t be that concerned about weight if built in the correct way you should be able to park a truck on it. I believe you will need to have both in floor and ceiling drops for air,dust collection. I think radiant floor heating is the best way to go heat wise. I would make sure you have a space for your air compressor and dust collector out side for noise and safety considerations.If your thinking of building a spray booth you want to consider having fans blowing air in and fans blowing air out with filter systems and a concrete floor with a drain system for cleaning up.I think your very wise to give all these issues a lot of consideration before building .

-- wood crafting & woodworking classes

View Manitario's profile


2630 posts in 2908 days

#3 posted 03-27-2012 04:12 PM

If I could build my dream shop, I’d have in floor heat; quiet, efficient and no air movement to stir up dust. I’ve seen some LJ’s that have infloor electrical and DC, personally I wouldn’t like to lose the flexibility of being able to change my shop configuration.

-- Sometimes the creative process requires foul language. -- Charles Neil

View rkober's profile


137 posts in 2317 days

#4 posted 03-27-2012 05:54 PM

I couldn’t afford radiant heat in my shop when I built it but have it in my house now. It would be great in a shop. I would recommend a concrete slab either way (and not a false floor). Radiant heat in the slab requires some design considerations (including insulation underneath). The slab also acts as a thermal mass and is very efficient and comfortable. Consider freezing if it’s an issue (you can run antifreeze in the tubing).

Like Jim I have 14’ vaulted ceilings (at the eve) in my shop which I enjoy. We have part framed off that has a loft which now adds a lot of usable space.

Knowing what I know now, and related to your thoughts, consider running conduits to multiple locations for future use. You could pour hand holes into the slab with conduit drops to allow wiring machinery in the future.

Good luck. Someday I’d like to add a 40’x60’ to my shop and build it the way I want.

-- Ray - Spokane, WA - “Most people don’t recognize opportunity because it’s usually disguised as hard work.” - Unknown

View a1Jim's profile


117115 posts in 3602 days

#5 posted 03-27-2012 06:21 PM

A couple points ,If you have a wood floor and a crawl space you do have flexibility to move you power,dust collection air,etc. because you have a wood floor and can patch any holes you make for your air or DC. Another way to keep your layout flexible is to have elec. air,DC above and below the floor ,when I built my shop I put in a 200 amp service and ran 220 and 120 outlets ever 6ft around the whole perimeter and some optional places in the floor.
Another point is radiant heat does not have to be in a concrete floor it can be installed under a wood floor . Even though I have a concrete floor wood floors are much easier on your body over the years. I think a loft is a good idea,but if I did that I’d go with a 16’ ceiling height so you can stand upright while your up in the loft. Another item to plan for is storage for your material ,I find it taking over my shop and have not covered space outside due to my postage stamp sized lot.

-- wood crafting & woodworking classes

View ChuckC's profile


828 posts in 2960 days

#6 posted 03-27-2012 06:42 PM

Radiant heat in concrete takes a long time to heat up (maybe even under wood too??). It may not be the best way to go depending on how many hours a day or week you will be spending in there. I only get a few hours a week, on average, in the shop so it’s much cheaper for me to use a propane heater to just warm it up while I am out there.

View muleskinner's profile


896 posts in 2461 days

#7 posted 03-27-2012 09:18 PM

Myself, I’d prefer floor outlets for my stationary tools and a couple cord drops for portable tools. I like having my air overhead – the less stooping the better. Your heating configuration depends on what kind of heat. Most everything else I’d keep overhead because 1) there’s more room and 2) I’ve spent enough time in crawl spaces.

It’s going to be built from the ground up
That’s the way I’d do it too. :)

-- Visualize whirled peas

View Jim Finn's profile

Jim Finn

2657 posts in 2947 days

#8 posted 03-28-2012 12:56 AM

I have worked in computer rooms moving heavy equipment over “computer room floors” They are 24” square tiles supported at all four edges by a grid and just lift out to give access to the 9” or so space under the floor. The floor sets in this grid and is supported by, glued in place, vertical steel channels. An expensive floor for sure but maybe one could be made a bit less expensively. This would give you complete flexibility for exhaust, heat, electric power, compressed air etc.

-- Website is No PHD just a DD214 and a GED

View canadianchips's profile


2602 posts in 3022 days

#9 posted 03-28-2012 02:17 AM

My first shop was 50ft x 50ft, arch style rafter building. I had a loft across the back, on top of my woodworking area. I advise to put radiant heat in the floor. You can run a header and only heat part of the floor if you want. Adding as you need to. Just put the pipe in BEFORE.I cemented my floor in 3 sections (As I could afford it) I lived in Sask.Cdn. We had freezing temp. from Oct 31 to end of April ! #1: The secret to floor heat is never turn heat off in winter ! Even when I wasn’t in the shop I kept it just above freezing. When I needed it it DID NOT TAKE long to get floor to comfy temp. #2: you do not have to set thermostat at 70 degrees F. to be warm with in floor heat. A good working temp of floor heat was 55-60.
The second thing I had was PVC conduit in the floor to run electric to machines. I did not have my DUST collection in the floor. My thoughts were less plugging going overhead.
I also put 16”l x 4” d. pipe cemented into the floor , 2 rows every 10 ft. length of building .I made jigs that would fit inside these and could use them for roller stands, pulling autobody work or whatever. The one mistake I made. I only had 1 overhead door to allow vehicles in or out. In winter I had to open a 20ft. w x 15ft h door. I wished I had put 2 large doors in.
You are on right track thinking about WHAT you want before you do it. It is CHEAPER on PAPER to make the changes.
Best luck with your shop !

-- "My mission in life - make everyone smile !"

View AviatorDave's profile


10 posts in 2287 days

#10 posted 03-28-2012 04:43 AM

Wow! This is fantastic advice! Here’s a few more things to toss into the mix:

Since l live out in the styx, propane is the only gas source I can tap into. The house is heated and cooled via a geothermal heatpump and I’m pretty happy with it. To the extent that I’m considering putting the same thing in for the workshop. What are your opinions on how to provide the energy for the radiant floor? (seems like most people are in favor of a radiant floor) Circulated hot water or hot air? I’ve used to have a home with a boiler so I’m a little familiar with closed loop hot water systems but not sure about closing a loop for hot air. In theory they’re both fluids, I think water is probably more efficient at holding heat. I’m sure I could use a geothermal system to heat water . . . Just don’t know enough about it yet to know if that’s the right way to go. Also, it seems that putting the radiant system in and pouring concrete over it is the most talked about method . . . but I’m intrigued by the wood floor concept as well. I’m not all that jazzed about a crawl space but I agree with a1Jim that if it’s built right you should be able to park a truck over it. Thanks to Jim Finn as well for covering the floor over a floor concept. That’s exactly what I was thinking of. I don’t honestly know if that’s still used for computer rooms but it seemed like a great concept. Not really a crawl space but more of a floor that was really easy to take up to add/subtract/change layouts. I would not be excited about having to tackle a plugged DC line in a floor but if the DC components weren’t glued together and could be disassembled, a false floor would make it easier to get to. That said, If you have a false floor, that also means a lot of dead air space. How might that affect a radiant heat system? I picture a subfloor heating system still being a closed loop of some kind but this question speaks to whether the plumbing is encased in concrete or floating free under a false wood floor. Will I be losing out with heating dead air space vs warming up concrete or vice versa? Also, if I wind up with a tall ceiling, is this still trouble for heating the shop in that most of the heat will hang out at the top? I mean, I know the heat will rise no matter what but there’s a big difference in blowing hot air out into the shop airspace vs getting the heat from a warm floor. I suppose some ceiling fans would still fulfill the same purpose for pushing heat back down if this were an issue . . .

Hey canadianchips – Do you have any input on the cost of keeping the floor just above freezing in the winter and raising it while you’re in it? That seems like a good way to go . . . and that idea for putting in a header and being able to compartmentalize the floor into heating zones ROCKS!! I’m all about that idea!!

I think I’m sticking with my thoughts on having the air drops from the ceiling . . . for now . . . Seems silly to connect the hose at the floor just to string it up above me. I just like the though of having it up out of the way. Anybody have any arguments for coming up from the floor? Speaking of the ceiling, I like the idea of a 16+ ceiling with a loft but I’ve also been planning on having material racks at one end of the shop somewhere. (haven’t put together a floor plan yet) I too have been the victim of scraps taking over my shop. It gets annoying but darn it, it’s hard to throw out a perfectly good piece of wood!!

Thanks again for all the great input!! You folks are giving me lots to think about!

-- Somewhere in this piece of wood is a finished project covered in sawdust.

View a1Jim's profile


117115 posts in 3602 days

#11 posted 03-28-2012 05:35 AM

Sounds like a good plan using a geothermal heat pump. for your flooring. I think everyone talks about concrete for radiant because that’s what there familiar with. I’ve seen a number of folks who put it under hardwood floors including good old Norm,,357313,00.html As far as having over and under air and electric in my mind is no big deal. I like it because you don’t have cords or air hose under foot or hanging in your face. I have mine in the floor so it comes up right where my work tables and benches are along with long strips of plug ins on my benches and work tables I also have electric,air around the whole perimeter of my shop so if I change the layout I have power and air every where. I have a concert floor that I built what one might call gutters of small chases for my air ,power and DC it works fine but involved very good planing and I have a 1/4” steel plate on top so it can’t be removed for alterations. This also require very good concrete finishing. If you have a floor over a floor your wood floor will need to be around 6” or more to run you DC that’s going to require a lot of little braces or I beams of dimensional material that would need to be 12” . It’s something that can be done but could be challenging. Plus the aspect or dealing with in floor heating.

-- wood crafting & woodworking classes

View ChuckC's profile


828 posts in 2960 days

#12 posted 03-28-2012 06:33 PM

I think saying radiant heat takes a long time to heat up, or not, is relative to what a person thinks a long time is. I have radiant heat in concrete in my house and it can easily take a couple of hours to feel the floor get warm and the burner is running almost constantly while it’s doing it. For the little time I get to spend in the shop this would not be cost effective. If I was out there every day then maybe I would think different.

View mr500's profile


5 posts in 2275 days

#13 posted 03-28-2012 06:53 PM

Great Info

-- If you like your freedom..Thank a VET!!

View pintodeluxe's profile


5705 posts in 2838 days

#14 posted 03-28-2012 07:00 PM

I would go with a PTAC electric heat pump. Most affordable option for heating and cooling the shop. I don’t mind drop-down D.C. and electrical where needed. The things that worries me about in-floor DC is what if it clogs? Or what if you want to move it later? In a crawlspace floor it could work well.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View rkober's profile


137 posts in 2317 days

#15 posted 03-28-2012 07:49 PM

1) Typically water is used as it can carry more energy per volume (and steam much more than water!).

2) Radiant does not need to be in a slab and it doesn’t even need to be in the floor (however the floor is the most efficient). In a subfloor and stapled underneath, for example, you need to put insulation underneath to drive the heat up through the subfloor (which is an insulator of sorts).

3) I use a geothermal heat pump in my house coupled with radiant (slab and thin slab on the subfloors). It’s efficient and works great. However there are design considerations that make the system (and design) more complex. It’s not uncommon to see 400-500% efficiency (actually called coefficient of performance or COP).

4) FWIW when I fire up my heat in the fall I’d guess it takes several hours to warm the whole system up from 60 deg (?) to 70 deg. I would expect any slab to take an hour or two (even with an oversized boiler) to heat from 55 deg to 65-70 deg. With that being said, radiant is more comfortable at lower temperatures comparatively. You don’t waste as much heating the air in the ceiling and if you open an overhead door you don’t dump all the heat out.

Let me know if you need a mechanical engineer :)

-- Ray - Spokane, WA - “Most people don’t recognize opportunity because it’s usually disguised as hard work.” - Unknown

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