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By: Joe Czaszynski, April 2020

If a building owner has reoccurring leaks at the top floor or roof, it may be a sign that a roof replacement is required in the very near future. That may sound presumptive without further context; however, a proactive approach to repair work on a building is the best way to avoid costly repairs and premature replacement. A leaky roof often requires interior and exterior repairs.

The key to being proactive with a roof system is to have regular inspections performed by a roof professional. If a qualified engineer/architect is performing frequent roof inspections, he or she can identify conditions in a timely manner that can be easily fixed and in-turn prolong the life span of a roof.  The majority of owners and property managers do not see their roof(s) up-close very often, or even at all. Simple issues, such as debris blocking a drain, leader, or gutter, can lead to water infiltration, water ponding, and premature system failures when left unaddressed. Larger related system issues that are unseen, such as brick deterioration, rust accumulation, or failed waterproofing, can lead to water infiltration and severe damage. Although roof membrane system replacement is eventually required on all buildings, unaddressed maintenance and conditions will lead to roof replacement much sooner.

Depending on the existing roof system, there are many indicative signs for when replacement is needed. No matter what existing roof system is present, age is a good indicator of when replacement should be considered. Typical low slope and steep slope roof systems can last anywhere from 10 to 25 years. Some roof membrane systems may extend beyond 25 years, depending on the expected lifespan. Signs of wear and deterioration are evident when a system reaches its life expectancy, at which time, replacement of the roof system is recommended.


Different types of roof systems typically have issues. Steep slope roofs typically utilize asphalt shingles, clay or concrete tiles, slate, and metal with standing seams. The most common steep slope system, asphalt shingles, have tell-tale signs such as granule loss and/or missing tabs, that signify replacement should be considered.

There are a variety of membrane types on low slope roofs, such as SBS (styrene butadiene styrene) modified bitumen systems, EPDM  (Ethylene Propylene Diene Monomer), PVC (Polyvinyl Chloride), TPO (Thermaplastic Polyolefin); there are also fluid applied coatings, such as PMMA (Poly-Methylmethacrylate), PUMA (Polyurethane-Methylmethacrylate) and others. All but the fluid applied coating systems have seams, which can be vulnerable to breech if the seams are not properly installed or perhaps sustain damage during the expected service life. In our experience, open seams tend to be the most common reason for water infiltration. Wear on the roof surface, damaged or open penetration flashings, or failed sealant are all accompanying factors that culminate into system component failure. The above-mentioned work can be repaired, but if similar failures or deficiencies are likely to occur in the near future, a proactive roof replacement project is the best option, as it will save money on useless endless repairs.

Conventional SBS and APP modified bitumen roof systems are not meant to withstand ponding water, which is typically defined industry-wide, as moisture that does not evaporate within 48 hours of no rainfall. Ponding water that is present on a modified bitumen system for more than 48 hours can lead to vegetative growth and depressions in the membrane system. Long term presence of moisture is likely to cause water infiltration at the seams within the roof system, and possible damage to the insulation and the substrate below. Ponding water is usually the result of an inadequate slope to the drain(s) which often stems from a poor drainage layout.

The addition of rooftop overburden systems on an existing roof can also lead to early roof replacement. Roofs with accessories like photovoltaic (solar panel) systems, HVAC systems, dunnage, and new access points, may  require more maintenance and repair due to foot traffic and post construction roof system modifications.

The upfront cost for a comprehensive roof system replacement is substantial and there is no way of getting around that. Roof repairs and regular inspections should be performed on a regular seasonal basis, at minimum, to prolong the expected lifespan; proactive maintenance and repairs can provide building owner(s) time to financially plan for the capital improvements. Who knows, forward thinking maintenance and repairs may provide an owner a few extra years beyond the anticipated lifespan.

If you think your building requires roof repair or replacement work, feel free to call or email us with your questions at (973) 706-8584 or tkhoudary@sullivanengineeringllc.com.

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About Sullivan Engineering, A Rimkus Company

Sullivan Engineering provides high-quality building envelope restoration and compliance solutions.

We partner with facilities managers and account executives to provide technical expertise and project management for building envelope restoration, compliance, and maintenance.

Our solutions reduce the overall building life cycle maintenance costs by creating long-lasting, high-quality work for years to come.


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