Can You Install Concrete Over Asphalt?

Considerations

• Pouring concrete over asphalt can be done if the asphalt base is thick enough to ensure there will be little to no movement under the concrete once poured. One of the problems with pouring over asphalt is that asphalt has a tendency to break, crumble and move much more than concrete. Over the course of time, the breakdown of the asphalt base also might cause cracking and chipping of the concrete.

Rationale

• The rationale for pouring concrete over asphalt is a reasonable one in some cases. The removal of asphalt can take considerable time and labor, resulting in an increased amount of man-hours needed to complete the project. If you are hiring a contractor to do the work, he may want to charge you a considerable amount more to remove the asphalt, forcing you to do it yourself. Installing concrete over the asphalt may save you both time and money in the short-term.

Purpose

• The purpose for which you are installing the concrete must also factor into the decision-making process when trying to determine whether or not to pour over asphalt. For instance, if you are planning on pouring a concrete foundation for a building, removal of the asphalt is a smart action to take. However, if you're simply pouring a driveway or a basketball court in the backyard, the durability of the asphalt is less of a concern or safety issue.

Construction

• Construction of the concrete structure over any asphalt base must be completed with great care to ensure the structural integrity of the project. Consider spreading a gravel base over the asphalt to provide some separation between the asphalt and the concrete. You may also need to thicken the concrete slab to further add weight to the asphalt and press it down. Always use rebar or some type of reinforcement steel to ensure that the concrete structure is as strong as possible.