Construction Question

[Lurch1]

It isn't a coop, but I didnt know where else to post it. I want to build a bard approx 20x40 on the new property we bought. While clearing the land for my coop, I found that the soil is black earth about 2 ft deep and then goes to green clay. I have been told that it is not recommened to build on as it can sink a little. Any ideas on how I can build a barn with a hay loft on my land?

 

[gibsonbuzz]

You need to talk to the building inspector in your city. He will know what you want or know or who to talk to if he does not know.

 

[Bear Foot Farm]

You'll probably have to dig down to the clay layer and pour a concrete footing, unless you are building a "pole" barn.

Your local building codes will tell you what's required

 

[ourflockof4]

The "black earth" is your top soil layer. Traditionally you should always scrape your top soil leyer off before you build. Whether you are builting a pole barn, or a full foundation you will need to go down below frost depth regardless with you pole/foundation. Chances are that in your location it is 48" or deeper. I agree that you should check with your local code/building dept for the regulations. If your location is anything like mine though you may not have a building dept, or any enforceable code to build by, especially with an agricultural use. I would check the min frost depth regardless though in the International Residental Code, I beleive if has locations listed in Canada, if not your closest city should have a building dept that could tell you that.

As for removing the top soil though, that is just industry standard. Depending on what you plan on doing for a floor you may be able to leave it and just remove the vegative layer. A stone floor with light use may hold up with the topsoil in place, but with heavier use, tractors, equipment ect., it may not hold up well. Just my opinion though, I do realize that 100 +/- ton of stone is more then most are willing to do.

 

[Lurch1]

I will check with the building authority and see what they have to say. I was told that the green clay was not very stable when supporting a structure.

 

[ourflockof4]

They clay is probably fairly silty, wet clay then. Really the only way to deal with that is to either go deeper until you find a suitable bearing condition, or do larger spread footings. If you are planing on a pole structure you may be able to get away with digging a larger diameter hole for your post. Maybe a 24" dia (or even larger) instead of the typical 12" dia. holes. Hopefully your local building dept can help you with that.

 

[patandchickens]

Do a pole building, not something up on blocks. Use enlarged footings for the posts - either poured concrete in forms, or them "big foot" plastic things you can buy. I would consult with a local builder or building-code guy for specs.

I would highly suggest SKIPPING the hayloft. It will greatly increase the pressure/stress on the ground supporting the footings, and require much more serious engineering than if you did a 1-story barn. Build an addition, or separate shed, to store your hay in. It is easier and safer, too.

Good luck, have fun,

Pat

 

[Lurch1]

There is a high water table here as well, so the ground is wetter then average. Would this pose another issue?

 

[imthedude]

hire an engineer and a builder to come up with the best and most economical solution for your site conditions. building inspector/code guys will just tell you what code requires, which is sometimes overkill and can be deviated from if warranted. i moved my shop/garage foundation up above frost depth because it is a smaller building (little bigger than 600 sf) and will act as a single unit when frost moves it. pay a professional and get a professional product.

 

[ColoradoMike]

Quote:
Beat me to it, Dude

Hire a geotechnical engineer - they (read:we) specialize in testing/analyzing soil for support of foundation/floor slabs. Geotechs work in concert with structural engineers to provide the appropriate foundation solutions given your site-specific conditions.

Good luck!