Building a Gravel Driveway

[Rich Riddle]

I know a few basics about building a gravel drive and have read several articles on the topic but still have comments and questions.

1. Some folks want the drive to be three layers of varying rock with each layer 6" thick; that won't happen. I am not trying to build a road to Athens. Is 4" a reasonable depth for each layer?

2. Concerning layers, many say 3" - 4" rock for the bottom layer. Will 209 stone suffice? I am not quite sure what it is, but the quarry a couple miles from the farm has it.

3. I am likely going to cut into the hillside to bury the drive or only have it above the grass a few inches. Is there a reason to have it a foot above the area around it?

4. Is 12' wide sufficient?

5. Everyone seems to recommend an underlayment cloth in heavy clay soil, which this is, but do you also recommend having an "edge" on the driveway such as railroad ties? This drive will be about 300' long. That's a lot of ties.

6. Some dealers want to quote in cubic yards and others in tons.....how does one calculate apples to oranges?

Thanks.

[Brent Cutshall]

As far as cutting a divot in the ground to for the driveway, it'll keep the rocks in better but it might funnel water into the driveway when it comes a monsoon. With my driveway, I don't think we've ever had any more than 3" deep of rock and I could say the same thing for the rest of the local folk too. I'd like to ask if you'll be putting yours on a hill. Mine is on a hill that raises from about 1000 feet to about 2700 feet in just over 150 yards, it's a steep hill. On the flattish spots the rocks stay there pretty good, but on the hill they'll gradually wash down. The friends down the street don't have really any problems. Oh, and we've got clay under ours.

[Jerome Stanek]

When I was running heavy equipment this is what we did. remove the top soil is a must the we would put down 4 to 5 inches of number 2 stone pack it in with a piece of heavy equipment we had a 211 pay scraper that we would have the belly full on dirt then 4 or more inches of 67 or b211 stone. The most important is remove the top soil as it will just keep coming to the top and make a muddy mess

[Bradley Gray]

My experience with roads in clay is the clay will suck down just about anything you throw at it for a few years, especially in winter freeze/thaw cycles. I would stick with coarser rock for a while.

[Lee Schierer]

You definitely want to put down geotex fabric or the gravel will slowly merge into your clay. You also want to removed the top soil and put down a base layer. You need to consider drainage of the road way and the areas surrounding it. Any low spots will collect water and cause future problems. Likewise any areas where the driveway is higher than the surrounding land will act as a dam and stop storm run off. Your local government may have codes that apply and you may need a permit to cross any ditches to the main road.

[Nicholas Lawrence]

Like so many things, there is the "right" way, and the way that you can afford. They do not always overlap for me. To do it right, you need a good base (compacted), and the advice you are getting about multiple sizes of rocks in multiple layers is probably good, but it sounds a lot fancier then any gravel road I have ever been involved in. In other words it is probably good advice, but if you can't make that work it is not the end of the world.

Growing up, a lot of folks just put down gravel, and drove on it. After a while, you would have spots that needed more gravel, and then they would add more gravel as needed. For the first couple of years that might be quite a lot of new gravel. Over the years of driving on it, the gravel would sink into the ground, and everything would get compacted, and eventually things seemed to reach an equilibrium where you did not need to add much to it except an occasional pothole every so often.

In terms of cutting in, or having it protrude, take a look at a decent dirt road sometime. You will likely notice that they tend to have a crown, and are elevated a bit. Mostly so they shed water as far as I can tell. You do not want a lot of water moving across a dirt or gravel road, because it will wash out regardless of how much landscaping fabric, railroad ties, or whatever you use to try to prevent it. You want to lay it out in a way that lets it shed water to the sides to runoff someplace away from the road.

[Brian W Smith]

Drainage ends up being the metric...more so than materials and methods.Having been seriously involved in historic preservation work,I spent quite a few brain cells studying "drives".Have seen properly crowned,graded,drained drives that never saw a single "gravel",that not only survived 200+ years....but are still serving.Drop dead gorgeous as well,all things considered.

[Yonak Hawkins]

If you have access to limestone gravel you may want to check into it. It seems to have a way of locking in place and not washing away as readily.

[Mel Fulks]

Rich,since you have that new machine ,dig to hard pan... I don't imagine that requires much. For the size of stone I would use big stuff on bottom to cheaply take up space ,then cover with gravel. I have an area by garage door about 20 by 20 that I bought gravel for twice and previous owner had bought more than once. It needed a REAL fix. Dug to hard pan with 1/4 inch per foot slope ,put down landscape cloth ,covered with the old gravel SCREENED out and moved the dirt to a place needing some for a better look.

[Jerry Bruette]

I know a few basics about building a gravel drive and have read several articles on the topic but still have comments and questions.

1. Some folks want the drive to be three layers of varying rock with each layer 6" thick; that won't happen. I am not trying to build a road to Athens. Is 4" a reasonable depth for each layer?
​Around here the first layer would be what we call breaker run, probably 6' thick. It's limestone that's crushed to that size. Being crushed stone it locks together tightly.

2. Concerning layers, many say 3" - 4" rock for the bottom layer. Will 209 stone suffice? I am not quite sure what it is, but the quarry a couple miles from the farm has it.
Don't know what 209 stone is but see answer to #1.

3. I am likely going to cut into the hillside to bury the drive or only have it above the grass a few inches. Is there a reason to have it a foot above the area around it?
If you're going to plow snow off of it I'd build it up above the adjacent grade. Gives you somewhere to plow the snow.

4. Is 12' wide sufficient?
Depends on the width of the underlayment cloth. Cloth might be 12' and I'd go a little wider than that.

5. Everyone seems to recommend an underlayment cloth in heavy clay soil, which this is, but do you also recommend having an "edge" on the driveway such as railroad ties? This drive will be about 300' long. That's a lot of ties.
​Here again are you going to plow the drive? Nowhere to push the snow if you have an 8" tie sticking up above the drive. If you crown the drive some I don't see a need for the ties, just taper the edges. The ties could become a big maintenance issue in the future when the start to rot, and they will rot.

6. Some dealers want to quote in cubic yards and others in tons.....how does one calculate apples to oranges?
Good question, I've asked the local dealer for the ton/yard conversion only to be more confused. What if it rained yesterday and the material is wet?

Thanks.

[Stew Hagerty]

Make your first layer using #304, which is a mix of #4 & #10 stone. It's very good as a base, even in muddy areas. This should be 6" deep.
Then use #57 as your middle layer. 4" thick is just fine for this layer.
Top it all off with a 4" layer of Crusher Run. It's a mix of stone & stone dust. This material compacts extremely well and will provide an excellent driving surface.

[Steve Peterson]

I am out on the left coast where we don't get much snow, just rain. Also, the topsoil is typically about 6-12" thick before hitting slate. You are on semi-solid rock by the time you grade it flat. Most people just throw down about 4" of crushed rock and spread it around. Add a bit more in the spots that need it after a year or two.

Steve

[Rick Moyer]

Already some good advice. A cubic yard of average limestone is about a ton. Base and drainage are key for a good sustainable roadbed. Will you be needing deliveries in large heavy trucks? Cars don't do too much damage but a big truck is ten times heavier (or more).

[Rich Riddle]

About the biggest equipment that will likely travel the road will be 8000 pounds.

[Ronald Blue]

Sounds like you have lot's of opinions and some good advice but some impractical suggestions as well. What type of aggregate is available to you? Dig the turf off and lay down a base of larger rock. 6" deep is plenty for the weight you are anticipating. I don't know the number but it's going to average about 3" approxamately. If you have limestone available it is a good choice. I could see you only having granite or river gravel available too. If you do have limestone available a good topcoat around here is called CA-6. It's a mix of finer and courser up to maybe an inch. It grades easily and packs well. The drawback to limestone is it breaks down to dust and basically dissolves away over time. So you might have to add a load or two every 2-3 years depending on traffic. I know snow isn't a common issue for you but it can be easy to plow rock off pushing snow as well. I also don't see you dealing with a lot of frost in the ground to cause issues in the spring. Twelve feet in width should be fine unless your going to be bringing semi's in and out. Curves might need a little extra width. It should go smoothly. Keep us posted.