BHT Revised: 09 Sep 2013
Fix the Stone Driveway
Our stone driveway was truly in need of repair. The driveway stone has been overgrown by weeds and grass. The stone has sunken into the ground creating tracks the rain just pours down, forming mud tracks whenever there is a heavy rain. In the winter the situation is worse. Our stone driveway is on a significant hill leading up to the road. With drainage coming down the stone tracks, a thick layer of ice forms and can last most of the winter. The driveway is so slippery we end up parking one or two vehicles at the top of the driveway adjacent to the road so we can get out reliably after a snow, or worse, ice storm. Also we really need a parking area for 3 to 4 cars. To date, we have just been pulling the cars onto the lawn. One of the problems is we live on a dirt road, do not get me wrong a well maintained dirt road, but the key word is dirt. No matter what you do your car tires track dirt onto the gravel driveway ultimately providing a perfect growing medium for the weeds and grass.
You can see we have a decent hill to climb to the road. In this shot you could get a rough idea of where we parked our vehicles in the winter. The driveway was slippery enough in the winter that I learned to back the van down the driveway in neutral. Why? If not in neutral the engine has enough torque to drive the rear wheels just a little, making the front wheel immediately slide, AHH!. The front of the van would immediately start to swing around trying to pass the back! Put the van in neutral and I could back (coast) down the driveway fine. All four wheels would hold under braking.
The stone to repair the driveway
The 75 tons of stone for the fix cost about $650 delivered. There was a $2.00 a ton delivery fee. Each full truckload was about 21 tons. I called my local quarry and they suggested a delivery day of next Monday which was fine with me. So about 9:00 AM Monday "Lucky" rolls up with the first load. Lucky says yup my name really is Lucky. Basically I had told Keller's crushing I anticipated needing 3 full loads, so Lucky was sort of my driver until I stopped telling him to bring stone. I was able to spread the first load of stone before Lucky returned with the second. But after that he was beating me in the race, which means I had to guess how much I needed and also work around the stone piles themselves. I only would dump the stone where the driveway was going to be. I did not want a big cleanup job in the lawn and tarps have their difficulties too.
Preparing the "driveway" for the stone.
The original driveway was about 130 ft. long. It was a little "wider" adjacent to the house. So a good portion of the driveway did have a reasonable foundation. This had been done when the house was constructed. Several inches of 3 to 4 inch Rip Rap stone had been put in, then probably, some 2B modified stone on top. Modified seems to mean mixed with smaller stone and fines, stone dust. I really needed to excavate around the perimeter of the area I intended to cap with stone. I was shooting for a 3 inch layer. In the photo above I had used the tractor bucket to "scuff" up the existing stone and rip off most the grass and weeds. I "bull dozed" and "back dragged" the bucket to do this.
I also was adding a parking area, lots of stone.
The parking area has no existing foundation. What I should have done, but did not for only one reason, was put down soil stabilization cloth. If your doing a driveway from scratch, I could see excavating about six inches of soil, then lay down the stabilization cloth and just pile on the "2A modified" stone. The Rip Rap was the traditional method of making a strong foundation, but it does not keep the stone from mixing with the soil over time and slowly sinking in, pretty much forever. The stabilization cloth stops this and if buried deep enough allows long term maintenance of the driveway. Also the cloth "holds" the stone together distributing any load on the driveway over a large area. Since I was just repairing the driveway I could only partially get the cloth deep enough and would be concerned that I would rip it up during future maintenance. I anticipate in the future needing to rough up two inches of surface and then add more stone on top. Remember the driveway will probably just keep sinking for quite a few years.
So for the parking area I just excavated about 3 to 4 inches down. Because of the side hill slope, the stone for the parking area might actually reach a foot deep making a pretty strong foundation. I researched parking lots and allowed enough space for 4 cars. You do need quite a bit of width for pulling in and and backing up. I also had to remove a ridge of topsoil to assure at least a 4 inch depth of stone.
Drainage around the driveway
Drainage, was a significant problem. The parking area was going right on top of a drainage swale. So I had to add perforated drain pipe under the entire parking area. So I notched a little area for the pipe exactly where the swale currently was. I wrapped the pipe in landscape cloth, and I had literally "tons" of stone to cover the pipe, which is the first thing I covered. With about three inches of stone over the pipe I was able to safely drive the tractor over the pipe. Now the water will run under the parking area and all the rain landing on the parking area can migrate to the perforated pipe and drain away.
Also I had one other drainage concern
My driveway is below the street, and therefore, the culvert pipe used for street drainage. I believe, even though the 30' x 1.5' pipe is well installed, during heavy rains water undermines the pipe. And what does that water find? Beautiful porous Rip Rap driveway foundation stone so that about 30 feet down the driveway from the culvert pipe a little water magically wells up through the stone. So I have made my own perforated 1.5" pipe and place four diagonal segments to divert the water to drainage areas in the lawn. Again I just wrapped this pipe in landscape cloth and buried it in the new driveway stone. In the photo above are two of the four diagonal pipes notched in and ready to be covered. The thought is if water does migrate it will run between the old driveway surface which is half clay and the new stone covering these old driveway troughs.
Also in this photo you can get a feel for what a 21 ton pile of 2A modified stone looks like.
More preparation for the repair
The original driveway had already sunken somewhat. It was five years old. Not only that, but what happens is the perimeter of the driveway also is pushed up as the stone driveway foundation spreads under load, and time. This was truly great, it provided about a 4 inch stone retention area. There are probably portions of the driveway where I added 8 to 10 inches of stone.
I used the tractor bucket too!
I used the tractor bucket to spread the stone, then back dragged over the stone to level it out. I tried to always keep the tractor on the driveway, but to grab fresh loads of stone I had to go on the lawn. But I really did not end up doing much harm to the lawn at all. Once most the stone was spread I was dragging the tractor bucket over the new driveway repeatedly to feather it into a smooth surface.
The driveway meets the street.
Here I always want my driveway to be elevated higher than the edge of the street itself, diverting any water around the driveway and into the culverts. You do not want to get carried away because when the snow plow comes all that stone may end up in your lawn! Also I notched the street itself uphill of the driveway to divert any water to the culvert before it reaches the driveway hopefully cutting down on mud tracking in on car tires.
The driveway is not done.
I may bring more 2A Modified to level the stone driveway a little more. After recent rainstorms it has settled some and is not perfectly level, not that it ever will be.
Also I will probably add at least 20 tons of "1/2 minus". This is 1/2" and smaller stone with lots of fines. This can really smooth and pack down the surface. Even now there are sections that the fines have packed into what almost looks like a smooth concrete aggregate surface.
I use a snow blower just set up with an inch and a half clearance. Very few stones get thrown. Since I have used a smaller stone than my original driveway builder, I think I will have less problem. (You can go too small though!). That's one worry with the "1/2 minus". I will probably add that next year.
Now with the driveway surface above the lawn surface it should get blown clear of snow rather than filling with snow. When traveling in the Midwest and Central states I have noticed how many highways are elevated above the surrounding land, and the wind just clears these roads beautifully!
Edging the gravel driveway
There are areas where the stone sticks up 3 and even 6 inches above the lawn. My intent is to backfill these areas with topsoil sloping up to the driveway and then reseed. (Next spring).
I did rake the entire edge of the driveway stone by hand just to get any spillage out of the lawn. It really came out pretty neat. I only have landscape timbers where the sidewalks and flower gardens are. These are perfect for separating the stone from the gardens and walkways.
A trick for the landscape timbers
Drill two 1/2" holes one near each end of the timber. Now just drive a 2 foot piece of rebar through the hole into the ground. The rebar is so strong it will usually shatter any rock it runs into. WEAR SAFETY GLASSES when using that sledge hammer! I put the timbers on edge giving a nice bull-nosed edge effect. Note: I used landscape timbers with rounded edges; I think 4 x 4's would have been better. By putting the rounded edge of the landscape timber down, it became an easy target for frost heave; slowly pushing the timber up out of the ground. The rebar works well though for stability. Perhaps if I had used 3 or 4 foot piece of rebar, frost heave would not have been an issue.
I hope this helps repair your stone driveway
by Bob Matheson