Many early roof problems are actually flashing problems. Often, repairing the flashings or providing new flashings is all that is needed to make the roof watertight again. Most flashing problems result from inadequate flashing design or faulty construction. Many flashing problems can be reduced or eliminated by careful examination by competent inspectors during roof installation, and by regularly scheduled inspection and maintenance.

In many instances, leaks occur at flashings where there are no flashing defects. These leaks may be the result of open joints in a masonry wall or coping cap, which permits water to enter behind the flashings and into the building. This problem may be eliminated by “through-wall” flashings.

Assessing hail damage is often accomplished by a roof inspection, which usually occurs several days to several months after the hail event. Determination of whether hail actually fell at a site can be made through statements and weather reports. Inspection of thin, aluminum fixtures helps verify hail impact.

Traditionally flat roofs would use a tar and gravel based surface which, as long as there was no pooling of water, was sufficient to prevent penetration. However, these surfaces would tend to fail in colder climates, where ice dams and the like could block the flow of water. Similarly, they tend to be sensitive to sagging of the roof reversing the subtle grading of the surface.

Modern flat roofs tend to use a continuous membrane covering which can better resist pools of standing water. These membranes are applied as a continuous sheet where possible, though sealants and adhesives are available to allow for bonding multiple sheets and dealing with structures penetrating the roof surface. Far more expensive flat roof options include sealed metal roofs using copper or tin. These are soldered interlocking systems of metal panels.