Asphalt driveway help

[Tom P]

Any tips or advice to get a " good " quality job done by the contractor we pick. Also, watching Hometime a couple of years ago, they talked about a base coat that has more aggregate. Then they put on the final "fine" coat that has almost no large aggregate. They said alot of asphalt contractors use the base coat only for a driveway because it is cheaper and they make more profit. Can anyone tell me what are those 2 grades the coarse and the fine final grade I need so we can talk apples to apples with the guy who will lay it and we can put it in writting in the contract. Any help or things to look out for will help. -----P. S. What is the standard thickness and what would be the optimum thickness for longevity. Thanks.

[Boatnut]

Tom,
I'm a semi retired concrete contractor. My knowledge of asphalt is somewhat limited. I do know that the larger the aggregate the stronger the material is, whether it's concrete or asphalt. Most commercial parking lots consist of a good base course of stone , then a 3 to 4" layer of the larger aggregate asphalt followed by a 2 inch "topping course" of the finer stuff. Most residential drives get just one course of asphalt often only 2" thick. Not enough in my opinion.
I do know that the residential contractors are often at the mercy of whatever the batch plant is producing that day. If they are batching material for a big highway job somewhere, then often that's all they can get.
Have you considered concrete? More expensive in the short run but cheaper in the long run. No black stuff to track in the house and not hot to walk on. You won't be seal coating it every year either.

[Bitman]

You can get by with 2" of asphalt in a private drive if you have a good 6" aggregate base underneath it. But for optimum life, a 1-1/2"
asphalt base with a 1-1/2" top course over 6" agg. base should last you a lifetime if agg. base is properly compacted. Your asphalt drive is only going to be as strong as your aggregate base. No need to sealcoat drive unless you have older vehicles leaking on drive or you like the black color. Asphalt will fade to white or gray over the years as the asphalt itself gets worn off the top of the stones.
Hope this helps, any other questions, feel free to e-mail me.

["COMA"]

I lived on the back of a asphalt paver for four years. My experience with drive ways would have them lay at least 4 1/2" of base mix on a compacted and smooth subgrade. The base mix should have a good amount of 1" - 2" road stone in it. Also make sure the mix has a oily look to it. Not much oil in the mix and it will fall apart a lot quicker. The oils hold it all together. This 4 1/2" will compact down to 3" thick. Then spray down a good layer of tack oil on top of the base lift. Then put on 2 1/2" final lift of a finer mix say 1/4 - 1/2" peat rock and fine sand mixture. Again mix should look a little oily wet. Not bone dry. This final lift will only compact down a 1/2" maybe a touch more. Leaving you with 5 inches of total thickness. Should last at least twenty years with proper seal coating applications applied every few years. Watch them closely for thickness to make sure you get your moneys worth. Try not to breath the asphalt smoke. It is toxic. If there is not much fall to the area being paved or it borders the house check for drainage with a 4' level sliiding it along to make sure you have water drainage away from the house and off the driveway. A big water hole in front of the garage is not good. Good luck. "COMA"

[fatboy]

bitman is right. also tell the contractor that you want them to proof roll the stone base before they lay the base course. this will be done by driving a heavy piece of equipment like a backhoe over the stone base with a full bucket of stone etc... over it. if you see any areas that seem to pump (move up and down under the weight of the tires)then you need to have them remove this area of stone and put stone in deeper in that area.

[snoo]

I am a bit confused....is it necessary or at least a good idea to have your driveway sealcoated? Previous post says it isn't yet you say to do it every 5 yrs or so. I ask because my driveway has been done 3 years ago and I have had sealcoaters working in the neighborhood stop and inquire if I want it done. In fact one stopped yesterday and at first quoted me $850 and then dropped the price to $700. (I have quite a long driveway) I am very leary of these guys.

["COMA"]

When the asphalt does not look black anymore it has lost a lot of its oil and will start to crack apart. This is a good time to seal or slurry coat to seal it back up before it starts to crack apart. You don't have to use the sealcoating method that requies small 1/4" road stone with the slurry. The slurry coating itself is usally enough for a drive way. This driveway sealant came be purchased at most big hardware stores and applied with a squeege yourself fairly inexpensively.

[fatboy]

also if you live in a cold climate the seal-coat will help from getting moisture in the little cracks and the freeze/thaw will not do damage. once again remember that the asphalt is only as good as the stone base underneth it. if the base is not compacted hard enough it will allow the asphalt to move up and down flexing when you drive over it(flexing leads to cracks)when these cracks fill with water and the temp. is moving above and below freezing the frozen water in the cracks keeps pushing the crack apart.

[Tom P]

Thanks for the help to all, and to COMA, that is exactly what I was looking for.

[PMR]

If you live in a cold state (I'm in MN) then pay special attention to the part of the driveway cloest to the house. Assuming you have a foundation under your front garage floor the backfill trench outside of the foundation can be prone to frost heave. Keep water away from it with gutters/downspouts and proper grading but if you've got the chance and have had heave problems in the past have the contractor compact granular material (sand, etc., something that doesn't expand with frost)in the backfill trench to prevent heaving in January-March when the frost is deepest.