When concrete deteriorates it draws and holds moisture.
Asphalt over concrete.
In fact many miles of concrete roads are paved over with asphalt every year.
Asphalt overlay is an option for some asphalt surfaces that are in disrepair but paving asphalt over concrete comes with some catches.
In addition you do have an alternative paving method that may surprise you.
If something is wrong with either of these layers it will show through the asphalt.
Laying asphalt over concrete will likely lead to this new asphalt forming cracks in the same spots that the concrete expansion joints have cracked below.
One positive aspect of installing blacktop over concrete is the concrete provides a firm base for the flexible asphalt paving.
Brick and stone pavers come in wide variety of patterns colors and textures but since they re labor intensive installing a brick paver or cobblestone driveway costs between 10 and 70 per square foot.
Laying asphalt over concrete creates two layers to worry about.
Asphalt lasts 20 25 years while concrete lasts 30 40 years.
However it is important that you understand there are potential side effects and things to watch out for when paving over concrete.
How do brick and stone pavers compare to concrete.
The truth about asphalt over concrete.
Homeowners can benefit from this whitetopping technique to reduce labor costs and time when replacing worn asphalt driveways.
Concrete paved surfaces are not compressed and compacted like asphalt is rather the concrete adheres and fills voids and irregularities with the soil and subgrade beneath it.
Unfortunately when asphalt driveways are poured over concrete resting on an unstable base the resulting asphalt pour is prone to instability.
But there are issues as you might expect.
Applying an asphalt overlay to a concrete surface is a common practice.
The unprepared sub base.
Therefore concrete is often used as a bridge over unstable ground.
This will most commonly occur during expansion and contraction due to heat and or freeze thaw cycles.
Concrete itself is very stable and strong so no matter what it is poured over the slab is going to be solid when it hardens.
To save time and money many states and municipalities use a road repair technique known as whitetopping the process of pouring concrete over asphalt rather than removing the existing asphalt.
Concrete is a great base material because it is stable and allows for excellent compaction of the asphalt above.
Does concrete provide a solid base.
An asphalt overlay is cheaper to install than replacing concrete and can provide a smooth ride over deteriorating concrete.
Blacktop can be successfully installed over concrete.
Asphalt paving contractors frequently use asphalt over concrete on interstates state highways and city streets concrete provides an excellent base for the asphalt which must have a well compacted stable foundation to yield superior results.
