Deck/Patio Drainage For Inground Swimming Pools 101
We are frequently asked questions about deck drainage for inground pools.
Some common questions are:
- How much should an inground pool patio slope?
- Which direction should the patio slope?
- How do deck drain systems work and what types of deck drain systems are available?
We’ll tackle these questions here and hopefully give you a better understanding of how deck drains for inground pools really work.
What should I know about pool deck and patio drainage?
Pool patios should slope about one-quarter of an inch per foot, away from structures like the pool and your house. This helps keep water from washing debris into the pool. Deck drains divert water on the patio to another location, usually via strip drains (also called trench drains) or spot drains.
How Much Slope Should an Inground Pool Patio Have?
Pool patios, or pool decks as they’re also called, should slope at a rate of approximately one-quarter of an inch per foot.
So a section of patio eight feet wide for example, should have around two inches of fall.
Which Direction Should the Patio Slope?
The pool deck needs to slope away from the pool. Otherwise, water will wash debris into the pool on a regular basis…and that’s no fun. If the patio is surrounded by landscaping, it’s perfectly fine to allow the water to run directly off the patio into the softscape as long as that water has somewhere to go.
If the water becomes trapped in the area outside the patio for some reason, a french drain (12”x12” gravel filled trench) will usually remedy the problem.
If the pool patio does abut a house or other structure, there are several options:
- Have the patio fall away from the house as well as the pool forming a valley in the middle of the patio field. In this case the patio could either be “swaled” causing the water to naturally flow away from the center and off the sides
- Or a drain could be installed in the valley to carry water away from the patio.
- You could also have the patio fall all the way to the house where you would place a strip drain to collect and divert the water.
How Do Deck Drainage Systems Work and What Types are Available?
Deck drains are designed to collect water from the patio and divert it to another desired location. There are basically two types of deck drains used in most pool projects: Strip drains and Spot drains.
Strip Drains (also referred to as trench drains) are basically long, narrow grates which water trickles into then flows through the underground trough away from the patio. Strip drains are perfect to place against a house or other structure and are also commonly used in the valleys we discussed earlier.
Spot drains are typically smaller single drains that are tied together underground by PVC pipe that carries the water away from the patio. Spot drains are perfect in areas where long straight trench drains won’t work. This makes them ideal for free form patio applications.
Well, that’s it! If you have any other questions or thoughts, please feel free to share them in the comments section below.
Editor's note: This blog article was updated on March 26, 2020.