Preparing for a building pad

[Prefect]

How accurate do I need to be in grading for a building. It's going to be a steel building about 60x100. I haven't ever done anything for a foundation before. Should I just pony up the $$ or give it a shot. I have access to a small dozer/highlift, and a CUT with a box blade and FEL. I just don't know how precise I have to be for the pad to be poured.

Thanks in advance.

 

[notamustang]

I am by no means qualified to give you a good answer but for a pad that size I would pay someone.
My reasoning, is it being inspected ? How sure are you of being able to get the proper compaction? And the most important is its a large pad and building, I would want to blame someone else for the errors /forums/images/graemlins/smile.gif
If the pad varies thickness the only real thing youll loose is money for extra material for the pour.

 

[bugstruck]

Prefect, It should be near perfect. If you've never done this you still could get it right. That would be within an inch or two total variation. However, it's not nearly as easy as it looks. You could put me on the same dozer as a real operator and I'd get it just as good in allot more time. Probably double or triple the time. I've spent more than a few hours on them but you can't beat a man at his game.

So if you have the time, don't need to do much fill and compaction, don't have allot of cut material to remove, and have access to the equipment you mention, I'd do it. What's the worst that could happen?

 

[Slippy]

I have done my own, not that big, but with a FEL and box blade. If it is a pole barn construction, you can get it close and bring gravel in to level it off. Just want to make sure you are not making a big hole for water to drain to. You could always do the rough grade yourself and if you are going to pour a floor, they can do final.

 

[Prefect]

It's going to be a large steel building, like the General Steel type. It's for a church. One of the members is donating the equipment (a highlift and a dump truck), for as long as I need them. This is equipment he uses on his farm and is not for his business, so he said take as long as you need.

Now, I need some surveying equipment (and expertise) donated and I'll be set.

 

[have_blue]

A level, framing square, and string line will get it as accurate as you need.

I have built many slabs, and it's no sweat. Well, maybe sweat, but no worries. /forums/images/graemlins/wink.gif Make sure you remove and replace all the dark topsoil with a good non-shrinking clay or loam. Compact it well. Use plenty of foundation grade clay-sand in the top 2 feet. Keep your perimeter boards level, without swaybacked boards, and brace the corners and any high places with dirt and 2x4 braces nailed to stakes.

Leave the concrete finishing to the pros. I finished my own recently, and the slab came out OK, but I didn't fare as well. /forums/images/graemlins/crazy.gif

 

[moeh1]

Good advice so far. It depends on alot of factors, you need a few people who know concrete. also, what the layout of the land is. Attached is a 25 x 40 barn foundation, fairly level and not that fussy. We had 5 guys ( all with alot of experience) hustling for several hours for pour and finish, along with setting the perimeter metal for the barn. I'm very happy with the results and would repeat it anytime, but there is a fair amount of prep work for leveling, stone drainage, forms, electric, etc. ( no plumbing in my case).

 

[moeh1]

One more pic

 

[moeh1]

One final shot showing some bracing and some finishing.

 

[gates]

Prefect,Grading is by no means brain surgery. You can do it, if you have the equipment. It is a time versus money thing if and only if, you have good soil conditions ie. what type of soil, where is the water table, compaction of the base, were there any back fill conditions and were they compacted properly. The answer to these questions will directly affect the slab, if it is slab on grade, and ultimately the building.
If you do decide to attempt the project, buy yourself a tansit, or if budget allows a low cost laser, it will be the best investment you could make, besides lunch!