Most people believe that tree roots just get too big, raise the concrete, and cause the blocks to fail. While tree roots can contribute to defective walks, the underlying soil is most often the primary reason for sidewalk failure. Where the underlying soil type is one that shrinks and swells as moisture content changes, stronger sidewalk construction may be necessary to prevent lifting and shrinking. This might include mechanically compacting the the soil before paving. This adds to the cost but it will prolong the life of the sidewalk even when tree roots are not present.
The same soils which cause sidewalk failure also compound the problem by increasing the involvement of tree roots. These soils typically contain fine clay particles which displace oxygen in the soil causing the tree roots to grow near the surface where oxygen is available. When these surface roots grow beneath a cracked or raised sidewalk, they become established and grow in diameter, causing the sidewalk to buckle.
Chapter 721 of the Cincinnati Municipal Code requires that the maintenance and repair of sidewalks are generally the responsibility of the abutting property owner. For residential property, if the property abuts 2 or more public streets, the property owner is responsible for repairs on only 1 frontage. That frontage is determined by:
a. the parcel frontage containing the driveway;
b. where either both or neither property frontage contains a driveway, the parcel frontage upon which the street address is based.
To report a hazardous sidewalk location, contact the Department of Engineering and Transportation at 352-5292
Contact the Hamilton County Soil and Water Conservation District at 772-7645 to find out what type of soil underlies your property. If the soil is weak, then your new sidewalk, patio or driveway should be built to withstand the limitations of the soil.
Under special conditions, it may be advised by Parks and the Department of Transportation and Engineering to move the walk away from high value trees.
