How long do skylights last?

Many skylights last somewhere around 15 to 20 years, though the flashing and seals can fail sooner, especially on a roof that sees hard winters. The quality of the unit and how well it was installed and flashed make a big difference.

Can a leaking skylight be repaired instead of replaced?

Sometimes. If the glass and frame are in good shape and the leak is at the flashing or a seal, a repair may fix it. If the unit itself is failing, fogged between the panes or cracked, replacement is usually the better fix.

Should I replace my skylight when I replace my roof?

If your skylight is more than 15 years old, it usually makes sense. The roofing around the skylight is already open, so the new unit can be flashed into the new roof properly, and you avoid tearing into brand-new shingles later.

Is condensation on my skylight always a sign it's failing?

Not always. Some condensation on the inside glass can happen in a humid room on a cold winter day. But fogging between the panes of an insulated unit means the seal has failed, and constant dripping condensation can point to a poorly insulated unit or high indoor humidity.

Signs It's Time to Replace Your Skylight

By the Allabaugh Construction team · June 12, 2024 · Updated September 25, 2026

When you first put in a skylight, you probably loved it: the natural light, the feeling of open space, the way it made the room feel bigger. But years later, that same skylight can turn into a headache.

As skylights age, problems can show up that affect not only how they look but how well they keep out water and hold in heat. Leaks, condensation, drafts and cracks are all signs it might be time to replace your skylight.

Many skylights last somewhere around 15 to 20 years, but weather, installation quality and the type of skylight all affect that. Winters in Northeast Pennsylvania and New Jersey, with ice, snow and freeze-thaw cycles, are especially hard on skylight flashing and seals. Here are the signs to watch for.

1. Leaks and Water Damage

Water stains on the ceiling or walls around a skylight are one of the most obvious signs of trouble. The seal or flashing has likely failed. Left alone, the water leads to mold, damaged drywall and framing, and poorer indoor air quality. Don't wait for it to get worse. Sometimes new flashing fixes the leak, but on an older unit, replacement is often the lasting fix.

2. Fogging and Condensation

Fog or moisture trapped between the panes of an insulated skylight means the seal between them has failed, and the unit has lost much of its insulating value. That can't be wiped away or fixed from the outside. Heavy, dripping condensation on the inside glass can also point to a unit that no longer insulates well. Persistent moisture leads to mold and mildew around the frame.

3. Cracks and Damage

Cracks, whether small or large, mean it's time for a replacement. They can come from hail, falling branches or thermal stress. Beyond looking bad, cracks let heat escape in winter and cool air leak out in summer, and they can let water in.

4. Drafts

If you feel cold air around your skylight, the seals or insulation around the frame have likely failed. That makes your heating and cooling work harder and can lead to condensation problems too.

5. Discoloration and UV Damage

Older plastic and acrylic domes especially can turn yellow, cloudy or brittle after years in the sun. That cuts the light coming in and makes the dome more likely to crack. If your skylight looks hazy or discolored, it's time to think about replacing it.

6. Outdated Design

If your skylight is more than 15 to 20 years old, newer models likely perform much better. Today's units generally offer better insulated glass, low-E coatings that cut heat gain and UV, and improved flashing kits designed to shed water. Venting models can also let out summer heat and bathroom humidity.

Replacing Your Roof? Replace the Skylight Too

If you're planning a roof replacement, it's the ideal time to replace an older skylight. The roofing around it is already off, so the new unit can be flashed properly into the new roof and underlayment. That usually costs less than replacing it separately later, and it avoids cutting into brand-new shingles.

Upgrade Your Skylight With Allabaugh Construction

Catching the signs early helps you avoid bigger water damage. We handle skylight installation, replacement and leak repair for homeowners across Mercer County, NJ and Lackawanna County, PA, whether on its own or as part of a new roof. Read our pros and cons of skylights if you're deciding whether to keep one.

Call our NJ office at (609) 477-0487 or our PA office at (814) 330-4897, or request a free estimate.