pole barn concrete slab

[varmint]

In my 40+ years of doing architectural work, I've always figured concrete control joints at no more than 20' x 20'- the concrete shrinks, and you want the shrinkage cracks located where you want them, on the control joints- not here and there. The advice about rebar, fiber, etc. seems right on. The only reason to put some joint material at the poles is so the shrinking conc. can pull cleanly away. And, my last advice would be to use an epoxy finish on your slab. You want to do it before getting oil and crude on a new slab, after it cures and you acid wash it, and you'll love how junk cleans up for years afterwards!

 

[CurlyDave]

If you do decide to separate the slab from the poles, don't box them, wrap the poles with foam plastic or expansion joint material, or some other flexible material that will leave a round hole in a slab.

Most cracks in concrete start at a corner--make your holes round.

 

[timswi]

My pole building is 30x48 built in 2003. Poured one solid slab 5" thick with expansion felt against the poles. Then it was saw cut in 10/12 foot sections. No rebar or mesh. Just fiber in the concrete. No cracks or anything. In SW PA we get alot of frost heave, and I've never had a problem...Just pour it.

 

[hcallaway]

5" 3500 with fibers. Wet cut into 16 x 20 sections. I should know in the next year if it worked.

 

[whistlepig]

I have two pole barns. One poured 15 years ago and one poured three years ago. Both floors were poured around the poles. The poles were set on a concrete pad. I see no issues with pouring around the poles. Fiber mesh is nothing. Nobody but uninformed homeowners will buy it. I see a lot of industrial concrete poured for equipment that weighs many tons. The don't use fiber mesh. They use rebar. The last pole barn I had poured we drilled holes through the poles, ran the rebar through the holes, and then poured the concrete over it. This is the method I prefer.

 

[mlitt12345]

Here is my 30' x 50' pole barn slab. poured right around the posts no problems what so ever. Had them put mesh with fiber 5" pour and expansion joints.

 

[whistlepig]

Mesh will help. Not as good as rebar. Expansion joints give a hidden place for the concrete to crack. And the concrete will crack. I didn't do expansion joints. The expansion joints are much worse to deal with in the floor than the cracks over time.

 

[buckeyefarmer]

I will go with rebar. my earlier price was wrong, it's $.36 /ft. I'm going to pour to the posts. I'm waiting for the finisher to get back with regard to the cutting, to make sure he included it in his price. Hope to get it done in a week or so.

How often should chairs be placed under the rebar?

 

[Duffster]

I will go with rebar. my earlier price was wrong, it's $.36 /ft. I'm going to pour to the posts. I'm waiting for the finisher to get back with regard to the cutting, to make sure he included it in his price. Hope to get it done in a week or so.

How often should chairs be placed under the rebar?

I put them every 4' and I use the plastic ones like these.

 

[buckeyefarmer]

I'm having trouble locating plastic 3" rebar chairs. the local concrete supplier / brickyard only has 3" in metal, and they are expensive, over $1 each compared to about $.12 for 2" plastic chairs.