PDA

View Full Version : Shop floor: Wood or concrete



Andy Pratt
03-28-2008, 1:28 PM
As I continue my pipe dream shop-planning for next year, I'm re-examining my plans for the floor material.

My original thought was a concrete slab with hardwood flooring on top of it in the hand tool area. The more I read, the more it seems that I could probably get what I want in a wood-only floor over a crawl space. The cost would likely be less for a solid wood floor than the slab I would put in, and a contractor friend could save me a lot on labor here, and none if I do concrete.

Anyone with a wooden floor in their machine area have any comments here? I'm worried about floor sagging, how much overkill I need to make to avoid it and whether or not it is worth it to pay an architect or engineer to have a role in this.

The shop will be a 30X30 square with H20 radiant floor heat, insulation is key as I'll be in the NE, if any of this affects your advice.

Thanks,
Andy

BTW, the grizzly website shop planner is an awesome tool, spent about 6 hours on it yesterday moving pieces around, lots of fun.

Jim Becker
03-28-2008, 1:30 PM
Here's another thread on this very subject that started up just a couple days ago...

http://www.sawmillcreek.org/showthread.php?t=80428

------

A properly constructed wood floor is not going to sag. Remember, the weight from an individual tool is spread out a little and as long as you have the right design for overall load bearing taken into account, you'll have a very nice result. Concrete is "easy"; a bit more work for wood, but I'd have it if I had the choice, no question.

Chris Padilla
03-28-2008, 1:53 PM
Shooting from the hip, I would say concrete is a better way to get the radiant floor heat to work the best but with the recent realization of concrete rising is price quite a bit lately, I think a crawl-space with wood floor would be better.

As long as you are careful to pay attention to proper and sound insulation techniques (i.e. spray foam insulation), I think the wood floor would be much better on your feet, on your tools, and perhaps on your budget! PLUS, you can give yourself adequate access from underneath for any myriad of future issues and changes you are likely to encounter over the years. Make the crawl space as deep as you can handle...the deeper, the easier it'll be to work under there. Make the access door a rectangle and not a square in case you need to drag long pipes under there...you won't have to chop them up and then reconnect them underneath. I recently redid some HVAC pipe under my house...had to drag 2' sections down there and connect them up. PITA. :)

Good Luck!

Larry Browning
03-28-2008, 2:18 PM
I have a 30X42 shop with a crawl space and radiant floor heat. I absolutely love it. I am not sure where you live, but I live in west central Arkansas where we have pretty mild winters. I keep the shop at about 58 degrees a winter and my propane fired water heater cost me about $350 for the entire
season. I don't think that is too bad for 5 months of heating 1260 sf of space. I am able to move around my floor plugs and DC ducting fairly easily and it is much more comfortable walking around on it. The is a center support beam running lengthwise down the center of the shop. I have tied to place my heaviest equipment on top of that. I have my 8" jointer off of that but I added some extra support directly under it. I have had my shop for 5 years (I think) and have had zero issues with sagging. I would do it again in a heart beat.
A couple of other advantages. Since there is a crawl space, the shop floor is well above ground level. I built a porch/deck/loading dock which is about 2 inches below my tailgate of my pickup. This makes loading and unloading from th pick a breeze. The other thing is that I will never be tempted to drive a vehicle into my shop for any reason, making it a WOODWORKING only shop.

Ben Cadotte
03-28-2008, 2:22 PM
I would absolutely say if you don't need the space for a vehicle ever. The wood floor is the way to go. If your worried about sagging floor, just add a couple extra supports for the joists. And if you do, do the floor radiant, the floor will be a bit stifer as basically it will have 2 layers of 3/4" ply. And with several inches of insulation below the floor, your heating bill will be lower than a slab on 1" or 2" of foam board.

Your knee's and dropped tools will also thank you!

Ken Harrod
03-28-2008, 10:55 PM
The crawl space would give you space to run your ducting for your dust collection system. It would free up overhead and wall space for other items that way. Should help keep give the shop a less cluttered look.

Andy Pratt
03-28-2008, 11:33 PM
Thanks for the input guys, looks like it's going to be a wood floor unless something major changes.

If I do 1/2 the span for whatever normal home construction is for joists I imagine that would be more than enough. Would this be overkill or is it about right?

Andy

Larry Browning
03-29-2008, 8:40 AM
andy,
When I was planning mine, I found a website that allowed me to calculate the proper joist size and span etc. I don't remember what is was, but I'd bet a google search would find it.
<Edit.>
I did a google search on floor joist design and got several hits. the 1st one on the list is the American Wood Council (http://www.awc.org/technical/spantables/tutorial.htm) which could be just what you are looking for.
Unfortunely I did not find sites like this until after the builder had already built the floor using 2x8s. I found that he should have used 2x10s. But even with that I have not had any sagging problems. I just make sure my heavy tools are supported from underneath.
Also, I used radiant floor company for my heating system. They are really geared for the DYI guy. They will help you with the design and installation. good people to work with.

Ben Cadotte
03-29-2008, 10:42 AM
Thanks for the input guys, looks like it's going to be a wood floor unless something major changes.

If I do 1/2 the span for whatever normal home construction is for joists I imagine that would be more than enough. Would this be overkill or is it about right?

Andy

I just did a quick and dirty calculation. 2x10 SPF @ 24" o.c. are good for a 10' span with L/360 deflection limit, 10# dead load and 100# live load per sqft. L/360 deflection at 10' would be 1/3" (ie at max load on the joist it would deflect down 1/3"). L/360 is standard for living areas in a house. Dead load is the weight of the floor itself. Live load is what you put on top of it (you, tools, etc.) For normal const 2x10 for houses they are normally good to 14' (40# live load).

Using same formula / limits 2x8 in spf would give you 8' span.