Had a 40x60 pole barn built with the long side (60') running the slope.

Just eye-balling it, the builder guessed the drop at the back was going to be around 4'. Well, when he shot the thing it turned out to be 8'! [img]/forums/images/icons/confused.gif[/img]

I didn't have any experience dealing with building on a slope like that nor did anyone else I knew so I had nothing to go by but to trust his judgement on how to handle it (this guy was an experienced builder).

Here's how he did the fill: He had a guy haul in 20+ loads of fill dirt and used that to build a slightly compressed dirt berm all the way around the perimeter. Then he filled the inside with blast rock fines. The result was an extremely steep dirt slope in the back, 10' at one corner and 7' at the other. The land in the back continues to fall away at a steady rate so there was no way to continue to add fill to bring the slope up to anything that would hold.

At that point, we had a couple of rains before I could do anything to address the problem and the dirt in the back began to shear down and away from the building, opening up a deep chasm. The wife and I had to take a day off from work to wrap the whole thing in plastic sheeting to minimize any further damage until we could get it fixed.

THEN BEGAN THE MARCH OF THE RETAINING WALL CONTRACTORS! I talked to so many people it'd make your head swim. A number of them suggested, as the cheapest option, to use blast rock to shore up the berm. I live in the woods and like it that way. Therefore, I wasn't interested in taking out any more trees or staring at a huge pile of fill rocks every time I look out my back window, so large blast rock would have had to be used to provide any reasonable slope and minimize its footprint. I asked each person who suggested blast rock a simple question which none could suitably answer: How do you keep the dirt from, over a period of time, washing down into the voids between the blast rock? They himmed, hawed, and zig-zagged but none could say for sure, or guarantee their work against that happening.

The next cheapest option was a guy offered to, essentially, pour a basement wall around it, maybe with a sleeper or two, and fill the gap with blast rock. Several things bothered me about this idea. The first thing was that he was proposing to make the wall no thicker than a regular basement wall, 8". An 8" wall to hold back tons of rock and dirt just didn't sound right. Another thing was, the way he was talking, I got the impression he had never done a job like that before. Would you like to be this guy's guinnia pig with a $22k building at stake? Not me.

So we arrive at the last option, a block retaining wall. If you've never priced a real retaining wall, not the 3' landscaping variety, better be prepaired for sticker shock. Anyway, we ended up with a Versa-Lock wall about 8' high in the back and wrapped half way up the sides of the building. Clean rock fill was used on the inside with geo-gridding and compaction.

We've had a lot of rain lately and the dirt has continued to settle, but at least the shearing has stopped and the settling is more or less staight down. There's about an 8" drop away from the poured concrete floor in the back now so I'll still need to figure out some way to pack underneath there to slow the cracking of the floor.

Total Costs:

$22,000 40x60 Pole Barn w/Poured Concrete Floor, Gutters, & Roof Insulation
$5,000 Fill For Site Prep
$15,000 Retaining Wall

Now, IMHO, knowing what I know now, how it should have been done. The whole thing should have been put up on blast rock from the git-go...big stuff at the bottom and smaller on top. This is the way they fill entire valleys when they put in a new highway. This is the way some floodplain was raised here locally to build the new Wal-Mart. A depression in the middle could have been filled with blast fines where the floor was going to be poured. The fines set up like concrete when compacted but have enough give to float a concrete slab. My guess is this would have saved me $10-12k overall and no further settling would have occured or further shoreing up would have been needed. The overall footprint wouldn't have been any bigger than the one I have now and no further tree clearing would have been needed.

Hope this helps someone.