This new EPDM roof will one day have contractors asking, "Should I tear off? Or should I repair?" Thanks to technology, the answer will more often involve restoration.

Good roofing practice has always been to tear off an existing roof to the deck and replace it with new material, but that is beginning to change. The age has come where tearing off an older roof may not be the best choice on behalf of the building owner or the environment.

Sustainability, the latest buzzword in the commercial roofing industry, is fueling the desire of building owners to minimize resource consumption and also reduce landfill usage. The advent of several forensic diagnostic tools available to roof consultants is consistent with the trend of minimizing waste and extending the life of existing materials. Now, consultants can provide their customers with multiple options when their roof systems need repair.

Consultants are increasingly turning to technologies such as infrared and nuclear moisture scans, moisture meters, fastener pull-out equipment, insulation density tests, and GPS tools to help determine the best option for an aged roof. When these tools are used in conjunction with thorough energy analyses and life-cycle costing, the best solution becomes clear. With these technologies, consultants have the upper hand in providing clients with the most logical and economical roofing solutions for their aging roof systems.

All of these testing methods and technologies could not have come at a better time. Over the past 45 years, ethylene propylene diene monomer (EPDM) single-ply roof systems have grown considerably in market share compared with their modified bitumen and built-up competition. As a result, there are many aging EPDM roofs, and consultants will be faced with the task of providing cost-effective, durable solutions to keep them in proper working order without tearing off the existing roofs.

Several factors impact a consultant's decision regarding a roof system at the end of its useful life. Thermal bridging, proper drainage, R-value, surface color, wind uplift, and hail resistance are all important factors to consider. When everything is taken into account, consultants are faced with two primary choices, besides a complete tear off and replacement, when addressing an aged EPDM roof — restoration and recover.

In this month's issue, we will focus on EPDM restoration. Part 2 of the two-part series, in the April issue of RSI Magazine, will highlight EPDM recovery.

EPDM restoration

Because of today's technology and environmental concerns, consultants may justifiably choose to restore an existing roof without the need for replacement or full recover. Restoring single-ply systems can be the most prudent thing to do for a building owner. The life cycle should not be counted until the usable life of the roof is really over, and many single-ply systems are providing serviceable life well beyond 20 years.

When considering restoration options, the type of membrane must be taken into account. If a building owner originally selected an economical membrane, such as a 45-mil sheet, then the restoration process may require a roof coating to extend the life of the sheet in addition to stripping in the seams and redoing the flashings.

Over the past several years, coating technology has advanced significantly. Today's coatings are considered a viable solution to an aged but not failing system. Many roof coatings feature warranties that cover the products' reflectivity and performance, providing buildings and their owners with years of protection and extended service life.

For buildings that feature a thicker, more premium membrane, such as a 60-, 75- or 90-mil sheet, restoration procedures may only have to address the seams and flashings. Coatings can still be used to enhance reflectivity, but in many instances, they are not necessary to enhance the field membrane's performance. The old adage of "pay me now or pay me later" holds true when it comes to the thickness of some roofing materials, and it is encouraging that building owners are increasingly recognizing the benefits of thicker membranes.