Important Factors for Managers to Consider in Roofing Dilemmatest

By Eric Hasselbusch

May 2015

Repair. If a roof system has been properly designed and installed, the most cost-effective option is almost always to maintain the roof, make timely repairs and plan for future replacement. If the roof system is in good condition with limited wet insulation and substrate issues, repairing the roof is a viable option.

Managers are often surprised by the amount of damage that can result from roof traffic and newly added penetrations if crews do not identify and repair them in a timely manner. Training external contractors and internal staff to properly care for roofs while performing rooftop work can significantly reduce ongoing roof damage.

Recover. Leaving an existing roof in place and recovering it with a new roof offers many advantages. It is a lower-cost option than replacement, since it does not require removal. The project’s duration also is reduced, limiting construction risk to the facility and operations. The process of recovering a roof typically is less likely to result in water or debris entering a facility. Finally, as sustainability continues to be a high priority, recovery results in less construction material entering the landfill.

Based on these factors, it is easy to decide to recover. But managers must consider several issues before selecting a recover as a viable option:

• How much moisture does the roof system hold? If 40 percent or more of the roof insulation is wet, replacement is typically the most cost-effective option.
• Will it be cost-prohibitive to modify rooftop equipment and flashings to meet current building codes?
• Can the existing structure support the additional weight of a second roof?
• How many roofs are in place? Building codes allow for two roofs before replacement is required.
• Do insurance restrictions affect the decision?

Replace. If a manager opts to replace a roof, most likely it is due to a history of roof leaks and moisture in the roof system. In some cases, a roof might have been leaking for years. Moisture trapped in a roof requires replacing the wet insulation and can result in an undetected damaged roof deck and structural components. If a roof is recovered without removing the trapped moisture, it can result in reduced insulation value and long-term damage to the roof deck and other system components.

Fine-tuning the decision

Finally, insurance requirements or building code can affect the decision. Insurance carriers may limit the amount of insulation that can be added to a recovered roof impacting the ability to meet energy code. If the building code requires adding insulation to the roof, managers must be sure rooftop equipment and flashing heights allow the additional insulation without the need to raise them.

Raising equipment and flashing heights is costly and in some cases is required to receive a manufacturer’s warranty. In some situations, if adding insulation to meet building codes requires extensive modifications to adjacent roof-related components, such as door thresholds and masonry through-wall flashings, the manager can request a variance from authorities having jurisdiction or the property insurance carrier. The most comprehensive approach is to completely remove the existing roof, enabling inspectors to identify all hidden issues prior to replacement.

No hard and fast rule exists when it comes to deciding whether to repair, recover or replace a roof. Managers and their organizations do not have unlimited budgets, so it is typically a trade-off between risk, performance and cost. Having accurate and objective information on a roof’s condition and the accompanying risk provides the foundation for managers to make the best possible decision based on their specific situation.

Eric Hasselbusch — ehasselbusch@benchmark-inc.com — is an account manager with Benchmark Inc., a roof and pavement consulting company with headquarters in Cedar Rapids, Iowa.