Gravel Driveway using Grid products to reduce washout

[paulsharvey]

First, we need details. Length, width, terrian/topography, expectations, and budget. Pictures help some, but grade, drainage, ect don't always show well.

If this is a long drive, say, 500lf plus, there are worse options than just adding 36 tons of rock every 3 or 5 years.

 

[EddieWalker]

The most common reason for a gravel driveway to fail is that it's not thick enough. Road base rock has to be a mixture of rock in different sized with jagged edges to include fines. When packed together, it becomes solid. At a bare minimum, it needs to be 4 inches thick. In a lot of areas, it needs to be a lot thicker. If it's not thick enough, it will not lock together, and it will constantly loose material.

Second reason for failure is constantly grading it. Once done, it should never be graded again. If a pothole develops, address the pothole. Grading it removes fines, breaks up the rock and allows the fines to wash away.

The only solution for a failing gravel driveway is adding enough material to make it thick enough to lock together.

 

[paulsharvey]

Even in your link, they mention Gravel is Loose. Thats why gravel is not a good driveway material. The name of roadbase material varies around the country. Down here, we use Limerock roadbase, Kentucky it's called DGA, other places it's called crusher run, or one of Many other names; but basically it runs from powder upto 1.5-3" rocks, and 6" of it on top of a compacted, well drained subgrade, is what support most county roads around the country. Heavy truck traffic or busy roads (well over 1000 trips per day), often increase this to 10", placed in two lifts.

Once your base and drainage are on point, double application chip seal is a fairly affordable, fairly long lasting, repairable, resurfacable, sealed, driving coarse. It's not equal to 1.5" of asphalt, but it doesn't cost near as much, IF you have a contractor locally who still does chip seal. Micro pave is similar, but is typically more money, and generally used over existing asphalt or chip seal. Going even cheaper, prime and sand (heavily sand, or use screenings) will also help.

These geo blocks, they do have their place, but to a large degree, they shin at a pervious parking surface, that doesn't trigger drainage retention and/or permitting.

 

[EddieWalker]

I forgot to mention drainage. A lot of driveways that fail were never built up properly before the gravel was installed. To cut corners, or speed things up, some people rely on fabric to hold the rock in place, but this isn't a good, long-term solution. The only way to make sure the gravel isn't washed away is to have the road up higher than the water when it rains. Wide ditches are the best way to move water. The wider the better. Slow moving water is your ultimate goal with ditches. Usually this means bringing in a lot of dirt and compacting it. The cost of the dirt isn't the issue, it's the time it takes to do this that leads to it not happening. Just look at every road built by a County, City, or the State. They always build up the road so it's higher than the ditches on either side. It's very simple and effective.

 

[2manyrocks]

Grading so that water runs off the driveway surface is extremely important when dealing with a grade. If the water runs down the driveway surface instead of running into a ditch, it's going to washout. If you get a really hard rain ("gully washer"), it can wash regardless.

 

[paulsharvey]

The old time roads, step one was to cut the ditches, and roll that excess material up to create the road bed, compact, often mix with a rock or clay to stabalize the sandy material, then add more rock and/or sandy ballfield clay. Thats all assuming it's not a fat, expansive clay, or muck type material. This allows by default, your roadbase material to be higher than the invert of your ditch/swale.

Clean, washed gravel, is really only used to back fill wet areas, where you can't get compaction, or for around perf drainage pipe, or below storm structures, in wet areas.

 

[paulsharvey]

As I try to point out in each of these Many threads on gravel/rock/dirt driveways; I don't work in areas with freezing soils, so I know what I'm talking about, in my area, but what i say may be wrong in areas with frozen ground.

 

[camshawn]

I regularly walked our formality gravel driveway and would make shallow groves with my boot heel (or a shovel point) at an angle downhill to the outside before a rain storm. If we are getting the “Pineapple Express”, I go over the hill several times during The storm to make sure that water is draining off to the edges and not running strait down hill. The little troughs get silted in by the fines washing out. I keep the troughs clear and throw the fines back uphill. This has been the a very effective way to maintain our hill section. Last spring we put asphalt milling down and adjusted some grade. After lots of water and compaction it has set up quite well and there has not been the water erosion we used to get. Mostly the grade change at the top directed a lot of water away before the steep part of the hill.

 

[jyoutz]

Research rolling dips. This is the drainage answer for dirt or gravel roads.

 

[Fixastuff]

Research rolling dips. This is the drainage answer for dirt or gravel roads.

Yes. As someone who has ridden trails for a long time and made some miles of them on my own. You know you’re riding and older trail if it has water bars. The new trails are designed with smooth rolling dips, the trail holds up better and I think it’s more enjoyable also.

Unfortunately with driveways you don’t always have freedom to do the dips and don’t forget straight down is less distance and less gravel