A good roofing management program extends the life of the roof and maintains its ability to perform. Without such a program, roof leakage and property damage are likely, with repairs and replacement scheduled by crisis rather than by design.
A roofing management program starts with organized record keeping at the time of initial design. The original plans and specifications, including load capacity, code requirements, drainage, R-value of insulation, material specifications, and warranties, should be part of these records. In addition, as-built details and minutes of preconstruction conferences should be recorded. An estimate of the replacement cost of the roofing system is necessary because the roof is a depreciable asset that will eventually require replacement.
Contractual Surveys and Roof Maintenance
Managers may find it beneficial to establish a program of maintenance and inspection with a reputable local roofing contractor or qualified third-party consultant. Typically, such a contract includes inspections of the entire roof area twice each year: once in the spring and again in the fall. The contractor prepares a report on conditions, including recommendations for needed repair or maintenance work and an estimate of the cost. Upon authorization, the contractor completes the work.
Moisture Surveys of Roofing
In addition to visual surveys, moisture surveys are desirable. These might be conducted at the completion of a roofing project to confirm that the roofing system is dry and again shortly before a roofing contractor’s warranty expires. On existing roofing systems, a moisture survey should be conducted when the roofing file is compiled and then every two to five years.
There are several methods used to conduct moisture surveys, such as infrared thermography, nuclear backscatter, or electrical capacitance. Each method identifies wet insulation, but does not necessarily find the source of the moisture. Identifying the relative moisture content of each section of the roofing helps produce a relative moisture content map of the roofing. The wettest area can be selected, and a core sample (a small section of the full depth of the roof) is tested to determine the actual moisture content. An informed evaluation can then be made about the condition of the roofing and any remedial action required.
Keeping an inventory of repair materials appropriate for the roofing system in place, as part of a regular maintenance program, will facilitate quick repairs that can minimize damage.
Emergency Roofing Repairs
The best time to prepare for emergency repairs is before they are needed. Emergencies, by definition, require quick action, usually during severe weather that can cause dangerous conditions on the roof as well as inside. Electricity and water are a hazardous combination. It is important to protect occupants by closing off areas that are endangered or shutting off electrical service if necessary.
Keep a supply of basic roofing repair materials on hand. In addition, sheets of plastic film, a wet-vac, clean rags, mops, and buckets are useful to protect furnishings and remove water. Specialized products developed for emergencies include reinforced nylon tarps with threaded hose connections at the center, called ceiling water diverters. Special leak-plugging chemicals are another option to consider.
The following are some additional materials and tools to have on hand for roofing emergencies:
- bituminous mastic, appropriate for roofing type
- wet-patch mastics
- treated woven glass or burlap (for bituminous systems)
- adhesive and narrow rolls of elastomeric/plastic membrane
- duct tape
- screwdriver, sharp knife, scissors, straight claw hammer
- trowel or mastics brush for adhesives
- large-headed nails for flashing failures
- satchel to haul tools
- dry rags
- push broom
Safety first! Two people should work together. Before stepping onto the roof, check for fallen electrical lines or other dangerous situations. If the roof is so heavily loaded with water, snow, or ice that the deck could collapse, make sure occupants are evacuated.
Water may back up into flashing, pitch pockets, or wall surfaces if the membrane cannot drain freely. Examine drains first, and clear the strainers. Do not reach down into a drain pipe, as the release of a blockage may cause sudden and dangerous suction.
Leaks are sometimes associated with punctures from wind- toppled equipment. Look for signs of missing hatch covers, loose guy wires, or other clues pointing to punctures.
When necessary, use brooms, squeegees, snow shovels, pumps, or siphons to lower the water level. As the water level drops, have occupants look for interior leaks. When the leaking slows down, there may be a puncture at the perimeter of the ponded area. Shovels may damage the surface of the membrane and should be used only when snow buildup is great.
Wind-torn or displaced roofing requires battens, sandbags, concrete blocks, or other emergency ballasting to protect ever-widening damage. On steel or nailable decks, wood batten strips can be fastened directly through the membrane. Tarps or other covers may have to be applied and ballasted to seal areas where the membrane has been lost. Look for perimeter damage, because wind effects usually are most severe at the corners and perimeters of roof areas.
Obviously, these are hurried situations and repairs should be regarded as temporary only. Permanent, durable repairs should be completed as soon as conditions allow.
Wet Condition Roofing Repairs
Dry out the surface as much as possible. Even wet-patch materials have a better chance of success if surface water is removed. If necessary, dam off water flow to the damaged area by embedding wood two-by-fours in plastic cement or use sand, sandbags, portland cement, mortar mix, or lime. Dry the area with rags, a propane torch, compressed air, fans, or hot air guns. Use caution with electrical devices in wet areas.
On bituminous roofing, chip or brush debris or gravel back at least 4 inches to either side of the damaged area to receive the patch. Wire brush elastomeric surfaces to remove the oxidized layer, wipe with ether or acetone to remove surface moisture, and apply contact adhesive. On thermoplastic membranes, clean and heat weld. Do not attempt urethane patches in wet weather; plug with bituminous material until the weather allows a proper repair. With all products of elastoplastic systems, check with the materials manufacturer to ensure compatibility. Pressure-sensitive peel-and-stick patches will adhere to almost all elastoplastic surfaces.
On clean cuts or punctures, even duct tape can provide protection. Clean and dry the roofing surfaces before taping.
After an emergency is under control, record the location of the temporary repairs and schedule permanent repairs as soon as possible. If severe weather persists for weeks, the patches may have to be checked frequently and redone as necessary to protect the building.
This article is adapted from BOMI International’s course The Design, Operation, and Maintenance of Building Systems, Part I, part of the RPA and FMA designation programs. More information regarding this course or the new High-Performance certificate courses is available by calling 1-800-235-2664. Visit BOMI International’s website, www.bomi.org.