Why do driveways Fall Apart?

 

I was wondering why do driveways crack and fall apart?

 Asphalt is made with sand, Stone and tar. This mixture is heated to 300 degrees and placed in a dump truck that brings it to your house.  if the asphalt is left to sit in the truck for more than a couple of hours it will cool down. Needs to be hot for proper compaction. 

 

Can the asphalt driveway be too thin? 

 

Yes. If the driveway is paved too thin by the contractor. It will not be strong enough support the weight of the vehicles that travel over it.  Also the asphalt needs to be a minimum thickness of 2 and 1/2 inches – after compaction to ensure all Air voids are closed off from the compaction process. 

 

How thick must the subgrade be to support the asphalt above it?

 

If the area that the driveway is built on is dry and free of water the answer is simple. 6 inches of stone base after compaction is more than enough for a driveway. If the area is wet you will need 10 – 12 inches of stone base after compaction.

 

I already have a driveway, can it be repaved?

 

Providing the existing asphalt surface does not have any large cracks and the areas next to the garage floor and sidewalks and the curb at the road have room for at least 2 inches of new asphalt, yes you can put a layer of new asphalt on top of your old one. 

 

Could I have the existing layer of asphalt removed? Then pave a new driveway layer on my old stone base.

 

This is almost always the wisest choice or a high-quality driveway. The old asphalt should Be removed and hauled away. In the process of doing this some of the stone will be lost. It is important to replace approximately 2 inches of additional Stone to the existing base. This will ensure a stable base and will be a smooth surface to pave on.

 

How can I be sure of how much asphalt the contractor is giving me? 

 

The only Safe Way I found is to ask for the weight slips both of the truck that delivers your asphalt. it will have the day in time the material was originally made and more importantly how much material was made. Always ask how many tons of material am I getting.