Two frequent questions I get from homeowners:
- My driveway sounds hollow… is that bad?
- Sand runs out the end of my drive after it rains… is that bad?
If you have significant voids or space between the concrete and sub grade or if your drive is on a steep grade, this can certainly be “bad”. Does your drive make a thumping noise when you drive in on it? Maybe it rocks when you drive over it. Can you see between the joints? Are there visible cracks? Does it look like your driveway concrete is sliding away? Maybe the drive has even sunken down causing trip hazards. These are all signs or symptoms that you may be missing some sub grade underneath your concrete, which is quite important to the integrity of your drive.
Four to six inches of sand is placed and compacted, providing base and support for concrete when it is poured. The sand sub grade can settle if exposed to water repeatedly, causing a small space or void between the bottom of the slab and the sand. Other causes may be incorrect compaction, organic soils or lack of sand. Driveways that are on a grade are more susceptible to water erosion and settling because water runs downhill through joints and cracks. Those of you who have this problem know exactly what I mean.
How can I fix this problem in my driveway?
- Drill and fill the voids underneath the concrete (commonly referred to as mud-jacking).
- Caulk all joints and cracks with a good quality concrete caulk.
- Re direct downspouts and water that could wash out underneath.
How can I prevent this from happening to my drive?
- Caulk all cracks and joints with a good quality concrete caulk; this keeps water running over the top preventing it from getting underneath.
- Be sure that water drains away from your drive, preventing it from traveling under the slab.
- Direct downspouts away from your concrete.
- If you are installing a new drive, be sure the contractor properly compacts the correct amount of sand for your base.
Whether it’s a hollow sounding driveway or a washed out sandy mess, a reputable concrete repair company can fix it. If you have cracks in your sidewalk, patio or pool deck, concrete repair contractors can repair them. Typically, a good concrete raising contractor will have the capacity to deal with any of your concrete issues whether they raise it, repair it, or replace it.