What Is Ponding?

What Is Ponding?

Do you seem to notice that certain spots on your deck always seem to stay wet the longest after it rains or you wash your deck? This is because that particular spot is a low point in your deck’s surface, which is rarely even. This is called “ponding,” and it affects nearly every waterproofed deck around. Most of the time, ponding is more a nuisance than anything serious, but serious cases are an indicator of potentially bigger problems with your deck.

There’s a very easy way to tell whether or not you should be worried about the spots where you find ponding. When your deck gets wet, does the water stay for longer than 24 hours? If not, then you have nothing to worry about. If it does, then you may want to consider having the spot repaired.

Causes of Ponding

As stated previously, ponding is an extremely common problem, mostly because it has a wide variety of causes. Most decks contain some form of ponding due to one of these reasons:

  • Edge Metal: Edge metal is typically installed over sheet membrane or paper, creating an added thickness in the underlayment membrane. This usually means there’s just enough buildup to create ponding.
  • Not Enough Slope: Industry standard for deck sloping is 2%, or ¼” per foot of deck. Yes, this means a properly installed waterproof deck is never going to be perfectly flat. This is to force water to move towards a low point, where a drain is usually installed. However, not having enough slope won’t cause the water to migrate, and ponds will form.
  • Warped Framing: When constructing a deck out of wood, it’s perfectly normal for the material to expand and contract as it’s exposed to multiple climate changes. However, expanding material that’s nailed into place can warp, creating low points and ponds. Additionally, plywood brought in isn’t necessarily perfectly true to begin with, and these minor imperfections can expand, creating ponds.

Finding Ponding Early

What can you do to prevent ponding before it starts? The first and best thing you should do is to put water on your deck after it has been waterproofed to find any low points. You could try to find low points using a level as well, but trying to find a small low point in a deck that might be 500 square feet or more is an overwhelming task. You also shouldn’t try getting the wood wet either; wood absorbs water which can lead to fungal growth and rot.

Once the deck has been wet, you should be able to quickly spot and circle any low points. Once the deck dries, you can fill these low points with an applicator to level the surface before applying the top coats to completely finish the project.

If your deck has serious ponding issues, leading to cracks, deformation, and structural weakness, call Capital Deck & Stair Waterproofing. Our Los Angeles deck waterproofing experts have provided high-quality construction, repair, and resurfacing services for more than 30 years. We back all our work with warranties and a guarantee of quality to give you the confidence that you’ll be satisfied with your deck or we’ll do everything we can to fix it. We are even available on weekends to help you get the service you need on your schedule!

Schedule your service or get a quote today! Call Capital Deck & Stair Waterproofing at (310) 912-7737.

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