Preparing a site?

[64dragnwagon]

I am going to start sitework for my 40X100 building. I am debating between a pole building or a red iron building. I think the nature of my site may have some bearing on the type of building I go with. I live in the mountains of East TN and my site is currently a long way from flat. I will have to push dirt off a hill and the building will sit on fill dirt entirely. I feel I may have issues with either type of building. If I go with a pole building do the poles have to be sunk all the way through the fill dirt to the original ground? If I go with a red iron do the footers have to go all the way to the original ground? We are talking about fill dirt as high as 5 to 8 ft deep in some spots. I can have the dozer pack it down as they go but it is still fill dirt. Any suggestions? Thanks: Marty

 

[PAToyota]

Best case is to bear on undisturbed soil. One thing to do is have the dozer fill things in by "lifts" of a foot or two - that is, put down a foot or two of soil and then run over it to compact it. If you just dump five to eight feet and then try to run over it you will definitely get settlement. Also, talk to the pole or metal building people about their requirements. They can point you in the right direction or oversize the footings to meet the requirements.

 

[Charles (in GA)]

My personal feeling about fill is that even after packing, it needs to sit for quite a while to settle, I just don't think you can push dirt, run over it with a loader or even using a sheepsfoot and not expect it to settle some more. I certainly would not want a pole building anchored in recent fill dirt, it just don't seem right.

A metal building largely depends on a slab to hold it down and keep it from blowing away. The footers provide extra strength in the area of the columns and around the edge but you are not talking much depth in any case, probably 2 ft or so at the max. Thus the metal building can "float" on the fill with much more success than a pole structure, which is much more dependent on the underlying soil. In any case, you should make sure you have more than normal reinforcing in the slab, rebar, wire (dealt with properly by the finishers) and I would key the slab with metal keys rather than saw it. The keys will help prevent shifting of the slab sectionsm which is more likely on the less than desirable base.

One of my neighbors used fill under his building and now he has a cracked and uneven floor.

Not saying its impossible to put down fill and build on top of it, just requires alot more work and expense than most contractors are willing to do, or think need to be done. Contractors will rush things, saves money. They do not have to endure the bad results of their work, they move on to the next job, you have to live with it.

Charles

 

[64dragnwagon]

I have no choice but to build on fill dirt. The property is just to uneven. It does make sense that a metal building with a slab might work better because of the ability for it to "float" on the dirt. I talked to a professional dozer operator and he said he should be able to pack it like was said earlier a foot or two at a time. Then to be sure he said you could rent a motorized tamper and tamp down the hole where the pole is going before you put the concrete and post in the hole. I will do the site work this fall then let it set all winter and build in the spring. Thanks for the good info.

 

[trs900]

I had the same problem I put in a pond and used dirt to build pad with, some places almost 15ft high. Dirt was compacted as it was dropped off by pan, tractor and pan weighed over 70,000 lbs. then as it was dropped it was graded immediately with a box blade so it was always a thin layer of dirt rather than big piles and each time the pan and tractor drove over it it was compacted further. We just poured slab and I can tell you it was tough digging for footers, plumbing etc.. now this is in southern Georgia clay or should I say rock. I feel this method worked well here in Georgia

 

[trs900]

If it helps you feel better about building on fill dirt, every home here in area of Florida where I have a house is built on fill dirt usually about 4-5ft high due to water tables and septic tank, been that way for many years and I have not seen one with any serious problems.