What is a pool main drain anyway? You hear this term floated around quite a bit when buying a pool. If you’re in the market for a new swimming pool or you have one already, you know what I mean. The history of the main drain is not quite what you think it is. Also, you might be surprised by why we have them on pools in the first place.
What Are Pool Main Drains?
Main drains are the holes in the floor of the pool where water is sucked back to the pump. Historically these were nothing more than a drain like the drain in your bathtub. Much like your bathtub, to prevent the pipes getting clogged grating was placed over the drain openings. However, you might be surprised to know that initially there was no suction out of pool main drains.
Pool Main Drain Origins
The first swimming pools with main drains were those built to use natural water sources. Once the water became too dirty to swim in, the water was simply drained and refilled, much like a bathtub. With the advent of chlorination for swimming pools and recirculation systems, these existing pools were adapted to suck water out of the drains, and return over the walls.
Eventually this became returns through the walls, and skimmers were added for surface debris. Throughout it all the pool main drain remained ubiquitous on all swimming pools.
Pros And Cons Of A Pool Main Drain
Fast forward to today and you’ll notice there are some swimming pools being built without main drains to avoid the suction hazard. After all, pools are not inherently safe structures. The pool main drain has the risk of becoming an entrapment hazard. That is people can be trapped on the floor of the pool by the suction force of the pump.
This has led to legislation requiring anti entrapment methods being undertaken, specific drain cover and sump design criteria, and more. One of the easy ways to eliminate suction entrapment hazard however, is to eliminate the pool main drain from the design.
For some pools this isn’t a reasonable solution. However, for most residential pools, there is almost no reason to have a main drain in the pool. You can remove water from the pool using skimmers. You can return water to the pool using floor returns or wall returns. Either way, you are able to circulate water, and you don’t need to suck water out of the pool using main drains.
Ironically enough, one of the most common reasons people want main drains is debris removal. Brushing dirt and small leaves to the main drain is an effective way to get rid of them. Or if you have a in-floor cleaning system, you know the drains are an important part of the cleaning process, and without them you will not have a clean pool.
Pool Main Drain Regulations
With any pool, you must follow industry regulations when adding or replacing a pool main drain. Pool main drains are regulated by the Virginia Graeme Baker Act, along with supplemental codes and standards. Following these codes specifically whenever working on a swimming pool, or replacing any components is the responsibility of every swimming pool professional.
Pool main drain safety is one of the easiest but often overlooked safety checks every home buyer should require their home inspectors to confirm prior to buying any house with a swimming pool.
For more information on drain grate safety, please check the CPSC guidelines and industry adaptations.
