Ponding water - what's the problem?

There are many factors that can lead to problems on your commercial roof. One of the most common is one you may not have thought about. Did you know that ponded water on your commercial roof can lead to significant roof damage? Even if there are no leaks?


Flat roofs are one of most common types for commercial buildings. Strictly speaking, flat roofs aren’t actually “flat” but have only a very slight pitch. Because they aren’t as pitched as other roof types, they don’t drain as efficiently, and this can lead to the problem of ponding water.

We would define ponding water as water that accumulates on a roof and remains there for 48 hours or longer.

When ponding water develops, many problems can ensue, including:

  • Accelerated erosion and deterioration of the membrane surface
  • Premature roof system failure
  • Decrease in insulation’s thermal resistance as it’s compacted
  • Damage to roof deck
  • Potential further damage to building interior
  • Unwanted vegetation and algae growth
  • Accumulation of contaminants

Preventing ponding water is a matter of proper roof design and installation in the first place as well as proactive maintenance over the life of the roof. Fundamentally, it all boils down maintenance of the roof to prevent the issues in the first place and having the services of a knowledgeable, dependable roofing contractor when the issue occurs

PPM recommend that prevention comes in the form of a regular maintenance program to ensure that the roof is clean, clear and well maintained.  PPM can support site teams and train them in the signs that issues are developing.  We can then support with a nationwide roof and gutter cleaning program that and supports with a free quotation should repairs be necessary.

No matter what kind of roof you have, finding a good roofer to maintain it is crucial. Finding a good roofer, however, isn’t always easy and that is where a partnership with PPM can help

At PPM, our Engineers have received professional training, we carry £10m of insurances, carry out blind audits by trained firemen on both our methods of access as well as the safety of our working.  We have been chosen as the partner for regular maintenance by companies such as Spire Healthcare and Trust Ford so we are well versed in both the works, the safety and the supporting administration.

Please give us a call to see how we can help!