When a homeowner needs to replace their driveway, often they will seek out asphalt installation. There are many steps when installing asphalt, starting with the removal of previous concrete. Many homeowners are often confused and wonder why the asphalt cannot be laid over the concrete. Andersen Asphalt & Striping will share why the concrete needs to be removed before laying an asphalt driveway.
Asphalt is Best Driveway Surface
When you need to redo a driveway, asphalt is a great alternative to concrete as asphalt is faster to install, it is more weather resistance, and it is cost effective. When installing asphalt you can lay asphalt over a pre-existing concrete driveway, as long as the elevation will allow it. However, laying asphalt over concrete creates a number of challenges. There are a number of reasons why you will want to remove the concrete slab versus laying asphalt over on top of it.
Why Installing Asphalt Over Concrete is a Bad Idea
One of the first reasons why is it better to remove concrete when laying asphalt is that the nature of the two materials are greatly different. Since concrete is designed to be a strong and fairly stable material, contractors never have to worry about preparing the base. Concrete can be laid over a fairly flat ground. However, the ground is not prepared in a way to prevent sinking or shifting. This means the ground underneath the concrete can sink and or shift which is why concrete slabs will develop cracks or will crumble over time. When you lay asphalt over the concrete, the sub ground problems do not go away and now you will have to care for two different layers. One is the concrete layer and the second is the asphalt layer. If something goes wrong with either layer, the top asphalt layer suffers first. If the concrete slab is unstable, it will affect the asphalt which is why more often than not, it is better to remove the concrete slab and properly prepare the ground. If the longevity of the asphalt is compromised, it can lead to additional repair expenses. If the asphalt breaks due to that concrete slab, you will need to scrape off the asphalt and apply a new asphalt layer. However, if the upper asphalt layer was compromised due to the concrete foundation, then it only makes sense to remove the concrete. With the expense of laying asphalt, only to need to scrape everything up to do the job right, it is better to avoid the situation.
Overlay Concrete with Asphalt or Remove First?
When you have a driveway that needs to be repaired or replaced, you have two options. One is you can lay asphalt over a concrete slab. Doing it this way can help save money which will reduce the cost of the project. However, it come with risks. If the concrete slab is not sound it will compromise the top asphalt layer and even lead to additional cost. The second option is to remove the previous concrete slab and undergo the proper steps of preparing the ground for the asphalt.