Concrete floor in pole barn

[Mac25]

I have just built a new pole barn and I am trying to gather some info about having the concrete poured. First off, the bottom skirt board is sitting 1-2" above grade right now and I plan to excavate around 10" to allow for a good gravel fill of 5" and about 5" of concrete. How do I keep the skirt board from bowing out as the concrete is being poured?

 

[s219]

Here's what I did, see photo in post #33 on this page:

http://www.tractorbynet.com/forums/...ole-barn-project-post3791388.html#post3791388

 

[wmonroe]

I had mine poured about a year and a half after the building was finished to allow for any settling. Like you I had about 5" of stone and then went 5.5-6" of concrete. I didn't do anything to the skirt boards, some had already been back filled with stone outside and some were exposed. I did not have any bowing once the concrete was placed, my skirt boards are treated 2x10's and the posts are about 8' on center. Here is a picture of my floor right after they sprayed the sealer on it, wish it was that clean right now.

 

[Mac25]

I had mine poured about a year and a half after the building was finished to allow for any settling. Like you I had about 5" of stone and then went 5.5-6" of concrete. I didn't do anything to the skirt boards, some had already been back filled with stone outside and some were exposed. I did not have any bowing once the concrete was placed, my skirt boards are treated 2x10's and the posts are about 8' on center. Here is a picture of my floor right after they sprayed the sealer on it, wish it was that clean right now.

How did you keep the gravel from running out of the bottom of the skirt board or gravel running inside if you back filled the outside? Trying to figure out if I should back fill the outside first or cut down the sod on the inside first.

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[s219]

Don't backfill against the skirts from the outside more than 1" or so, as they are generally not ground rated lumber (rare that 2x lumber would be). In my case, I had to add additional skirts on the low side of the building to close off the gap below the main skirt. I then raked fill/gravel just up to the bottom edge of the skirts on the outside.

 

[Mac25]

Don't backfill against the skirts from the outside more than 1" or so, as they are generally not ground rated lumber (rare that 2x lumber would be). In my case, I had to add additional skirts on the low side of the building to close off the gap below the main skirt. I then raked fill/gravel just up to the bottom edge of the skirts on the outside.

What lumber did you add that was ground rated?

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[wmonroe]

How did you keep the gravel from running out of the bottom of the skirt board or gravel running inside if you back filled the outside? Trying to figure out if I should back fill the outside first or cut down the sod on the inside first. Sent from my iPhone using TractorByNet

I placed gravel inside first at close to the level that would be needed for the floor. As I was adding the gravel some did go under the skirt board and end up outside but I didn't really worry about it since I also back filled all around the building with stone also. Like was mentioned most pressure treated wood is not rated for ground contact which is why I went with the gravel, so the water can drain away. One thing I've noticed recently is that as the stone packs and settles it leaves the skirt board exposed to the sun which I think is harder on it than being in the ground, I need to add another inch or two of stone to cover it.

 

[s219]

What lumber did you add that was ground rated?

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I used standard 2x8 lumber, not ground rated.

 

[s219]

One thing I've noticed recently is that as the stone packs and settles it leaves the skirt board exposed to the sun which I think is harder on it than being in the ground, I need to add another inch or two of stone to cover it.

I wouldn't worry about that too much. In fact, you definitely want to make sure as much of the skirt as possible is not in ground contact. Not only is that better for the lumber, it also means you have more "gap" to the siding material, which is generally a lot more vulnerable.

The real problem for lumber is intermittent wet/dry conditions, or cases where moisture can collect or get trapped periodically.

 

[wmonroe]

I wouldn't worry about that too much. In fact, you definitely want to make sure as much of the skirt as possible is not in ground contact. Not only is that better for the lumber, it also means you have more "gap" to the siding material, which is generally a lot more vulnerable. The real problem for lumber is intermittent wet/dry conditions, or cases where moisture can collect or get trapped periodically.

On my building the skirt board is only in contact with gravel, no soil. I'm just thinking about adding more gravel to keep the sun from hitting it.

 

[Tractor Seabee]

The building code states 8" between the ground and any non-ground contact decay able building material. When you get caught on this big time is during an inspection relative to a sale. I made that a repair condition in an offer, seller balked until 3 offers later and they all came in with the same. Seller begged me to honor my old offer. Told him no, you are now stuck with it. I had found something else.

Ron

 

[s219]

The building code states 8" between the ground and any non-ground contact decay able building material. When you get caught on this big time is during an inspection relative to a sale. I made that a repair condition in an offer, seller balked until 3 offers later and they all came in with the same. Seller begged me to honor my old offer. Told him no, you are now stuck with it. I had found something else.

Ron

It's not quite that simple. If it's floor joists in a crawl, the rule is clearance of less than 18" requires an approved protected lumber ** (see list below). If beams in a crawl, 12". If wood siding/sheathing, 6". Framing members that rest on concrete/masonry, 8". And sills/sleepers on concrete/masonry only need a moisture barrier. I don't believe there is a category that covers skirt boards on a pole barn, and that aspect of the barn is likely not covered by code anyhow (or it would be the inspector's call). Note in the types of lumber below that there are numerous categories that are acceptable to code that are not ground-contact rated (only C4 is ground contact rated). So anyhow, you don't necessarily need it to be ground contact rated, and the 8" number is specific to framing resting on concrete/masonry.

** Approved lumber is one that is pressure treated in accordance with AWPA C1, C2, C3, C4, C9, C15, C18, C22, C23, C24, C28, C31, C33, P1, P2 and P3, or decay-resistant heartwood of redwood, black locust, or cedars.

The only thing I would add is that my barn passed code review and final inspection with UC3B skirt boards, which are not rated for ground contact, and the plans examiners raked me over the coals. They would have jumped all over that if it was a problem.

 

[Mac25]

It's not quite that simple. If it's floor joists in a crawl, the rule is clearance of less than 18" requires an approved protected lumber ** (see list below). If beams in a crawl, 12". If wood siding/sheathing, 6". Framing members that rest on concrete/masonry, 8". And sills/sleepers on concrete/masonry only need a moisture barrier. I don't believe there is a category that covers skirt boards on a pole barn, and that aspect of the barn is likely not covered by code anyhow (or it would be the inspector's call). Note in the types of lumber below that there are numerous categories that are acceptable to code that are not ground-contact rated (only C4 is ground contact rated). So anyhow, you don't necessarily need it to be ground contact rated, and the 8" number is specific to framing resting on concrete/masonry. ** Approved lumber is one that is pressure treated in accordance with AWPA C1, C2, C3, C4, C9, C15, C18, C22, C23, C24, C28, C31, C33, P1, P2 and P3, or decay-resistant heartwood of redwood, black locust, or cedars. The only thing I would add is that my barn passed code review and final inspection with UC3B skirt boards, which are not rated for ground contact, and the plans examiners raked me over the coals. They would have jumped all over that if it was a problem.

I have already had the final inspection, which was nothing more than a visual so I am not worried about that aspect. Just wondering the best way to keep the skirt boards from bowing when concrete is poured. My posts are 9' OC and there is a little flex in them. I didnt want to build a bunch of wood anchor supports, but will if thats the best way. I didnt know if back filling the outside was the more convenient method instead of wasting money on more wood to brace it.

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[s219]

Did you see the picture in the thread I posted a few days ago? That's what you need to do in my opinion. Could be as simple as stakes driven against the skirt if you only have one board.

 

[Mac25]

Did you see the picture in the thread I posted a few days ago? That's what you need to do in my opinion. Could be as simple as stakes driven against the skirt if you only have one board.

Yes I did see the pic, thank you

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