Can a Bad Seal Cause My In-Ground Pool to Leak?

Skimmer

• The skimmer of your pool is sealed with a pair of gaskets. There's one gasket behind the faceplate of the pool's interior and another behind the pool, leading to the filter. These gaskets can wear out over time, allowing water to seep through in a consistent leak. A pool can leak from several places, but the skimmer gasket is one of the more common areas to do so.

O-Ring

• Pool systems have many points of contact that need to be properly sealed in order to prevent pool leaks. One seal that can cause problems is in the filter pump basket. This is a small basket located next to a pool filter. Its cover can be removed to access and clean out the basket. The cover is sealed airtight by an O-ring seal. This rubber gasket fits around the lid of the cover; and when the cover is twisted shut, it creates a seal to prevent water leaks. If this gasket is worn, cracked or even stretched, it will cause a leak.

Plaster

• The plaster is critical to in-ground pool construction because, much as an above-ground pool's vinyl liner protects the pool walls, plaster lines the concrete structure and protects it from excessive water exposure. The plaster applied to in-ground pools lasts, on average, about 10 years but can prematurely crack at any time. This type of leak can damage the pool structure and cause significant water loss over time if left untreated. Plaster patch kits are available at most pool supply retailers; you will also need to drain the pool to complete the repair.

Test

• if you suspect a leak somewhere inside the pool itself, such as near the skimmer or an area in the plaster you think is cracked, a liquid dye test can be performed. Common areas for cracked plaster are near the ladder, skimmer and in corners of the pool. Inject some red food color with a standard turkey baster into the suspected leak areas. If the dye disappears into a crack or seal, that means there's a leak.