building a shop question

[Eduard Nemirovsky]

I am planning to build a WW shop on my backyard. It will be a 20x26 wood shed, I do planning to use isolation and put AC with heat (split system). It will be one man shop.
My question is about foundation. I have a three options:
1.just 6x6 on concrete blocks
2. slab concrete foundation
3. Concrete column(?) on a corners and in the middle.

Problem with pouring slab - area is not accessible by a track and concrete needs to be delivered by small portions.
Can you give me any recommendations? suggestions?
Ed.

[Thom Sturgill]

At 20x26 you will have to meet code requirements. I doubt that piers just at the corners and center would work with 2x6s - You probably would need a grid of 4 on the long side and three rows. Keep you longest spans under 10'. I am planning on 8' 2x6s 12" on center with spans no greater than 8' in order to get enough stiffness for the lathe, table saw, etc. You can use 6x8 treated (or rot resistant) wood posts sunk below the frost line. Use an auger to drill the holes and fill the bottom at least 4" with gravel then insert post and concrete. Cut them off level such that the bottom of the joists is no less than 12" above the ground at the lowesr point. Of course if local codes require a continuous footer this will not work, but you could pour the footer 12" deep and build the piers out of cement block.

[Roger Jensen]

Getting concrete back there is no problem. They'll use a pumper from the street. It added about $500 to my job, but it was great not to have trucks trying to get back there.

Just a warning - be prepared to be shocked at the price of concrete...

Roger

[Harvey Ghesser]

Hi Ed,

Good luck with your project. I had a garage built once and the concrete was brought in with a workforce with wheelbarrows. One after another. It worked fine. The cement slab is your best option.

Hope all is well!

Harvey

[David Hostetler]

At that size, a concrete slab is the way to go.

Not sure about the climate in Va. but radiant heat in the floor is something to consider if you are going to pour.

[Rob Russell]

+1 on the pumper.

We did a 32x24 addition on the back of our house. We have about 60' from the front of our garage down hill to the street (a good 6'+ drop). The pumper had to reach up and over the house to the backyard and reach all the way out to the forms, some of which were 24' out in back of the house. It looked like a huge praying mantis. Worked great. Just beware that they need to clean out the tube somewhere and you want to tell them where to dump the pipe clean out discharge.

I also agree that a heated slab with radiant heat would make that a most comfortable shop in the wintertime (help keep the machines dry, too).

[Dave Wagner]

Definately check local codes for "Slab on Grade" if you go that way.

Our local codes, I had to provide a "certified slab drawing" stamped by a PE.

I Didn't have to have a pic of the garage or anything, just the slab design and details of how and what was going to be built...

[Eduard Nemirovsky]

Thank you very much for your replays, look like a have an one choice - concrete slab.
I am not sure that pumper will be able to reach to my side - it is about 125-150 feet:eek:. Will talk to "concrete guy" about it.
David, you did mention "but radiant heat in the floor is something to consider if you are going to pour" - what is about? Would you please clarified for my:confused:.
Dave -thanks for "local code" reminder.

Ed.

[Tom Wassack]

Greetings from NC!
Eduard,
A foundation built shop is not out of the question! My 18X30 purpose built shop is on a pier and curtain-wall foundation. The joists are 2X8 SYP on 12 inch centers with piers supporting a center girder. The overall span of the joists are less than 9 feet. My justification for a foundation/floor system instead of concrete was comfort of the back and legs, minimal damage of a dropped tool, electrical, and dust collection under floor to the machines. Even with my floor system, I still have some heavy vintage industrial machines in use such as a Porter jointer, Powermatic planer, Unisaws, 16 inch radial arm saw, etc. In summary a concrete slab is not your only choice - simply one of preference.

Respectfully,
Tom Wassack
Asheboro, NC

[David Hostetler]

It's not relevant to my locale, but I see on the Home Improvement shows a lot of the slabs being poured up in the northern states get some kind of radiant heat tubes run through them. The idea is to keep the slab warm and in turn the interior space warm during winter months, and minimizing contraction of the slab... I guess reducing the possibility of cracking... Not sure. Just figure if you are going to do that, the time to do it is when you pour from what I have seen...

[Jason Strauss]

you did mention "but radiant heat in the floor is something to consider if you are going to pour" - what is about? Would you please clarified for my:confused:.


Ed.

When my In-Laws built a new house several years ago, they had radiant heat put in their poured basement and garage. Very nice, and efficient, too! The contractor used a PEX or similar material, snaking a single length of it around in a continuous pattern on top of the prepared sub-surface (gravel). The system was then pressure tested and hooked up to a very small gas boiler. The concrete was poured, and presto...dry, even heat in the basement. No need (or very little) to use the forced air system in the rest of the house. I believe that you can even tap off the boiler to use for running hot water if you want a sink in the shop, too. Something to think about...

[Eduard Nemirovsky]

OK, I got it. But I am not sure that radiant system will work in my setup. On a concrete slab will be 5/8 of plywood. Shed has own wood/plywood floor.
Or I am making it very complicated?:confused:I do have a small shed - I install concrete units and 6x6 for a base of the shed. May be I can do the same for a bigger shed?

Ed.

[Ken Fitzgerald]

Ed,

I built a 24'x30' shop 5 years ago. I wanted radiant heat so badly. Unfortunately to meet code, drove it out of range of my budget.

In the end, I went with 2x6 construction, R-19 in the walls and R-40 in the ceiling. The LOML gave me a 75,000 BTU Lennox gas furnace for Christmas. It's toasty and it doesn't cost an arm and a leg to heat.

While we see temperatures in the 100s here, it normally only lasts for a month or so. The insulation in my shop often keeps the temperature inside at least 18º lower than the outside temp in the heat of the summer. I can live with that.

Concrete foundation is the way to go. I have poured footing, wall and floor.

Good luck with your endeavors.

[Daryl Henderson]

If you are plywood deck over concrete, check out thermosoft.com.

I have their mesh under the tile in both baths and the pad under the hardwood floor (glue together).

It is easy to put down under tile or wood. It is electric powered and doesn't use much energy.

[Don Bullock]

...
Just a warning - be prepared to be shocked at the price of concrete...

Roger

I'll certainly agree with that statement!

Be sure to check all your building codes for your type of structure. You may also be required to supply plans certified by a structural engineer. It's amazing all the things that are now required in some areas.

In addition, check out permit costs. With the current economical situation most government entities are in these days the cost of doing business is rising dramatically in some areas. Permits and inspection costs alone for my 24' x 40' shop/garage were well over $5,000.

[Roger Jensen]

Be happy you don't live in California with us. You have the additional seismic requirements to tie down studs to the foundation and shear walls. Good for you in the long run, but it is an experience to implement.

Roger

[Chuck Isaacson]

Getting concrete back there is no problem. They'll use a pumper from the street. It added about $500 to my job, but it was great not to have trucks trying to get back there.

Just a warning - be prepared to be shocked at the price of concrete...

Roger

I can second that. I had to use a pump for my foundation because the weather turned the ground to crap so they couldn't get the truck out there. It was $500 plus the extra concrete to fill the lines. It adds a little bit but it would be worth it. When I did mine, I also put 2" of Styrofoam insulation underneath the slab along with a moisture barrier (required by code) in the area that I am heating. I would recommend this. I doesn't add that much and might save you in heating costs. One thing about the radiant heat is that it can be very expensive!!!. It would have cost me $10000 to put it in my 24x30ft shop. I ended up going with the Hot Dawg Heater from Modine. I am going to put it in this fall.

Chuck

[Scott T Smith]

Radiant heating is a great way to heat a shop, and there is a lot of information available on the internet about economical ways to do it yourself.

I installed it my 5,200 square foot shop for less than 10K. If you buy an "off the shelf" system, then 10K is not unreasonable.

You will need at least 2" of styrafoam insulation under the slab, and 4" is better, along with a moisture barrier. You will also want to insulate between the outside of the slab and grade so as to create a thermal break.

A concrete pumper should be able to make a 125 - 150 reach. If you want the highest quality concrete possible (and with minimal cracking), specify a low slump mix (3 - 4" maximum at the site) with a water reducing admixture for the pump. Also, if you can wait a couple of months to pour the foundation (after it starts cooling down but before it gets cold - such as early October), the slower curing time will ultimately result in a stronger slab.

There are plywood products available that have radiant heating tubes incorporated into them, in case you want to add it after the slab pour. If you do install it in the concrete and put 5/8" plywood on top, you will get the best thermal transfer if you glue your plywood to the slab using a high quality wood flooring mastic.

[Tracy Work]

We built a 30x50 shop last year and considered radiant heating (which we actually have in our house).

Obviously in CA we don't see the low temps that others here see. Nonetheless, I'd suggest you consider how often you'll actually be in the shop before going with the radiant heating (or perhaps just install the Pex and wait on the actual acquisition of the boiler). The problem is that it takes a bit of time to heat the fluid in tubes. If you only work in the shop on the weekends, it may not be cost effective to keep the shop heated all week and may not be effective to only turn it on during the weekend.

I did not run the Pex in my foundation. I have a friend with a similar size shop who did actually run the tubing, but has since never bought a boiler to use it. We both have gotten away with using used pellet stoves. They're relatively inexpensive and take the chill of pretty well.

Just a thought. Good luck!

Tracy

[Gary Lange]

I think if I could I would built it with a three foot deep crawl space so I could run my Dust Collection under the floor as well as have access to it and the electric. It would be nice to be able to get to the DC system and add to it plus not have tubing laying all over the floor.

[Curt Doles]

A few years ago, I had a drive extended to my workshop. The contractor used these powered wheelbarrows to avoid driving the loaded cement truck up the existing drive. I think two of these were able to stay ahead of the finishers with no problem. I believe they were 1/2 yard.

I'll take the driving job over the finishing job!

Curt