A final set of problems commonly found during roof inspections includes damage caused by unrelated trade work, deteriorated flashings, unauthorized leak repairs, and contiguous building wall issues. Here's a closer look at each of these problems.
Many different trades perform work using the roof as a work platform. Air conditioning units should be cleaned, serviced, and recharged. Exhaust vent motors should be lubricated. Windows and clerestories on contiguous building elevations should be cleaned. Kitchen exhaust ventilators should be cleaned of grease residue.
Each trade considers its work the most important, and often ignores the importance of protecting the roof during such work. Equipment and tools may be dragged across the roof or dropped on the roof surface. Concentrated foot traffic around mechanical units or at roof access points, such as penthouse doors or ladders, can create localized roof damage.
The restricted roof access program should both educate trade workers and hold them accountable for damage during the course of their work. Both education and accountability require facility-management participation in supervising rooftop work and regularly inspecting to ensure compliance.
Roofs covered under warranty contain restrictions applicable to leak repairs. If a manufacturer's warranty covers the roof, the company should be notified, and scheduled repairs should be performed by an approved roofing contractor using materials manufactured by the same company.
Facility maintenance personnel may be unaware of these requirements, thereby causing an unapproved contractor to be hired for leak repairs. The contractor may not follow the recommended procedure and may use materials from a different vendor. The repair methodology may not only produce shoddy patchwork instead of a proper repair, but such unauthorized work may be excluded from warranty coverage and, in extreme cases, cause a valuable warranty to be voided.
Continuity of repair methodology is a crucial element in good roof maintenance. Facility managers should have a program for filing warranty claims and keep an approved roofing contractor on call to ensure proper leak repair response by an authorized firm. Otherwise, facility managers may find themselves paying for repairs unnecessarily. Consultants can be useful in negotiating warranty claims or disputes.
An industry axiom is that roofs leak at discontinuities, changes in elevation, roof edges, and penetrations. All of these conditions are integrated into the roof assembly as "flashings." Flashings are the most vulnerable components of a roof assembly and most likely to fail or require maintenance prematurely. Flashings may include sheet metal configurations around equipment, at roof edges, or expansion joints. Metal expands and contracts due to thermal conditions, and such expansion and contraction can cause separation at joints.
Flashings are a key component where distresses are often identified and therefore should get special attention during inspections.
Leaks may be caused by conditions on adjacent or contiguous building areas. Higher-level roofs may drain onto lower roofs without proper water conveyance components. Walls, windows, and through-wall flashings may permit moisture infiltration, misleading a facility manager to believe the cause is the roof.
Roof inspections should include not only the roof and roof-related components but also contiguous building features that may permit moisture infiltration into the building or roof assembly. Experienced roof consultants can conduct water tests to identify the actual source.
A major cause of premature roof replacement is failure to inspect and maintain roofs. Surprises abound during routine inspections. Only when facility managers have regular inspection programs, detailed record keeping, and a sound roof management program can they be assured of identifying and correcting minor problems before they cause major damage and expense. Routine inspections incorporated into a roof management program will pay for themselves in extended roof lives, improved performance, and lower life-cycle costs.
Edis Oliver, PE, is a principal in the Austin, Texas, office of Wiss, Janney, Elstner Associates. He has more than 40 years of experience in the construction and engineering field. Oliver can be reached at EOliver@wje.com.
Common Problems Found During Roof Inspections
Roof Inspections Spot Maintenance, Drainage, Vandalism Problems
Roof Inspections Also Spot Deteriorated Flashings, Unauthorized Leak Repairs
