The success of any concrete foundation repair job depends upon the ability of the contractor who does the job. If properly executed, foundation repair can almost always be considered permanent. These conclusions are drawn from data collected during a 4 and one-half year period from some 380 residential foundation repair jobs in the Dallas, Texas, area. The data indicates that proper foundation repair techniques will always be successful provided the contractor understands the chemical and physical behavior of the local soil constituents and exhibit reasonable perseverance. As the data from the study indicates, re-dos sometimes occur. Here the contractor makes an initial repair that, for some reason or another, must be tempered, repeated or supplemented. The causes of re-dos are many. The largest factor, of course, is incompetency on the part of the repair contractor. Fortunately, this is a problem that can be eliminated by careful investigation of the firm selected to perform the work. Also, for example, assume that a foundation is adequately and proficiently prepared. Later a water leak develops and forces a saturation or washout of the bearing soil. Either instance can produce a new appearance of the foundation problem. Anytime a slab foundation requires a gross raise over approximately 4 inches the likelihood of a re-do increases. The Dallas study indicates this situation is not common, perhaps because technology permits a near-exact estimate of the shrinkage of a known configuration of grout. Under a normal raise, any error in estimating the shrinkage is insignificant- a direct percentage of the vertical grout thickness. However, such preciseness in not normally possible in situations that require extreme raises. According to the report all the re-do were ultimately 100 successful.