I am in the middle of widening my drive way (because I am tired of doing the Icky shuffle or driving on the lawn)
I have dug up the sod and top-soil and re-placed it(the best grass on the property)
Now I need to get down a good base.
I am planning to dig at least 6″ down an put a layer of compacted crusher run gravel.
The under lying soil has good drainage. Lots of stone and sediment.
I live about 1000′ from the Chemung river.(southern tier NY, 36″-40″ frost line)
I will not be paving for a few years, unless I come into some money unexpectedly.
So, will I benefit from using a Geo-textile road fabric or should I just. scrape off a little more soil and put a deeper gravel bed?
Thanx in advance!
Mr T
Do not try this at home!
I am an Experienced Professional!
Replies
I would go a few inches deeper and put in a 5-6" base of #3 stone (big stuff=2-3"), and drive on it for six months to a year. If you can afford to have a small roller type compactor run on it you can forego the drive on it period. The larger stone won't won't get swallowed in the soil, and helps form a drainage plane for anything going above it. The geotextile material goes over the larger stone and is covered with 1-1 1/2" sized stone at 3-4" thickness (compacted also). If you pave with asphalt, you now have a proper subase for it. If you pour concrete you still have a better base than anything most residential builders ever put in.
Dave
Geotextile is a good idea regardless of the subbase thickness. It will prevent intermingling of the subbase and the native soil. After you excavate, lay it down on the native soil and place your subbase on top of it. If your native soils are decent, you could use a non-woven geotextile or, if you have periodic soft spots, a woven (or "road fabric") geotextile will help bridge the weak areas. Either will function as a filter between the subbase and native soils.
As for subbase material, I'd use an NYSDOT Type 2 subbase (max particle size is 2 inches with about 10% fines). This is basically crusher run (as you were proposing). There are four types of NYSDOT crusher run materials and two of them require that you use them together. Thus, I usually use one of the other two types (Type 1 or Type 2) so I don't have to have two different types of materials brought in. I'd use the Type 2 instead of Type 1 because it is smaller (2" max particle size as opposed to 3") which is better suited to your 6" lift thickness. I'd avoid using a "crushed stone" product because it doesn't have enough different sizes to really lock up. It certainly would drain well but for pavement, you need strength and crusher run will be better in that regard. The NYSDOT uses crusher run for road subbase all the time.
For subbase thickness, 6" is probably the minimum to use. More is better but for a residential driveway, you wouldn't need to go crazy. Maybe 8" would be a good thickness. When you finally do pave, have your paving contractor hit the crusher run with a vibratory roller if they have one. The vibratary action works well on the granular crusher run.