Slope of a driveway in direction of travel

[caver]

What kind of slope/grade can I have on a gravel road before it becomes a problem being too steep. I've got a trail up a hill where I would like to build a home. Trail follows what is an old logging path, I think. Road will be at least 1000' and gravel. I'm going to check some steep gravel slopes on area roads but also want experienced feedback. Snow is little to none in this area.

 

[mjw357]

Don't go steeper than 15%.

 

[Western]

I think your substrate will be the biggest factor, or rather what the ground is like. I know in SW Missouri, it is rocky as He(( and you could probably get away with what ever you want, I know thats true around Harrison Ark. south of the state line.

 

[caver]

Yeah not much soil between the proposed road and bedrock.

 

[Western]

Yeah not much soil between the proposed road and bedrock.

When I was a kid living on my grandfathers farm outside of Harrison, he would use his dozer to put in roads on the place. Some of it was so rocky, you'd think you would need to ADD dirt. Only times we had a hard time driving those roads was in the winter, but once you got down, you'd get some grip.

A far as your projected route, I would focus on the drainage. You may need a culvert here and there, especially at low switchbacks. If you get it graded or otherwise done and they put a nice a "crown" in the road, you will spot any drainage issues PDQ.

 

[DKCDKC]

My drive is 5,300 feet long - and all gravel. I have two (and too) steep hills. Parts of them probably rise 20 feet in 100, and that's a bit too much. Two-wheel drive cars spin in gravel, and washboarding is a problem. The 15 % rule is probably a good guide. Even with culverts and ditches, steep gravel drives will rut in heavy rains. I use a box blade and scraper blade routinely to touch up the drive following heavy rain or melt. I usually just leave a blade on the tractor all the time to be ready. I do find that using what we call crusher run or mixed rock and rock dust helps on hills. It holds better and packs down to slow rutting and washboarding. If you can afford it, a load of rock dust spread thinly on hills and rolled or run flat makes them last longer. Don't forget to put in water breaks on long hills, and make them gradual, not abrupt. Short deep breaks will shake your teeth out, and they're easy to tear out when you grade.

Good luck.

 

[vtsnowedin]

The fifteen percent rule is standard but the more you can keep it under that the better. Do you have the tools and knowhow to measure the grade that is there now?

 

[caver]

The fifteen percent rule is standard but the more you can keep it under that the better. Do you have the tools and knowhow to measure the grade that is there now?

Yes but my clinometer has a sticky bearing. I'll come up with something else. Many years ago in my free time I would help friends survey caves with clino and compass.

 

[caver]

My drive is 5,300 feet long - and all gravel. I have two (and too) steep hills. Parts of them probably rise 20 feet in 100, and that's a bit too much. Two-wheel drive cars spin in gravel, and washboarding is a problem. The 15 % rule is probably a good guide. Even with culverts and ditches, steep gravel drives will rut in heavy rains. I use a box blade and scraper blade routinely to touch up the drive following heavy rain or melt. I usually just leave a blade on the tractor all the time to be ready. I do find that using what we call crusher run or mixed rock and rock dust helps on hills. It holds better and packs down to slow rutting and washboarding. If you can afford it, a load of rock dust spread thinly on hills and rolled or run flat makes them last longer. Don't forget to put in water breaks on long hills, and make them gradual, not abrupt. Short deep breaks will shake your teeth out, and they're easy to tear out when you grade.

Good luck.

Thanks for the real world experience DKCDKC. My road would be maybe a 1/4 mile unless I have to pick another home location due the road being too steep.

 

[vtsnowedin]

Yes but my clinometer has a sticky bearing. I'll come up with something else. Many years ago in my free time I would help friends survey caves with clino and compass.

Out in the daylight a contractors level and survey rod are the thing but require two people. A laser level is a one man deal. Both can be rented. Or you can use a hand held sight level and a ruler OR a make shift solution is , a ten foot straight edge with a carpenters level taped to the end. Just rest the end of the straight edge on the road ahead of you and raise your end with the level until the bubble centers and measure between ground and bottom of the straight edge. All much simpler than plotting out where you are down in a cave.