Deck Slope Benefits on Waterproof Decks

When it comes to waterproofing, there are some key factors in extending the lifespan of the deck. These factors apply even before applying a waterproofing system. Putting a slope on a deck is the best way to extend its life while keeping it simple to maintain. It’s an easy process to calculate the slope and it’s important to know the reasons why one would consider sloping their deck.

When a deck is built with gapped boards, there isn’t much reason to slope the deck. The gaps in the boards will take care of water runoff and you won’t have to worry about any water being collected. Depending upon what materials you are using and if you want to direct the flow of water runoff then sloping your deck is an option to consider.

As a note, you can refer to this process as both sloping or pitching a deck. Pitching and sloping are just ways of describing the same angle, but from different directions; the pitch is a rising angle, while the slope is a descending angle. For the purpose of this post, we’ll be referring to the slope.

Reduce Ponding with Deck Slope:

The main reason to slope your deck is to reduce the chance of ponding, or water collecting on the decking. With a slope, the water is able to run off and drain sufficiently. You need to make sure that the slope is not noticeable but sufficient enough to do the job of draining. Most contractors suggest sloping the deck 1/4th- 1/8th of an inch for every foot of decking. With this slope, the difference isn’t terribly noticeable to those standing on the surface but your chance of ponding is reduced greatly. It is best to note that the slighter the incline, the more likely for water will pool at intersections and linings.


With ponding comes the chance of mildew and rotting. Even the best waterproofing can’t cope if your deck collects water all the time. Slope your deck before applying a waterproof coating, so as to prevent any chance of rot or mildew from ever happening. Depending on the height of your deck, rot can be incredibly dangerous. The last thing you want is for your decking to break while you or someone else is standing on it.

When decks that are closer to the ground rot is more difficult to detect at times. The closer to the ground your deck rests, the harder it is to see under it and check for mildew and rot. Discoloration of the wood is a good indication of water damage, which leads to rot. If you’re worried that your deck may be rotting, you may want to consult a professional to check and make sure it’s still safe to use.


It’s not a highly-considered factor, but sloping your deck and also reduce the damage to your home’s foundation. Level decks, or improperly sloped decks, have the risk of draining water towards your home. Water pooling at your foundation can cause issues, such as sinking or cracking. When sloping your deck, always be sure to slope it away from your home in order to keep any foundation issues from arising.

Once your deck is properly built and sloped, you’re ready to apply a waterproofing system. Depending on the kinds of materials you used in building your deck, your waterproofing may vary. If you have any questions regarding the needs of your deck, or how to best protect against water damage, then feel free to contact us, as we’d love to help you with all your waterproofing needs.