Thanks to the help in this thread, we’re happily and comfortably moving ahead with a central air install. Next project: paving the driveway.
The driveway has an 1823 sq. foot landing pad (the area in front of the garage with space for an extra couple cars). From there, it’s about 400’ to the street. There is a very small hill in the middle (street side being the lower end; nothing you’d need 4WD for; momentum gets you up and over if there’s a small amount of snow), and an 80 degree turn near the end. Right now it’s got a bed of item 4 that is in dire need of redoing (some muddy areas, especially at the curve and end; the rest is very thin from winter plowing). The dirt under it is clay and crap—the soil you find in the NYC region.
Like with a/c, I have no idea what to ask or what to expect. And like a/c, I understand that a tremendous amount depends on local conditions—but there are still minimums out there, and basic questions to evaluate the differences between contractors, no? Also, how long should I expect from a warranty/guarantee? One year? Five? Clearly it will eventually crack, and clearly we’ll need to sealcoat it (annually? Bi-annually?), but I’m wondering what to expect the contractors to say about standing behind their work.
Are you putting down concrete or asphalt? In either case, proper underlying material is critical, as is compaction of the subsoil. An asphalt drive should be a minimum 4" thick, and the delivery temperature should be around 180F.
Concrete should have reinforcing mesh that is set on ‘chairs’ that raise it to about the middle of the slab: you don’t want the mesh contacting the earth or air, as it will eventually rust and create voids in the concrete. The ‘slump’ of the concrete should probably be no more than 4", but I’m hazy on that at this point. Also, for concrete you’ll need expansion joint material inserted at intervals (4’?). Also, concrete should not be subjected to ice melt material for the first year, or you will have spalling.
A buddy hired a contractor to pave his driveway a few years ago w/ asphalt. The driveway looked great afterwards. But a year later it looked like crap, and that’s when he discovered he got scammed… a pro told him the asphalt was cold when it was put down, and it was laid much too thin. He had to replace it.
I know that concrete does not work well for longer driveways in Upstate owing to freeze/melt and frost heaves; whether this is also true in the NYC area is something you’d need to determine locally. Hence I’d encourage going with asphalt. A suggestion: get a few estimates and check them out with the Chamber of Commerce or Better Business Bureau – most pavers are reputable and welcome this, and you’ll be warned off a fly-by-night operation that will do a shoddy job and vanish with your money.
The ground may not be hard enough yet. If you maintain gravel for several years, it will work its way into the ground and firm it up for an eventual layer of asphalt. It’s harder to clear snow from gravel since you can’t scrape it, but you don’t need to clear the snow at all until it reaches several inches. The gravel will give you better traction than a clean paved driveway.
I don’t know what the straight dope is concerning sealing driveways, but I get an impression it may be more cosmetic than anything else. It’s just a thin layer on the top surface of the driveway and won’t prevent the cracking, shifting and sinking that causes the most problems with driveways. It should keep the top surface from coming off as loose gravel though.
I would suggest asphalt too but you may need to check with your local planning or building department to see if they allow that much impervious surfacing. Storm water management is a big issue these days.
We have a similar concrete pad in front of the house but the drive to it, is short and steep covered with gravel. That doesn’t work for us as the gravel (and dirt) is always flowing down the hill. So we plan on asphalting this year as well, but our drive is short and I know we have enough acreage to offset the impervious surface.
If you can’t do asphalt you should look into something like grasscrete. This is a system that is honeycombed concrete that you plant grass in between, but it is hard enough that you can drive on it. It allows water to go through and thus most jurisdictions will allow it. Personally I would stay away from gravel if you can as it just has too many issues related to it.
It’s going to crack eventually. What sealing does is to prevent water from entering the cracks and affecting the sub-base, and also from damaging the asphalt from freeze/thaw action.
Asphalt really depends on the sub-base, which should be of the right material, well compacted, and protected from water damage. The type of soil you are building on also needs to be considered (your clay is much different than a sandy soil), as does the type of traffic you will have (the design should account for the heavy trucks and how often they will drive over the driveway). The actual thickness of the asphalt may be less than 4" with a good sub-base. The quality of materials also matters, gravel that is angular is superior to rounded gravel. Same for sand. If someone wants to pave over what you have now without installing a sub-base, send them packing.
The layout of the driveway should be properly graded also to allow for drainage.
Finally, know the location of any utilities that the driveway will pass over. If you think you may need an irrigation line or electrical conduit in the future that will pass under the driveway, put it in now.
I would consider a recycled asphalt driveway. They bring in old crushed asphalt that’s been torn up and lay it down like gravel, then compact it. It will be cheaper, and you can rip it up in places and fix it without patching. It still has many of the problems (plowing, unfinished look) that come with gravel so if that’s not your thing you might not like it, but look into it.
I have heard from several farmers that if you lay some recycled asphalt, then pour diesel on it and set it on fire, when it has finished burning it will set and be either just, or almost as good as asphalt, depending on who you speak to.
I’d have reservations about this, but does anybody know definitively whether it’s right or not? It sort of seems plausible, but also not, and I don’t have a location, or an inclination to try it out.
I would be concerned about grading and drainage from your yard, to ensure you don’t get puddles. My yard dumps into the corner of my driveway, and makes a zone that gets muddy and keeps the yard bogged.
Ooh, ooh, and the bodies, don’t forget the bodies. You’ll get tell-tale depressions as the decomp progresses. (Sorry couldn’t resist, it is the NYC area isn’t it?)
Good site that summarizes the advice posted above. For your crappy subsoil; it would probably call for a large aggregate base, glue coat, and finish with smaller aggregate top surface. Also a good tip on the timing of sealant application.
Since you don’t know what’s underneath the existing driveway, I would have them excavate at least two feet down and replace the material with NFS (non frost susceptible) material. This will help to reduce any frost heaves. The proper compaction/drainage of soil and proper temperature of the hot mix is really critical, though. If it’s too hot (burned), you’ll have just as much of a problem as if it was cold. The drivers should provide you with a ticket that tells you what the temperature was when it left the batch plant, and take the temp before they dump the mix into the spreader.
Just echoing the importance of these two items. If you ever find that you need a pass-through, and you had the foresight to put one in, you will be very glad you did it.
I used to be a construction inspector, specializing in this stuff, except it was industrial sized roads and things, not driveways.
That was all good, Chefguy, except the bold added. It should be 250f. 180 is about the temperature where your compaction is no longer having any useful effect. 300 is too warm. NY State DOT spec is max 295, or at least that’s what it was last I worked on a DOT job.[/nitpick]
Continuing with the OP:
I see you will have heavy truck traffic for deliveries, and using asphalt. Make that a 4" base course then another inch of top. Also, you will want a good 6" subbase made of -1 1/2 crushed stone. You might need more, depending on how crappy the muddy areas are. You might need considerably more. I could only tell you if I looked at it personally, because a lot of that is personal observation and experience.
Driveway sealing is a rip-off. Ask yourself how often you see the highway department or Wal-mart doing it. Never, right? If it really extended the life of anything, they certainly would, because it would be saving several hundred thousand dollars. But they don’t. Why? Because it does nothing useful. It just makes your driveway a pretty black color.
Asphalt (the black stuff that goes into it, not the finished product) dissolves in diesel fuel, and diesel fuel soaks into the groundwater. I flat-out guarantee the NY State DEC is NOT going to be happy about someone doing this.
I think of driveway sealing as the landscaping equivalent of the combover.
They sealed the parking area of the plaza across the road from my old apartment a couple of summers ago. Didn’t do anything to actually repave it or fix the two-centimetre-wide cracks in it or anything, oh no; they just wanted shiny for as cheap as they could get it.
Slight alteration to my previous post. The temperatures I specified were FAA (airport runway) specs, not NYSDOT. DOT specs were a bit looser. Stick with FAA, however, and you are still within DOT, and it’ll be good.
