# How much dirt do I need to raise my driveway 1 foot?

We’ve had some major driveway issues from the day we bought our house. We have a very poorly maintained gravel driveway. It is so bad that the water is actually carving into it. We need to raise it, by about a foot so that the water no longer runs down it. That should solve our problem at least for a while.

The part I need to raise is 400 ft long and 10 ft wide.

Bonus question: Our entire driveway is 770 ft long. How much gravel do I need to order to cover it?

According to this, you need 240 tons.

Skimming a few aggregate/building materials suppliers, it looks like gravel costs between \$25and \$50 per ton- so you’re looking at \$6-12,000.

ETA: You’re trying to raise it with dirt, and re-gravel the top layer. Whoops.

Okay, I’ll try again.

You need 400 cubic feet of dirt, or 148ish cubic yards. Dry sand weighs about 1 ton per cubic yard, so 148 tons.

You need 77 tons of gravel to cover the whole thing at 2", assuming it’s 10 feet wide all the way down.

FYI, unwashed low-grade loam is under \$5 per ton.

Well I’ll be darned. Apparently they sell it by the cubic yard which makes the whole calculation a bit easier. I need 400 sq feet which works out to about 15 cubic yards. A load is 14 cubic yards, so I’ll get two loads at 90\$ a piece. I figure the road will compact quite a bit. I can use the excess for to fill in other parts.

15 cubic yards, not 150 :smack:

Guys, I thinks you are a factor of 10 out. 400101=4000 cubic feet which is about 150 yards.

And the dirt will compact a lot. It needs to be spread thin and rolled (compacted). Repeat.

I’d use rock/gravel, starting of with real coarse stuff, 4-6 inch across for the bottom layer, getting finer for each layer. Each layer needs compacting.

Your right, I’m off by a factor of 10. I need 150 cubic yards. So I need about 11 loads. Damn, that’s a lot more expensive. I thought I was going to save a bundle by doing this myself.

Hey, I was right the first time!

Now I’ve got to figure out what type of equipment I need to spread all that dirt.

Isn’t a cubic yard 3ft3ft3ft=27ft?

Sorry, I deal mainly with metric so I might be wrong but there’s no way 2 truck loads would cover that area at that depth.

To double check using metric, say the drive is 130m by 3m and the depth is 300mm. So 13030.3=117 cubic metres. Ten to 12 truck loads around here.

If you’ve go a guy delivering the dirt, he might have the gear. Else a 80hp min. tractor (for weight) with a rear blade. Get the truck to spread the dirt thin (4" thick) then drive the tractor over the dirt, using it’s wheels to compact. You will need to drive back and forwards lots of times. Then get another layer spread. Use the blade to smooth any lumps and bumps and by putting the blade on an angle you can crown the surface so water drains away.

You will need a drainage ditch or 2, too and maybe a culvert.

Yep.

Assume the soil and stone to compact at least 15%. At least, that’s the figure we use around here (landscaping rather than blacktop work).

You are right dynamitedave, but we did already figure that out. We already have two culverts, but they aren’t very good. One of the culverts doesn’t actually drain anywhere, so we plan to dig out a path for the water to drain. We may dig out a trench on one side, but I’m not sure that we will do that this time around.

I see what you did there

Multiply by 1.5 for compaction = 222 c yd. If you are using standard compaction (95% of Proctor density), then your ratio will be about 1.5; that is, to get 1 c yd of compacted dirt, you will need 1.5 c yds of LVM (loose vehicle measurement).

I recommend that you take care of whichever drainage problem is causing the erosion you mentioned, first. No sense putting down all that material if it’s going to wash out.

Good luck.

You don’t say what our location is. But what I think you want is road base. Not ‘dirt’ covered with gravel.

And not gravel. You want road base.

Depending on the company, they should be able to help you spread it as they dump it. It’s just a matter of chaining the tailgate of the truck closed to a few inches and driving as you dump. Any good driver should offer to do this.

What type of access do you have to machinery? I have a small tractor with a box scraper for my own drive. I bring in a tandem load every two years.

You are going to need more. If you can rent a 480 or 580 size Case (or similar) with a box scraper and a bucket, that should do it.

Provided you get enough material.

And as others have said, you may need to consider a culvert or two to allow the water to run under the drive. For that you will need a backhoe. Same machines, different attachments.

Raising the driveway will do a good bit to solve the drainage problem. In it’s current state, the water is literally running lengthwise down the driveway in a hard rain. I’m told the rain we had last spring was very unusual, but clearly the driveway is a problem. Even without this work, I have succesfully stabilized the worst part of the driveway which was the culvert that doesn’t drain.

I can’t imagine what the idiots thought when they dug a culvert that just went under the road without draining. I actually talked to the previous owner who clearly had no idea why the soil kept washing away at the culvert. Still, digging it to a drainage point isn’t easy, ande it could remove our emergency exit.

You absolutely do not want to use loam. It’s basically all fines and some organic matter, and will quickly wash away. Good for gardens; lousy for construction.

Regardless of location, road base is processed aggregate, consisting of a well-graded mixture of crushed stone. This is often informally referred to as “gravel.”

If you want a uniformly sized aggregate (which does not make a good road base), you order “crushed stone” in that size.

What I’m going to order is a mix of clay and rock. I don’t remember what they called it, but it’s what I need. I will cover that with aggregate.