I just did this exact thing. I don't remember the rock size (#4 maybe?), but the base was bigger stone like what is shown in the pic of "surge" stone. I then went back with #57. I poured a little bit of #9's in one area over the 57's and that made it even smoother. I think with a little time and traffic, the 57's will be good, but it they are a little hard to walk on, you could put a light amount of smaller #9's to lock the 57's in place even more.
Over all, I'm very happy with the fabric, "surge" stone, and #57's. I just wish the rest of my driveway was done this way as it's a nasty mess right now, and the drive going to my shop is great.
Your guy did a nice job cutting out the driveway.
It all depends in the cbr of the soil. That reddish clay seems to be fairly solid even though saturated.
Short answer-
- Yes fabric although not necessary.
- You dont want 57's.(solely)
- Surge stone (vdot #3) for construction traffic min of 4" for some strength
- if a small garage and not much strength needed for lots of big trucks/forklift trips then install vdot 21a stone now, or once your subgrade dries out.
- Finish with vdot 21a for smooth driving surface after Construction
- if you cant wait for it to dry then fabric and #3's and choke it up with some 21a on top just enough to get 3's to start to lock up.
Long answer
So its cut 4 to 8 inches deep. I assume this means the grade of the dirt (subgrade) and its current cross slope is the way the road will be only you are 6 or 8 inches off of finish grade? So you will install your section (depth) of driveway and you will be back filling on the edges that are only cut 4 to 5 inches since your driveway (section) is 6 or 8 deep.
If it were an average dry summer you could probably get away with fabric and 4" of vdot 21a and be solid as a rock with weight rolling over the stone daily keeping in nice and tight.
If you are building now or spring probably best to shoot for an 7 inch section of stone.
Install your fabric and 4 or 5" of vdot #3 stone then choke it up with a skim coat of 21a. With your dimensions of 420sy you have roughly 25 tons per inch installed of material. So for stone and delivery to you ?? $20 ?? Per ton you are $500 per inch of stone. Rough rough number.
This will have you fairly solid for average type construction traffic and allow you to be below your finish grade elevation.
That way once done you can grade the 3s and 21a mix flat and smooth and install 1 to 2 inches of fresh 21a over it and it will be good.
You dont want to have subgrade too high because as you add this stone your driveway becomes elevated from existing grade and requires fair amount of backfill.
With it going left to right I imagine you will want to keep that water flowing as it does left to right. If you raise the driveway on the high side you cant get the water to sheet flow across driveway. It will run down the driveway
Sent from my SM-G960U using Tapatalk