Depth of gravel for a driveway - Gravel depth

[John Johnson]

I wish to lay a gravel driveway on a good sub-base, however the top of the sub-base is only 4inches below the top of the path around the house. I don't want the gravel to be level with the top of the path, so would 2-3 inches be deep enough for a gravel driveway, which will have vehicle traffic over it?

Advice please? oh... and what gravel size would be ideal for my purposes.

Thanks,

-John

[LandscapeMann]

John,
I.M.P. If you have a good existing subase, then 2-3" of 3/4" (18mm) or there about gravel size will work fine.
LM

[John Johnson]

A change of plan .....

My partner now want the gravel to BE LEVEL with the top of the concrete footpaths around the house, but seeing at the sub-base (3inch down - thats what we call the sub-base stone here in Eire) is 4 inches below the top of the footpath, would it be OK to top the sub-base with say a 1-2 inch down stone and then dress that with approx 2 inches of 10mm gravel.

[ABILITY]

Even two inches is too deep in my mind. You should be aiming for aroun 30mm of 10mm dia. gravel, otherwise will end up wadeing through it.
Bring base up to required level and compact well prior to adding gravel.

[84-1093879891]

I've been involved with a lot of gravel driveways in Ireland and the usual spec is to lay the sub-base, which should be the "inch-n-half down" rather than 3" down, to a level that's only 25-35mm below finished paving level, and then use a scattering of gravel, 25-35mm at most, to cover the sub-base.

2" of gravel is difficult to walk across and a pain to drive on. 3" is a bloody gravel trap!

[LandscapeMann]

I do agree to use the minimum thickness you can. I think the size and type of gravel has a bearing. If you using 3/4" (18mm) gravel (crushed stone?) . I would think that you would tend to "swim" a bit more in 2 " of 10mm than 2" of 18mm. But I do agree with the experts to use the least possible. Still if I needed to bring a existing grade up 2-3" with the stone that I describe below. I would not have a problem with that.

Since you are now talking about filling 4". A layer of subase material would be best topped with a thin layer of gravel as suggested by the resident experts.


I guess it is possible we are not referring to exactly the same type gravel? The 3/4" we have locally here (USA Md.) Is a very sharp chip type crushed stone that seems to have some smaller sizes mixed in but no fines, makes a resonably firm base for drives at 2-3". But that may be where the subase was not rock hard and some of the gravel gets inbedded. The smaller more rounded type gravel (pebbles?) would seem to give one more of the gravel trap effect.

When you used "inches" in your original post. I thought you might be from the USA. So i ventured a guess that my experience might be applicable.

LM

P.S.
I just re-read the gravel chapters on the main site. So I can be better informed for future posts.