There are certain conditions under which using a patching compound and resurfacing product will result in merely a short-term fix. Under these conditions, patching the concrete prior to resurfacing or doing a decorative topping would be a waste of time and money, as the surface or topping would soon display the same characteristics as the concrete you tried to repair.

These conditions include:

• Deep, widespread cracks where settlement has occurred. This may be due the weight of large trucks, improper preparation of sub grade, erosion of sub grade, or for other reasons.

• Concrete slabs that have sunk, which may occur when the sub grade was not prepared properly. Loose dirt may have been used for the sub grade. When this dirt settles-sometimes due to sprinkler or rainwater going under the concrete- the concrete is unsupported and will be more susceptible to sinking. It is also possible that the sub grade was compacted and the concrete was subjected to extreme weight, which caused the concrete to sink.

• Concrete slabs that show obvious signs of frost heave. Frost heave is very common in cold climates. Moisture in the ground freezes and the concrete pushes upward.

• Concrete slabs that have so much spalling or pitting on the surface that is it more economical to replace the concrete rather than prepare the entire surface for resurfacing and resurfacing the concrete.