Common Roofing Problem: Ponding Water
No one roofing system or type of facility is more susceptible than another; ponding water is a universal problem. The primary source of ponding water is lack of roof slope in the system. The absence of roof slope isn’t the only poor design decision that results in drainage problems; others include:
- A scupper or drainage system that has no crickets or saddles.
- A curb that obstructs the drainage path.
- An inadequate drain sump.
- Clogged drains and gutters.
If there’s been a leak that caused the deck to corrode or insulation to compress, the deck or insulation might sag enabling water to collect. Another source of this deflection is the weight of rooftop equipment.
Water that doesn’t drain from the roof properly provides an opportunity for microbial growth. It also accelerates deterioration. Manufacturer requirements state that water should not stand on the roof for more than 48 hours because it reacts with the membrane and causes premature aging. It also creates slip and fall hazards, adds weight to the roof that structural members and the roof deck may not have been designed to hold, and attracts environmental debris (e.g. sprouting seeds). Additionally, severe leaks are probable.
Inspect your roof. Perform visual inspections after storms to ensure drainage has not been obstructed with environmental debris. Call in a licensed roofing contractor for regular annual inspections and schedule routine maintenance. Regular cleaning and repairs will identify potential problems early and ensure proper drainage.
Improve the roof’s design. Strategies include pouring tapered lightweight concrete, adding tapered insulation, or installing additional drainage mechanisms (e.g. crickets).