You can add more natural light to any room when a skylight does its job properly, but it may seem like more trouble than it's worth if it starts to leak. Fortunately, most leaky skylight problems are easily repaired before they cause any lasting damage.

Common Causes

  • Skylights that open sometimes leak if they aren't fully closed or if the rubber seal is broken or damaged.

  • Condensation can collect on the underside of the glass during cold weather. This isn't a true leak, just dripping condensation.

  • The flashing around the exterior of the skylight may be damaged and require replacement.

  • The interior caulking around the skylight may need repair.

Locate the Leak

If dripping water is your first indication of a leak, you'll need to find where the water is coming from. If there's visible condensation or a damaged seal, you won't have to look far to find the source of the leak.

Begin with an internal inspection of the sunlight. Look for damp areas around the perimeter of the skylight. If the caulked seal isn't visibly damaged on the inside of the house in the location of the leak, the damage is likely up on the roof.

Repairing Inside Problems

Damage to the seal inside the house is best handled by an interior contractor or a window installer. They can scrape away the old caulk and replace it with the new. The contractor can also repair a damaged rubber seal around the skylight if it opens. Condensation issues generally are caused by poor window insulation, so you may need to upgrade your skylight for your climate. Another option is to fill in the ceiling between the joists and the skylight with foam insulation.

Rooftop Damage

Although you can climb on the roof to check for damage, the process does raise safety concerns and you may unknowingly damage your roof. A better option is to call in a roofing contractor with expertise on residential skylights. Chances are the flashing or exterior caulk has suffered damage. Even a pinhole in the flashing or caulk can lead to an annoying leak.

The roofer like one from will scrape out and replace the caulk before replacing any damaged flashing. Step flashing, which locks into the neighboring shingles, provides a watertight seal. He may also install a barrier upslope from the skylight. The barrier routes water away from the skylight when it rains, so the flashing caulk aren't exposed to as much moisture.

You don't have to live with a leaking skylight. Getting it fixed promptly can prevent more damage to your home, such as sagging ceilings, damaged drywall, or mold issues.