Low-slope roof systems are water-impermeable, not waterproof! Roof systems generally are not designed as or intended to service as waterproofing systems. Ponding water on a roof causes leaks, algae and fungi growth. If left unattended, roof ponds can lead to the collapse of a roof. Small ponds or puddles will usually dry out in less than 48 hours. Pay attention to ponding areas along seams, flashings and penetrations.
Roof Ponding is the excessive accumulation of water on low lying areas of a roof after rainfall. On low-slope or flat roofs, it may cause a deflection of the roof's underlying structural components.Roof Ponding can be detrimental to most roof membranes. The size of roof ponds increases over time because the weight of the water causes additional deflection of the structural membranes underneath. Eventually, the structure may not be able to carry the increased load.
The National Roofing Contractors Association suggests that no standing water remain on a roof membrane longer than 48 hours and considers ponding water on any roof unacceptable.
A common problem! HVAC companies need to do their job right. Water from air conditioners need to be routed directly to the drains.
An infrared moisture survey may reveal larger areas of wet insulation in the vicinity of the ponds.
Installing drains at the lowest point of the pond is usually the best way to fix a large ponding problem.
A self leveling product designed to fill shallow, wide ponds may be used. They are not designed to be used for large areas as your structure may not be able to support the extra weight of the cured product.