Once the problem area has been located, the area must be repaired. When making roof repairs, it is important that the crew not damage the building or its surroundings. If the crew must reach the roof deck through the interior of the building, ensure that footwear is clean. As well, avoid damaging the walls when transporting materials.

The repair process will differ with the type of roofing system materials. One of the most important facets of the repair process is to identify the existing roof system so that compatible materials can be used for any repairs. If incompatible products are used, a durable repair will not be achieved and adjacent materials may be damaged.

The basic concept of repair is as follows:

• Determine extent of moisture ingression into the roof assembly.
• Remove and replace wet insulation and other damaged materials.
• Patch the membrane to return membrane to a watertight condition.
• Monitor situation for successful repair.

Some problems may require further investigation when a proper and watertight repair cannot be achieved with a simple repair. The existing conditions should be documented and a proper repair designed with assistance of engineering consultant.

• If a roof anchor or other penetration is causing problems, it may have to be removed and replaced. The problem should be documented and proper solution be designed. Re-construction may include construction of a new curb and cant strip to fit the projections.
• If the roof membrane contains definite, long cracks, ridges, or wrinkles, there is an indication of movement of the underlying materials. This nature and cause of the movement should be investigated and an appropriate solution identified. Movement in the structure supporting the roof system may require the installation of an expansion joint along the crack may be required. In cases of excessive movement in an unexpected location, consult an engineer to evaluate the soundness of the structure.

The following section details basic procedures for repairing several different roofing systems.