Prevent Asphalt Cracking
Peter Zawisha is getting ready to put in a new asphalt drive and he wants to prevent cracks on the sides of it at his home in Hardyston, NJ. Here's what he told me:
"I'm having driveway redone.
Should I install 4x4 or 6x6 pressure treated lumber to help keep the asphalt stay tight together?
Or is this just a waste of time and money?"
Here's my sage advice for Peter:
Peter, it's a waste of money to put timbers next to the blacktop.
To prevent edge cracking of the asphalt, you simply extend the gravel base 6 to 12 inches on each side of the asphalt.
The gravel is what provides the strength to the asphalt. Timbers will simply shift in the soil.
If you just put the gravel base under where the asphalt is, then when a car parks on the edge of the pavement it presses down and OUT causing the crack. The soil is usually not strong enough to offer the lateral support needed, especially if the soil is wet.
But with the gravel at least 6 inches beyond where the asphalt ends, the asphalt will not crack because the compacted gravel is able to offer the needed LATERAL support.
Be sure you don't park on the new asphalt drive for a week or so and by all means stay away from the edges for several months.
It can take 90 days or more for new asphalt to get very hard.