fill dirt and surface preparation

Anonymous Poster · Apr 24, 2001

I had the good fortune of obtaining about 20 dump truck loads of fill dirt. The county knocked down part of a hill by the road at the end of my property (to improve visibility), so now I have the fill dirt I've been wanting for quite a while. I'm building up an area 20' wide by 24' long for a future pole barn right next to a concrete pad next to the house. The area I filled in was about 4' lower than the concrete, but now I have it up level with the concrete. The fill dirt is clay and packs down real nice. I used my rear scoop (don't have a front end loader) and grader blade to get it into pretty decent shape, and my neighbor has a box blade I can borrow to finish it up.

Now for my questions.

How much wider than the pole barn does the fill need to be?

At what angle should I slope it down on the sides?

How long do I have to wait for it to settle before I can dig holes and put in the posts?

What do I need to do to prepare it for pouring concrete and how long do I have to wait for it to settle before I can pour concrete?

If I use it as a parking pad for the rest of this year, should I just put some stone on it until I pour concrete? If so what size stone? Will I have to remove the stone before I pour concrete later or can I just pour concrete right on top of the stone?

Thanks, Danny

MarkV · Apr 24, 2001

Danny,

Sounds like you got lucky. That much fill would have cost a few bucks to bring in. I sure don't have the answer to all your questions, but I do think you are asking the right ones.

The rule of thumb around here is two years for uncompacted soil to settle enough to build on. Of course like all rules it depends on many things. Your clay should compact better than some other soils. For a pole building, if the poles are drilled down to original grade, I would think you could be good to go right away. Gravel is great to put down under a future slab. It will help stabilize the new soil and offer a drainage base under the slab. In many areas, putting gravel down first is the norm. I would start with a 1 1/12 - 2" stone to form a base and follow with a crusher run which has stone dust mixed in to lock the stone together.

MarkV

Boondox · Apr 25, 2001

Danny -- I have no advice but MAN could I use that much fill!!!

Pete

www.GatewayToVermont.com

WVBill · Apr 25, 2001

Danny:

My concern would be setting the poles in the fill dirt. MarkV had the right short-term approach - sink the poles down into the original soil.

When I built my pole barn, I heavily used a couple of reference books I got from Amazon.com. Just search for "Pole building". I don't have the books with me right now but I recall that there was some lengthy discussion on the type of ground required for sinking your poles.

Anonymous Poster · Apr 25, 2001

I had about a 60x130 site prepared for a 40x110 pole barn last year. First the topsoil was stripped and saved, then one side was cut down to make a swale, and the other side built up more than 2 feet with bank run gravel dug from another spot on my property. Then the whole mess was compacted with a vibrating roller. I put down a geotextile mesh and covered it with about 200 tons of crushed concrete (although this had so much metal and wood in it that I would pay more for crushed limestone if you weren't going to pour a full concrete floor). Then it was compacted again. Final slope on the swale side is about 10%, the side I have to mow is about 5%. During construction the slope was greater.

I've been warned that the vibrating roller is real bad for existing concrete. But my barn is over 100 feet from my house, and the roller let me build right away. If you don't compact your fill then I think you shouldn't put stone on it until it settles for at least a year, if not two.

Everybody pours concrete on stone. The biggest problem I had was the clay deposited by the post-hole auger, and tracked around while setting trusses. Cleaning up the mess was a pain, and would have been easiest as soon as the posts were set.

Rch · Apr 28, 2001

My neighbor has a large pole building and the backside grade falls off 2 feet from the back wall to a little valley. The roof has practically no overhang. The poles on the backside have heaved up from the ground being so wet with the frost since the " valley" kind of holds the water. He had to put a rain gutter to carry the water away since he doesn't have room to change the grade. Bigger eaves would have helped. Bigger eaves make a building look less like a machine shed and dresses it up, in my opinion.

RCH

Bonedaddys · Aug 16, 2014

It was good to see your post regarding fill dirt. I live on a mountain at 8,000 feet outside of Denver. To get fill dirt up here is impossible. I have a 60' wide sloping area that drops about 15' from the top side of the area I want to build a garage or pole barn with concrete flooring. A trucking co. Contacted me this week and out of the blue I now have 640 tons of clean fill dirt mixed with clay that now flattens out the side of the mountain. I know there are a lot of red flags going up and I am now staring down a huge amount of work with 15' high fill dirt walls on the low side. At this point I'm thinking the next thing to do is contact an excavation company to come out and assess what to do next. Or should I contact a builder or the county for the next step?

dave1949 · Aug 16, 2014

Welcome to TBN!

Congrats on your fill dirt score.

If you intend to build, pour a slab, on that area it needs to be compacted correctly. Would it be vulnerable to sliding down the hillside and need some sort of retaining wall or other stabilization?

I would ask around for a good excavation company, have them visit and depending on what they say, you may need some engineering help, or it may be fairly simple. You need an experienced eye to steer you in the right direction.

Bonedaddys · Aug 16, 2014

Thanks for your advice, I will contact a good excavation contractor Monday. Not planning to build for two years so hopefully settling will be ok once the dirt is moved and positioned for a foundation. I'm just glad to finally bring my fifthwheel and trailers home.