The Ultimate Shop Floor & Foundation: Costs, Ideas, Viewpoints, etc.

[Dev Emch]

This thread is to form a discusion on the ultimate shop floor. Its design, construction and costs. We are looking for ideas, problem solutions and of course, opinions on what is best. But opinions are just that... opinions. I too am considering a new shop building as I have almost outgrown what I have.

I just got through a belt of MINUS 30 degrees below zero weather and my bones are still thrawing out. So you know I have to go deep to get to the frost line. This eliminates the luxury of using a monolythic slap for a foundation and floor. I have to most likely pour a foundation. Then come back and afix the floor.

So my idea is to use those new styrofoam ICF blocks to build up the foundation form ontop of the footers. But I will wish to modify these. The footer will be wider on the inside to acommate poured & reienforced blocks along the inside wall to support heavy timber frames that span the floor. My floor beams are penciled in at about 4x10 beams on 16 in centers. The floors will be then be built up using 2x6 or 2x8 tonque and groove lumber. Two diagonals with one at -45 deg and the other at +45 degrees. Finally, I wll cover this with a 3/4 in hardwood floor. That may be wide pine, oak, hickory or maple.

The price of materials varies wildly. If you go to a home depot or other fancy lumber yard, be prepared to pay. If you can search the mom and pop network and scounge a bit, the costs come down quite fast. Reclaimed timbers and timbers cut from salvaged trees can reduce the costs massively. My new shop will most likely contains lots of old brick, rose red granite and beetle stain pondersosa pine. WHy? Because I can get this stuff around here much cheaper. Your area may vary. In an effort to make Denver a modern and clean city, the planers are more than happy to remove some of the old wazzee style brick warehouses. These were built using tons of kansas city red, water struck brick.

The last estimate I had for a new slab (25 feet by 50 feet) came to about $5000 to $6500 dollars. This does include labor. But I dont remember if this included the foundation materials and it does not include the concrete pump.

What makes the wooden floor nice is that you can inslulate it and run your DC and power cords up fron below. That clears lots of conduit and DC pipe in the overhead space. And you can take your time working the floor on your own.

The idea is not set in concrete but open for discussion and evolution. I know that Lou power nailed sleepers and flooring down on his slab. Many woodworkers like to have wooden floors. So if you going to have a wooden floor in the shop, how about getting rid of the concrete slab to begin with?

[tod evans]

dev, as uncomforatable as it may be i would not replace my concrete floor with wood. i slop glue and finish around,scoot machinery and just in general am much to hard on my shop floor to even consider hickory, let alone softwoods.....02, tod

[Chris Rosenberger]

Dev what are you going to be setting on your floor?
My shop floor joists are 2 x 10 yellow pine set 16" on center. The floor is 32' wide & split into 2 - 10' spans & 1 - 12' span. I screwed a 2 x 6 to the underside & in the center of each span the length of the building. The 2 support beams are made up of 8 2 x 8 yellow pine. The beams set on 16" x 16" columns spaced 10' on center. The floor is 2 layers of 3/4" OSB. I finished the top layer of OSB with 3 coats of polyurathane. I have parked my 3/4 ton extended cab, long bed, diesel pickup loaded with tools on the floor.

[Dan Racette]

I had my shop floor poured by a guy "doing it on the side" and it is 30 x 45 and it cost $3500 but the depth of pour escapes me at this moment. I believe it is 4in". That was for the guy to come in to a gravelled floor and frame out the forms, pour it, smooth it, and saw in relief lines. It included concrete.

In my industry (pre-press) false floors are commonplace and when I get rolling I will be putting one in. Basically a big torsion box floor, only on the "machine room" side of the shop. I will route the electrical, dust and possibly some in-floor heat. For now, I bounce from fatigue mat to fatigue mat. Hoses lie on the floor, and heat blows overhead. I had to get moving first.

dan

[Jamie Buxton]

Dev, I too like the idea of a shop floor you can get under. But if you do it that way, excavate far enough that you can really get under it without crawling around on your belly. Make it a real crawl space, where you can crawl on your hands and knees under every duct and beam. While you're down there, install a couple lights and power outlets. Doing it this way would mean that when you decide to move machines on the main floor, you can do the under-floor remodeling with less bad language.

[Jerry Olexa]

Dev, how long of a span for your floor joist? 4X10 are pretty hefty on 16" centers unless you have a long span (over 14-16'). I like your double and triple idea of flooring but you probably could get by with 2 layers esp if you're going to insulate underneath between the joist. Thats how I did my cabin (as it was built on 6x12 beams , 2X10 joist supported on concrete piers) and then sealed underneath w 1/4" ply. Your plan sounds good but you (like me ) are probably overkilling on your specs.

[Jamie Buxton]

Do I read you right that you're making the floor of two crossing layers of 2x lumber plus a layer of 3/4" plywood? If you're putting in all that lumber for load-bearing capacity, I'd bet that you'll get more stiffness with taller joists and a thinner floor, and spend less money.

[Andy Hoyt]

Do I read you right that you're making the floor of two crossing layers of 2x lumber plus a layer of 3/4" plywood? If you're putting in all that lumber for load-bearing capacity, I'd bet that you'll get more stiffness with taller joists and a thinner floor, and spend less money.
Spend $50 and have it engineered. Dev will have to know where all that heavy iron will permanently live, or overbuild the floor throughout the space to accoomodate the unscheduled yet inevitable rearrangement of the shop.

And I will second the nomination for access to the floor system from below. I've got about 6' of headroom down there in my barn. All my DC ducting goes down from each machine and then back up to the unit. It does require careful planning and an accurate drawing of the design if you're having someone else (eg Oneida) engineer the system and do the ductwork take-off, though. Works great, especially at clog time.

Note to self - don't push wet shavings into the floor sweep and use those zero clearance inserts more often.

[Phil Maddox]

In my "ultimate shop" the floor will be wood framed over an accessable crawlspace. I will have the space underneath to run electrical and dust collection with the advantage of being easily reconfigurable (yes that is a word).

The joists will be conventional 2x material with beams as needed to carry the heavy equipment.

The subfloor will be 2x6 to increase give more strength where machine legs sit.

The finished floor will be 3/4" plywood, screwed (no glue) only to the subfloor with PVC or vinyl tiles like they had in a recent issue of Fine Woodworking.


Good luck!

[James Boster]

Dev,
here goes my opinions and there just that my opinons. I would prefer to have an elevated wood floor if I was building agian and $ was not the big issue. I beleive you would be better off with a larger timber and one layer of 2x material. I currently have a concrete slab and have intentions of putting wood over someday. The type of floor I am planning is done by using hardwood blocks 4"x6" or so and around 4 or 5 inches long stood on end.:eek: Yes it takes a bunch of them! i worked in a plant one time that had this type of floor in there shops. Floors were probably put in in the 40's and were still in good shape. Just an idea, doesn't help with wiring or dust collection though. Whatever you do just don't go to cheap because it's a lot more expensive to redo. Good luck.;)

[Dan Larson]

So my idea is to use those new styrofoam ICF blocks to build up the foundation form ontop of the footers.

Dev, have you considered a precast foundation wall system? I like the idea of ICFs, but precast may offer some advantages to you. Having a crane show up and drop in your foundation one day, and then being able to start framing the next day could be a good thing when in an area with a short building season like yours. I know this idea goes against the usual Dev DIY/scrounger ethic,:D but it's something to consider anyway...

Dan

[lou sansone]

Hi dev
sounds like a decent idea. I actually thought about doing that with my buiding at one point. What I would have looked for is salvage material from old NE mills for the joists. There are lots of them around and at the time I think I was looking at 10 cents per bd foot. Now that was for joist material that was bretty boney. I have see folks use steel trusses and then deck it as well. I know that tod does not like the idea of the wooden floor, but all the old mills had them and they hold up fine. After a while they do get grungy looking, but so does cement. I like working on a wood floor. Some of the mills out here have "wood block" floors. look like wooden bricks with end grain showing. nice floors but hard to maintain.

lou

[Frank Pellow]

The floor of my shop (interior useable space 431 square feet) is built upon 13 concrete piers sunk below the frost line.

On those piers, are beams constructed by laminating three 2x8 pressure treated spruce boards.

On top of that are 2x8 spruce joists on 16 inch centres.

The floor is insulated with R21.5 rock wool and there is a 1/4 inch galvanized steel mesh under the insulation.

The floor itself is two layers of plywood, the bottom layer 3/4 inch pressure treated and the top layer 1/2 inch G1S fir. The floor has two coats of paint.

Because of this type of construction, the shop floor is at the same level as the deck which joins my house and shop.

All of this is described in detail with pictures in the thread: http://www.sawmillcreek.org/showthread.php?t=7769.

Here are the detailed costs:

1) Item: Subcontract drilling a construction of Concrete Piers -4 feet deep, 12 inch piers on 18 inch base with saddles set into the top.
Qty: 13
Price: $973 (Cdn)

2) Item: 5mil plastic to use under stone and as a vapour barrier
Qty: 1000 square feet
Price: $41 (Cdn)

3) Item: Crushed Stone -delivered
Qty: 5 cubic yards
Price: $286 (Cdn)

4) Item: Pressure treated spruce for floor beams (laminated three thick) and joists
Qty: 824 linear feet
Price: $1,279 (Cdn)

5) Item: 1/4 galvanized wire mesh to go under insulation in order to keep out critters
Qty: 460 square feet
Price: $486 (Cdn)

6) Item: Floor Insulation -Roxul rock wool Flexibatt R21.5 batts on 16" centres. Bundle does 40 square feet
Qty: 11 bundles.
Price: $241 (Cdn)

7) Item: 4' x 8' x 3/4" exterior pressure treated plywood
Qty: 16 sheets
Price: $942 (Cdn)

8) Item: 4' x 8' x 1/2" good one side fir plywood
Qty: 16 sheets
Price: $704 (Cdn)

9) Item: floor paint, oil based, two coats
Qty: 8 litres
Price: $69 (Cdn)

10) Item: Screws and nails
Price: $95 (Cdn)

11) Item: delivery
Qty: 1
Price: $45 (Cdn)

All prices include taxes. The total was for this part of my shop was $5,161 Canadian which works out to about $4,100 US at the average exchange rate in effect at the time I built the shop.

[Bart Leetch]

Well if I was to build a wood floor there would never be a vehicle i.e. truck or car on it. Although it would hold one if need be.

Beams made of 2x8 with 2x4 nailed flat on each side with edges flush with the bottom edge. The beam would be centered 4' apart & the end would set in a pocket in the foundation so the top would be flush with the sill plate and going from one end of the shop to the other would be supported every 4' by a 4x4 post with a concrete pad. Between the beams & between the beams & sill plate would be a 2x4 every 2' setting on the 2x4 that is on the side of the 2x8 that would be covered with 1 1/4" plywood & it could be covered with what ever wood flooring that is desired.

Now you can go into any kind of overkill you want but this floor will hold anything the average home shop would ever have in it. It would most likely hold even your heavy duty equipment. I've seen 2 2x12 thrown on top to protect it & 9200 lbs of small dozer driven onto it. Yes I know the 2x12 spread the weight of the dozer out. but I'm pretty sure that shop equipment wouldn't be to heavy for it.

This is the floor system my father built for many of the houses he built. Some had car decking most had 1 1/4" tongue & groove plywood.

[Christopher Stahl]

I think you should look into hydronic radiant floor heating especially with those cold temperatures. This would make for a comfortable workshop.

chris

[Dev Emch]

Boy, there are some good ideas floating about here. And I forgot about DUTCH TILE. The shop space at Wright Patterson Air Force base was done in dutch tile. Not sure how deep these went. Dutch tile has end grain showing on 4x4 to 8x8 timbers. Then they often used some kind of cork based grout to fill in between the timbers and the floor was oiled. You often saw this floor in old machine shops. But metal machines such as planers and jig bores were often set into the foundation and grouted in with cement. Its a cool floor.

But I kinda like the distressed form of normal wooden flooring. Tod's suggestion about glue is one issue one needs to consider.

In regard to radiant floor heating. Is there a way to obtain radiant floor heat using conventional type wood framing? I was always under the impression that you needed the gypcrete substrate to make this idea really shine. This creates a conflict between true hardwood flooring and true comfort. If possible, I would like to have both. So what products are out there can help one to install radiant floor heat. This would be nice for both the shop and the house! Then I can toss out those furry house shoes.:eek:

[Chris Mann]

Radiant heat can be installed under a wood floor. Depending on the wood you use for your floor you can run into problems if you don't slowly ramp up/down the heat at the beginning/end of the heating cycle. I also don't think it's as efficient as installing in a slab because you don't have the thermal mass to retain the heat. This is one company that will design the system and you can install it yourself:
http://www.radiantec.com/

When I redid my basement (underpinned foundation, dropped floor 3 feet), we put radiant heat in the slab. It was a no-brainer. And after two winters of use, it's great. yeah the concrete is a little hard on the feet/tools, but I just use the anti-fatigue mats and keep a pair of good shoes on.

[tod evans]

dev, along the same lines as radiant heat......it`s possible to use a dual-fuel boiler outdoors (insurance) and use radiators. either freestanding or baseboard variety. only food for thought. tod

[Christopher Stahl]

You can still install the Radiant flooring in the slab and then lay a wood flooring on top of it. You wouldn't be able to use a false floor, but you can certainly install the wood floor on the concrete. You can run into problems with cupping with real wood, depends on how hot you run the water. If you use an engineered wood flooring, you won't run into these problems.

Like the other Chris said, use anti-fatgiue mats and you'll be fine. I still believe this is the way to go if you want to be comfortable in the winter. There is another advantage to the radiant floor heating, less problems with humidity. It won't be dry in the winter since you won't have a heat source that eats your humidity. Much easier on the wood, equipement and your breathing.

chris

[Rob Russell]

For the folks who are talking about 1 1/2" thick dimensional lumber on its side, I'd check with an engineer to see if 2 layers of 3/4" ply would be stronger. If you're talking about a total of 3 layers of 3/4" ply (2 being the "subfloor"), I wouldn't be surprised if the plywood is stronger than the 2x subfloor with a layer of plywood.