Benefits of Slope on a Waterproof Deck

by Cheryl Morgan

  • March 2nd, 2018 / 
  • Education

Waterproofing a deck is always a great investment: It will help keep the deck looking great and keep it safe for years. Although, no matter how much you spend on waterproofing materials, you will get significantly less life out of your deck if you do not factor in slope during the planning phase. Slope refers to the descending angle of materials that controls what direction the water will flow. Here are some reasons why slope should not be an afterthought.

Standing Water

After a rainfall, puddles will begin to form on a deck that is not properly sloped. This water may take some time before it evaporates. The longer the water takes to evaporate, the more likely it can become a breeding ground for bacteria and insects that can spread disease. Also, while you may have waterproofed the deck, water can still do damage to the materials if the deck is always riddled with puddles.

Deck Deterioration

When water has nowhere to go, it will start to seep into even the strongest waterproofing material. As the water seeps into the deck, it can cause the wood to rot. Rotting wood will eventually mildew and start to deteriorate, severely reducing the lifespan of the deck. It can also become a liability as rotting wood can be brittle, creating weak points where someone could fall through and injure themselves. Deck deterioration may not be evident, especially for decks that are too close to the ground for proper inspection. 

Property Damage

Water will always follow the path of least resistance, whether to the intended drain or to the foundation of the house. If the deck is improperly sloped (causing water to pool around the house), the water can be doing significant damage to the foundation. As time goes by, the standing water from improper slope can degrade the house’s integrity, creating cracks in the foundation and eventually causing the house to start to sink into the ground. If the foundation gets too bad, the house will suffer significant property loss, possibly becoming uninhabitable.

Proper slope can prevent all these issues. When considering slope, however, you want to make sure that the slope is not too steep. The slope should be enough that water will flow to the anticipated location while also being unnoticeable to those standing on it. This can be a very slight difference, as small as a fraction of an inch. This is why it is important to work with the manufacturer when determining proper slope. Before you consider constructing a deck, contact a Westcoat representative with any questions you may have.

Check out our video on Waterproofing a Deck