Q. I have a question about fixing concrete. My patio has cracked and settled and the step is so low I trip going into the home. How do I fix this problem? Do I remove the old patio and have a new one installed or maybe install a deck over the concrete, or can I fix the concrete and keep the old patio?
A. From your question I must assume you have only one step and that the patio has settled toward the foundation. In addition to the problem of tripping caused by the uneven step, you have the problem of rain or snowmelt water running toward the foundation wall.
If you have a crawl space or basement, the runoff water can enter the foundation, causing additional problems with mold, decay and erosion.
Water accumulating next to a foundation wall can cause serious structural damage. Adding a deck over concrete that drains toward the home does not solve the problem.
You could remove the old concrete, regrade the soils underneath to drain away from the home and then add a deck.
If you want to keep the patio, there is a process known as "slab-jacking," or "mud-jacking," to raise the settled concrete. Holes are drilled into damaged sections of the patio and a slurry of grout is pumped under the concrete slab, filling voids under the concrete slab until the grout has enough pressure to raise the slab and the step back to their original position. The drilled holes are filled with a nonshrinking concrete mixture and the patio is as good as new.
Before slab-jacking the patio, hire a professional to inspect the foundation walls next to the patio for signs of cracks or bulging. Any additional pressures against the foundation wall could cause additional damage to an already weakened structural wall.
As unlikely as this is, it's just a good idea to have a photographic report on the condition of the foundation before and after the repairs are made.
• Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home improvement questions at d.Barnett@insightbb.com.
Scripps Howard News Service