Concrete footer for storage barn?

[jjscott]

I'm getting ready to have a storage barn built in my backyard and have a few questions. The barn will either be 12x18 or 14x20...still debating between the two sizes. Either size will have a 7/12 roof pitch and 7ft side walls.

I am having a concrete floor poured and the barn walls will be anchored to the concrete floor. There will be no wooden floor with the standard 4x4's underneath...just the concrete floor.

The barn will be used for storing my mower, and other lawn equipment like walk behind leaf blower, wheel barrow, snow blower, power washer, patio furniture and the like.

My question is: do you think I should have a concrete footer poured? The county building department says it is not required, but I'm wondering if I should have it done anyway to prevent any type of cracking or heaving. Note that I live in northeast Ohio and have to deal with the freeze and thaw cycles.

Any other considerations I should be aware of?

Thanks

 

[NUTTSGT]

I'd share your concern if I were to do the same. There have been guys here that live in Michigan and done a monolithic slab for their garage. That would be less concrete than a true footer but more than a simple slab.

If no footer, maybe use some rebar to make sure the concrete is tied together and moves together if it does heave. Unless you can buy it at a concrete facility, Menard's has it fairly cheap for 20' pieces.

 

[jjscott]

They are pouring a 4 inch slab with the wire screen in the center to help tie it together. Pretty much like a driveway. Just not sure if a footer will be overkill. I know it will be more expensive.

 

[dbabicky]

Footer is not needed. Pour an 8"x10" grade beam with 2 rods in the beam around the perimeter with your 4" slab on the rest of it. You'll be perfectly fine. We do it all the time up here in NE Wisconsin. Never a problem.

 

[matt_i]

I would make sure you get rid of organic material like grass and topsoil in the grade prep.

I would do steel reinforcing, if you did ever get any cracking it will keep them tightly knitted instead of allowing them to walk apart. Much easier on the framing.

A vapor barrier would also help, a layer of compacted crushed, washed limestone would also be preferable.

 

[Mr Ratchet]

I've built around a dozen or so sheds/garages. I pour a standard slab usually with the fiber added and crushed stone. I take a flat shovel and go around the inside edge and remove an additional 2 to 4 inches. The oldest shed I built is pushing 30 years old at my parents house and everything is looking sound.

Go with the bigger one. I've never heard anyone tell me they wish they went with a smaller one. Quite a few time the other way around though.

 

[kbs2244]

You have a somewhat small and light duty project.

If you hire a good concrete guy he will give you a slab that will work.

 

[killahog]

Footer is not needed. Pour an 8"x10" grade beam with 2 rods in the beam around the perimeter with your 4" slab on the rest of it. You'll be perfectly fine. We do it all the time up here in NE Wisconsin. Never a problem.

I am contemplating a similer project , what is a Grade Beam?

 

[James-W]

My opinion is that for what you want, a footer isn't necessary. However, for a building that small pouring a footer won't add that much extra cost. It certainly would not hurt to have a footer and if it were mine, I would have a stem wall as well. I think if you were to do this, in the long term you would be happier with your storage barn.

 

[ConCretin]

In this case, footer or grade beam are just ways of referring to a thickened edge, which would be more than adequate for a small shed. A 6 or 8 inch haunch around the perimeter with a bar or two would be pretty easy to do and would help hold things together.

 

[dbabicky]

I am contemplating a similer project , what is a Grade Beam?

A "Grade Beam" is an 8 inch deep by 10 inch wide "Trench" around the perimeter of the slab filled with concrete and two rods all the way around. Then you pour the rest of the slab at your 4 inch depth.

 

[ConCretin]

A "Grade Beam" is an 8 inch deep by 10 inch wide "Trench" around the perimeter of the slab filled with concrete and two rods all the way around. Then you pour the rest of the slab at your 4 inch depth.

It's funny how terminology varies around the country. Up here a grade beam is a concrete element that is placed on grade but spans between supports, usually pile caps. It resembles a foundation wall but has no footing and is reinforced with heavy bars top and bottom with stirrups down the length just like any other concrete beam. Not really sure why any of that is relevant but thought it might be interesting for some.

 

[killahog]

Thanks

 

[ynned]

I've done both large and small concrete around here for 40 years. If you want a floor that won't crack and heave leaving uneven cracks an inch or more high, strip off the topsoil or sod, fill it back to grade with compacted stone, and pour footers. For a small pour like yours, I'd just pour it monolithically. You could probably get by with just thickening the edges a foot or so deep, but for all the extra it'd cost, I'd go at least two. If you just lay four inches of concrete on the ground, it's guaranteed to break up with the freeze thaw cycle. And if you're way NE like I am, you're probably building on damp clay to boot.

 

[bottom feeder]

I built a 12' x 14' garden shed in my backyard pretty much exactly as the OP described. I pored a 4" (probably closer to 3 1/2") slab with a thickened edge (I believe it was about 6-8" thick by about a square-mouthed shovel width wide). During the pour we inserted "J" bolts on the outside edge to enable the shed to be bolted down. The cement was pored directly onto the native (clay) soil. Because it was relatively small all necessary excavation was done by hand with a shovel. The shed itself was built like you'd build a house - stick framed 16" on center, etc. It has 8' walls and a 4/12 roof.

I live at 5,000' elevation in Utah so we definitely see freeze-thaw cycles. It's been there for 21 years with absolutely no problems. We put one control joint in the slab bisecting it in half. The slab eventually cracked right along the control joint, but you really can't tell unless you're standing outside the building looking at the outside vertical edge and the two slab pieces have never heaved. If I had it to do over again I'd probably put some rebar or mesh in as insurance against the slab heaving.

 

[RVDan]

How about a floating slab? http://floatingslab.com/floating_slab.html

 

[rburke65]

I need a slab under my existing 10’x14’ shed here in NE Ohio....this might be an option for me. I just have to move the shed!

 

[jjscott]

Thanks for all the feedback. Is it necessary to put down a vapor barrier for a project this size? 12x18 or 14x20 ft.

 

[finn]

How about a floating slab? http://floatingslab.com/floating_slab.html

That’s what others call a thickens slab or a monolithic pour.

Same concept

 

[brownbagg]

yes
pour a footer

 

[ConCretin]

Thanks for all the feedback. Is it necessary to put down a vapor barrier for a project this size? 12x18 or 14x20 ft.

Not absolutely necessary but it's always a good idea to limit moisture intrusion into interior spaces and it costs very little. No reason not to.