Why not to seal your driveway!

Is sealing your driveway worth the time, effort and expense.

For a homeowner in my opinion "No"

Sealing companies will tell you that it protects your driveway from:

  • Water penetration
  • UV rays
  • Weather
  • Chemicals

1. If a driveway is installed with the proper pitch ( 1 inch for every 8 feet) water should drain off your driveway. The asphalt emulsion that binds the stones and sand together is not water soluble and will not wash away.

2. UV rays do break down asphalt. If you look  closely at asphalt what do you see? Depending on how old the asphalt is you will see varying sizes of stone and sand and asphalt emultion that binds all of this together. Class II asphalt has only 5.8% - 5.9 % asphalt emulation in it. When the asphalt is brand new the stones and sand have a thin coating of asphalt, that is why fresh asphalt is so black.  As it is exposed to traffic and UV rays it breaks down. I don't know how driveway sealer which is made of asphalt emulsion protects the asphalt under it. What ends up happening is the sealer breaks down over time becomes faded and cracks or wears off, hence leading to another coat of sealer being applied. It is like an annuity for sealing companies. Keeps you coming back every two years or so. 

3. Weather is driveways biggest enemy, especially frost and thaw cycles. Driveway seal cannot stop Mother Nature. In late winter early spring the asphalt pavement heaves with the frost and cracks open. When the asphalt gets older and more brittle it cracks more leading to failure. Unfortunately the driveway sealers do not have the ability to span these cracks. 

4. Chemicals, some chemicals can damage asphalt, especially petroleum products. At the least they stain the asphalt and over an extended period they break down the bond between the asphalt emultion and the aggregate. So if you have a car that leaks oil all the time, operate a gas station, convenience store or auto parts store, I would recommend driveway sealer to protect the pavement, but for the a homeowner I would not.

If sealing really extends a paved surfaces life, then why does the State of Conneticut and the local municipalities not seal their roads or parking lots ?? Hummm...