Common problems with skylight leaks

Updated February 21, 2017

Skylights allow natural lighting of almost any room in your home, but if installed improperly or not maintained they can develop leaks. Skylight leaks cause numerous problems for homeowners, including serious property damage. Leaking skylights should be repaired as quickly as possible to minimise damage and prevent the leak from growing.

Mold and Mildew

Water leaking through the skylight during a heavy rain may enter the space between the roof and the interior ceiling. Insulation in this space will soak up the water, according to the experts at Inspectapedia. Mold and mildew grows easily in these dark, enclosed spaces. The growth of these fungi is exacerbated by the heat that naturally rises into the ceiling space and lack of air circulation. Mold and mildew lead to health issues and poor air quality.

Rotten Wood and Drywall

Since more water enters your home through a skylight leak every time rain falls, water damage caused by a skylight leak quickly leads to serious rot in the wooden frame around the skylight. The experts at Snow's Construction say that leaks are usually first noticed as stains on the surrounding drywall, but by the time the drywall is stained or damaged the weight bearing ceiling beams may be rotting.

Floor Damage

Falling water accumulates on the floor beneath a skylight leak, especially if the leak is caused by a crack in the skylight's glass or plastic. Even if you mop up the puddled water after each rainfall, some moisture will make its way under the flooring and into the subflooring. According to the experts at The Tile Doctor website, water damaged wooden subflooring will become soft and may rot or mildew.


Although not as serious and damaging as the water that leaks when a skylight is not sealed correctly, air drafts increase your heating or cooling bills. If a skylight is cracked or broken enough for you to feel a noticeable air draft, it should be repaired immediately, says the Snow's Construction website. Insects and debris may also enter the home through a skylight leak of this size.

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Jessica Kolifrath is a competent copywriter who has been writing professionally since 2008. She is based in the Atlanta area but travels around the Southeastern United States regularly. She currently holds an associate degree in psychology and is pursuing a bachelor's degree in the field.