Ponding is the result of water collecting on certain areas of a flat roof and remaining on the roof for an extended period, particularly 24 to 48 hours. The presence of such puddles can be damaging to your roof, so roof repair must be done immediately. Remember that your roof and your home can only bear a certain weight, so any excess weight from the water can stress the roof trusses and other parts of your home. Furthermore, prolonged exposure to moisture can lead to various roofing issues.
In this article, Deschutes Roofing shares more information about roof ponding—why it happens, why you should be concerned about it and what you can do to fix the problem.
What Causes Ponding on Flat Roofing?
There are several possible reasons why roof ponding occurs on flat roofs. Below are some of the most common causes of this roof design problem:
- Faulty Installation – The thing about flat roofs is that they’re not perfectly flat. Roofers must install this type of roof on a slight pitch, which would enable positive drainage for the roof. This slope basically guides water toward the drains, preventing water from gathering on the roof’s surface.
- Inadequate Drainage – Improper installation can also result in poor drainage, which keeps rainwater from being carried off the roof. In other cases, drainage issues are caused by clogged or slow-moving drains.
- Expansion and Contraction of Building Materials – Consider the various materials that were used in constructing your home. All of these, including concrete, will slightly expand or contract when the temperature changes. Oftentimes, this does not necessarily create substantial problems. But in some cases, these thermal changes can deform certain parts of the building and cause the roof to sag — thus, creating uneven surfaces and low spots on your roof.
- Compressed Insulation – Some flat roofs are simply not designed to handle foot traffic or storage of heavy items. So when you use these roofs for such a purpose, the insulation would likely compress. The compression then creates a low spot, where water could naturally collect.
- Dips Near Roof Installations or Features – Skylights, plumbing vents and other roof features may have been installed with small dips, which allow ponding to occur and worsen over time. When incorporating such features on your roof, make sure to hire experienced roofers who can do the job properly.
Why Is Flat Roof Ponding a Serious property Problem?
Ponding water shouldn’t be on your roof for more than 48 hours once weather conditions become dry. If your roof is exposed to this beyond the acceptable period, the following situations may occur:
- Moisture will attract mold and insects
- Moss, algae and vegetation will grow on your roof
- The harmful effects of UV radiation will get worse
- The roof membrane, flashings and coatings will degrade prematurely
- The adhesives in your roofing system will get damaged, compromising its structural integrity
- Water can cause downward pressure on the roofing system, which could further lead to roof sagging or bowing
Again, make sure to address the issue immediately so that you can avoid serious damage to your roofing as well as expensive repair costs.
How Can Ponding Be Fixed?
Ponding on a flat roof is not a hopeless situation. With the help of roofing professionals, this can be fixed so that you won’t have to worry about any potential damage it might cause. Below are some of the most common strategies used to eliminate ponding on flat roofs:
- Inspect Your Roof. Call your trusted roofer and have them inspect your roof. This would allow you to discover the culprit behind the ponding and figure out the best approach to the problem.
- Fix the Slope. If your roofer finds out that your flat roof was installed without the proper slope, they may need to perform a full roof replacement. This will cost a significant amount, and it will take time to finish. However, this is usually the best way to correct an improperly sloped roof.
- Fix Structural Issues. If the ponding has resulted in structural damage to your home or building, it’s important to address the damage first. In such a case, your roofing company may need to work alongside structural engineers or architects to ensure proper planning and repairs.
- Fix Roof Drainage. There are various solutions to drainage problems. Your roofer may suggest adding a new drain or completely changing the drainage system in order to accommodate a larger volume of water. But if the problem is mostly clogging, the issue could be fixed by simply adding a better drain screen or making sure your roof is cleaned more frequently.
- Fix the Low Points on Your Roof. If your roof is correctly pitched but has developed low points due to poor installation or roof damage, your roofer might be able to correct this by focusing the repairs on the low points on your roof. For instance, they could use a flat roof puddle filler to bring these low spots back to the appropriate level.
- Perform All Other Necessary Roof Repairs. Your roofer should be able to identify the areas damaged by the ponding and repair or replace any affected materials. This could mean replacing sections of the cap sheet, which were exposed to water, or the insulation that may have compressed due to the excess weight from the water.
When it comes to roof repairs, always work with qualified and experienced roofers. This will give you peace of mind that the job will be done properly.
Get a Free Roofing Quote Today!
If you’re looking for a reputable roofing contractor, Deschutes Roofing is one of the most professional businesses in the area. We guarantee top-notch workmanship for every project we handle because we understand the importance of quality roofing for every household. Rest assured that our crew will guide and update you at every stage of the roofing process.
To request a free quote, you can dial any of the following numbers: (541) 241-5720 (Bend), (503) 967-9590 (Portland), (541) 246-6860 (Eugene), (503) 468-7663 (Lake Oswego) or (503) 928-8750 (Beaverton). You can also fill out our contact form, and we’ll get back to you as soon as possible.