Pole barn concrete floor question.

[wingrider02]

Hello All,

My pole barn is getting close to completion. For reference, I am building a 40x56’ with 12’ceiling. I plan to put 5” concrete over plastic, foam, and pex tubing. My base is 4-5” of class 5 gravel, and below that is clay seemingly down to the core of the earth.

I had a neighbor stop by that does concrete, and he offered a bid to do the slab, finished with saw cuts. It would be reinforced concrete. Quoted 8K for all.

I had asked about rebar, and his response poses my question. He stated that the reinforcement in the concrete takes the place of the rebar.

Does that sound correct? The only things I know about concrete is it gets hard, and cracks.

I will include a picture of where the progress is.

Thanks for any help!

 

[jedeyeben]

Yes if the concrete has fiber in it.


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[wingrider02]

Thank you for the clarification.

Guess while we are on the general subject, the foam underneath the slab...I have seen articles saying ridged EPS is better (and cheaper) than XPS. I wish to do this right the first time, so any advice on which to use?

 

[lakeroadster]

Opinions vary.

How confident are you that the sub grade was compacted correctly?

What will you be using the barn for.. specifically what weight objects?

If your not confident about compaction and / or are planning on construction equipment and items as heavy as that.. you should look into re-bar

If it is to be used for over the road cars and trucks and you're confident about the compaction I'd suggest that in addition to fiber mesh that 6 x 6-W2.9 x W2.9 wire mesh sheets (not rolled wire mesh) also be used, and that it be supported by 2" tall concrete dobies.

That way if you do get any cracking the mesh will hold the concrete sections aligned and won't allow for the cracks to turn into steps.

Some photo's for you of correct wire mesh placement... more information in my build thread below, go to post #124 on page 7.... https://talk.classicparts.com/threads/lakeroadsters-high-country-barn.22110/page-7

 

[joe_padavano]

I assume you're planning a floating slab. I've done several of these in pole buildings on the farm. The trick to prevent frost heaves is to ensure that the gravel under the slab is well drained so there is no water to freeze. I've run a network of perforated drain pipes in the gravel, routed to daylight. No frost heaves in 15 years.

 

[Leaflessshadetree]

IMO Fiber is good but it does not take the place of rebar, it serves a different purpose.
Wire mesh serves the same purpose as rebar, but isn't as strong (and there are different strengths of wire mesh).
For most driveways or garage floors wire mesh is fine and I'd want the fiber as well.

 

[86turbodsl]

My 4" floor has had fiber only in it for 16 years and no cracks anywhere. I'd say it works just fine.

 

[wingrider02]

I assume you're planning a floating slab. I've done several of these in pole buildings on the farm. The trick to prevent frost heaves is to ensure that the gravel under the slab is well drained so there is no water to freeze. I've run a network of perforated drain pipes in the gravel, routed to daylight. No frost heaves in 15 years.

I had wondered if using something akin to drain tile would be good to bury on the gravel. If so, this might be a good thing to plan before the rest of the fill comes in.

 

[seanc_mt]

Rebars cheap. Why skimp on the ONE thing thats the most permanent part of a build...

My slab has rebar and fiber.

 

[wingrider02]

I am certainly not trying to get out of it, just don’t know enough to make a decision on my own...also didn’t want to trust one persons word that drives up out of the blue and gives a quote.

As to what may be in this shop at some point, I will have a couple old and newer farm tractors in it, a variety of motorcycles, tools, and will be building a wooden boat. Down the line, we may find an old semi tractor finds it's way in there. Early on, will be everything from our house, as we will be living in this for a few months while the house is built.

 

[ConCretin]

Fiber mesh and steel reinforcing have different purposes. Fiber reduces the chance of early age shrinkage cracks but doesn’t do much once the crack forms. Steel reinforcing won’t prevent cracks but it will hold them together once they form.

A fiber reinforced slab with properly spaced control joints is typically fine. Cracks occur at the bottom of the sawcuts but as long as there are enough of them, the cracks are very narrow and aggregate interlock is enough to keep them from displacing.

Some of us are more comfortable with rebar or wire to provide some added insurance but you are likely fine without it. Many millions of square feet of slabs are placed this way every year.

If you decide to use steel, Lakeroadster has one of the best installations you’ll see. Give the thread in my signature line a read for more info.

EPS is usually cheaper and is absolutely fine. Just make sure it’s rated for under slab use. Look for a material complying with ASTM C578.

 

[wingrider02]

Thank you very much everyone! You have all been a great help!

 

[jdeshong]

I just had concrete poured in my pole barn 4" thick with 5.5" around edge of perimeter. Fiber mesh was used with no rebar. I'm in FL so no worries about frost heave, it came out to $3.25 per sq ft after some negotiation which is a pretty good deal around here. I did all the grading and compaction myself so they had it pretty easy.

 

[matt_i]

If the fibermesh took the place of the rebar...then wouldn't rebar be rendered obsolete?

I used #4 rebar, 16" on center in a 6" slab. Plans for heavy machinery and forklift rigging drove this prep.

 

[Modoc]

I used rebar in my pole building. I placed it on 2'x2' centers using the "Hercules" chairs. I have "Foamular 250 insulation under it with 1/2" Pex on 12" centers.

 

[MagKarl]

Fiber and rebar are both pretty inexpensive. No reason you can't use both, I did.