Ponding water effects in flat roofs with poor slope designs and ALCHIMICA’s polyurethane waterproofing system solution.

In flat roofs that display poor construction and design it is rather usual to face the phenomenon of standing water. As when a flat roof has no inclined slopes and drainage issues, the water can easily remain for extended amounts of time and cause the ponding water effect.

Water ponding is defined by the US National Roofing Contractor Association as “water that remains on a roof surface longer than 48 hours after the termination of the most recent rain event”.

This phenomenon may cause long term water leakage issues and the need for costly repairs. Moreover, the negative effects can affect the longevity of the roof substrate when more leaks appear and lead to concrete corrosion but also cause the damage of the existing applied roof waterproofing system.

Liquid applied waterproofing systems can be effective solution to proactively prevent this kind of problems but they are also considered as a great solution for post-repairment actions. Liquid applied waterproofing membranes with high ponding water-resistance are capable to remain bonded with great adhesion to the substrate providing a great protection especially when puddles are being formed on the roof due to poor slope design. One way to test if the existing applied membrane keeps its adhesion abilities is to press it on the ponding areas.

Without proper ponding water resistance properties, a waterproofing membrane will start blistering and peeling, leading to the roof system deterioration.

Our HYPERDESMO® waterproofing membranes hold excellent water resistance properties with zero water swelling rate, being elastomeric with high UV, chemical and mechanical resistance and they protect roofs from harsh environmental conditions.