Base for shed

[foggy1111]

My son-in-law is just about to have a new pole building put up. (42x64x12 high)

His soil is mostly clay and the clay runs pretty deep. The site he has chosen has some fall from one end of the proposed building site to the other....maybe 3 feet or more....but I am going to check it today with a transit. So my question is what to do about fill / base.

At this point I think we are going to scrape away any top soil (not much of that) and then place pit-run gravel to build it to the floor level (and try to compact it as much as possible). After the building is built he will re-level the site and then put in a concrete floor. I think we will need to rip-rap around the gravel berm which will be about 4 feet from the building perimeter.

I know the base is critical to a good floor.....Am I missing anything with this plan???

Any advice is appreciated!!

 

[JDGreenGrass]

Sounds like a plan to me.

One thing I would add is, while the 4' is likely enough, 8, 10 or 12' around the building would be better. I know, $$$.

Maybe let some rain hit the gravel before deciding on the floor grade, just to let it settle in a bit.

Boy, nice big building. Best of luck with the construction.

 

[oldnslo]

I would put the poles in the virgin ground and not the 3' of fill.

 

[foggy1111]

Thanks for the advice. Yep...I hope we get some rain (and expect we will) to help pack the new fill. Then too, the crew will be operating over the fill site with their equipment and we will work on it as much as possible to compact it. Also the concrete crew will compact it with a vibratory packer before the floor goes down.

He does have some other clay to place....so maybe that could be put around the new fill area to extend it out some distance. Good idea. :thumbsup:

Here in MN they normally will put the poles down about six feet and put a concrete cookie at the bottom of the hole.....so I'm sure we will be in old (virgin) soils where the posts are set.

Thanks for the advice. Always helps to have another opinion. :thumbsup:

 

[jdmar]

I agree I would put the poles in/skirt boards then fill inside and around the outside of the building-if you have "free" clay onsite I think that would fine outside where I presume you are not putting concrete. And remember compact if lifts not after it is all in(that just compacts the top few inches but the base below will still settle. Most compacting recommends moderate moisture to allow full compaction also. I was lucky since my barn is next to a creek and I could use a trash pump to add water to help settle it..I did this several times. I was amazed how much it settled! Do you need to add drains under the pad so it doesn't collect water in what may be a "clay swimmingpool?"
And that sounds like SOME building. I would hate to see the concrete settle too much over poor fill. Do you know where you could borrow/rent/hire a large vibratory roller or sheepsfoot!?
Peter

 

[PA hayseed]

do you have shale in your area? clay and shale make a very solid base. I had about 2.5 feet of drop in my pole building over 40' length. I had shale dumped and dozed, then run again, let it rain on it, then I had it rolled by an asphalt Co roller. Hard as a brick. I then used gravel before the concrete floor.

I don't know if you have shale in your area, but in my area it is plentiful and very cheap.