- Most common cause: flashing, not the skylight
- Winter drips: often condensation
- Lifespan: 20–30 years for quality units
- Free skylight inspections
If water is coming from around your skylight, the skylight itself is usually not the problem — failed or poorly installed flashing is the most common cause we find, followed by debris dams on the uphill side. Two clues narrow it down fast: drips that appear on cold mornings and vanish in dry weather are almost always condensation, not a leak, while water that shows up during or after heavy rain points to flashing or a failed seal. Fogging between the glass panes is a third case entirely — that is a failed insulated seal, and it can only be fixed by replacing the unit.
Skylights have a complicated reputation in the Pacific Northwest. Homeowners love the natural light — especially during our long, gray stretch from November through March — but plenty of people have also lived with a skylight that drips, fogs up, or stains the drywall around it. So when a skylight starts acting up, the question we hear most often is: should I repair it, replace it, or just get rid of it?
The honest answer is that it depends on the age of the unit, the condition of the flashing, and what the rest of your roof is doing. Here is how we walk homeowners in Portland, Vancouver, and the rest of Clark County through that decision — no pressure, just the same advice we would give a neighbor.
Is my skylight leaking, or is it the roof?
This is the question worth answering before anyone quotes you anything, because the three common causes call for three different fixes.
| What you’re seeing | Most likely cause | What fixes it |
|---|---|---|
| Drips on cold mornings, gone in dry weather; worst in bathrooms and kitchens | Condensation — warm indoor air hitting cold glass | Better ventilation, not roofing work |
| Water during or after heavy rain; stains spreading in the light shaft | Flashing failure — the metal channeling water around the unit | Reflashing, often without replacing the skylight |
| Water after rain on a roof with heavy needle or moss buildup | Debris dam holding water against the uphill flashing | Cleaning plus minor flashing work |
| Cloudy or fogged glass between the panes | Failed insulated seal | Replacement — the glass unit can’t be resealed in place |
| Cold draft underneath in winter | Older single-pane or acrylic unit | Replacement with a double-pane low-E unit |
The condensation case surprises a lot of homeowners. In our damp climate, water dripping from a skylight in winter is often not a roof leak at all — warm, humid indoor air rises, hits the cold glass, and condenses. If that is what is happening, the fix is attic and bathroom ventilation, and no amount of roofing work will solve it.
When a skylight repair makes sense
Not every leaking skylight needs to be torn out. In many cases the skylight itself is fine and the problem is around it. Good candidates for skylight repair include:
- Failed or poorly installed flashing — the metal that channels water around the skylight. This is the most common cause of skylight leaks we see.
- Cracked or deteriorated seals between the glass and the frame on a newer unit.
- Debris dams. Fir needles and moss build up on the uphill side of a skylight, hold water against the flashing, and force it under the shingles. Sometimes a thorough cleaning and minor flashing work solves the problem.
- Localized shingle damage around the curb from wind or a falling branch — often handled as part of a standard roof repair.
Because most of these are flashing problems rather than skylight problems, the cost tends to track with roof leak repairs generally rather than with the price of a new skylight. Our roof leak repair cost guide covers what that side of the work runs.
When replacement is the smarter move
Skylights do not last forever. Most quality units are built for roughly 20 to 30 years, and older ones — especially the acrylic bubble domes common on homes from the 1980s and 1990s — tend to fail in ways that are not worth patching. Replacement usually makes more sense when:
- The unit is 20+ years old and leaking. Repairing old flashing on an old skylight often just moves the leak to next winter.
- The glass is fogged between panes. That means the insulated seal has failed, and it cannot be fixed — only replaced.
- You feel a cold draft under it in winter. Modern double-pane, low-E skylights are dramatically better insulators than older single-pane or acrylic units.
- You are replacing the roof anyway — more on that below.
Thinking about adding one?
Adding a skylight is one of the most cost-effective ways to transform a dark kitchen, bathroom, or hallway — and in a climate where winter daylight is scarce, the difference is bigger than most people expect. A proper skylight installation involves framing the opening, building a light shaft through the attic if needed, and integrating the flashing kit with your existing roofing so it sheds water correctly. Placement matters too: a good installer will check rafter layout, attic obstructions, and sun exposure before cutting anything. Done right, a modern skylight with a factory flashing kit is not the leak risk the old ones were.
Why dry weather matters for skylight work
Skylight work means opening up a section of your roof. In the PNW, that is a job you want done in dry conditions, with time for sealants and underlayment to be installed properly before the fall rains and the first atmospheric rivers roll in. A dry roof deck means crews are not racing weather windows, and any hidden rot around the opening can be repaired without rushing. If you have been putting off a skylight decision, the dry stretch before the rain is the window to use — and if you have already missed it, the work is still routine, it just takes more scheduling care.
Replacing your roof? Do the skylights at the same time
If your roof is due for replacement, replace the skylights with it — even if they are not leaking yet. The reasoning is simple: a new roof in our area is a significant investment (typically $14,000 to $20,000 for a standard local replacement, as we cover in our roof replacement cost guide), and it should last decades. A 15-year-old skylight will not. If it fails in year five, someone has to cut into your brand-new roof to swap it, and that costs far more than it would have during the roof replacement itself, when the roofing around the opening is already off. Replacing skylights during a reroof adds a modest amount to the project and removes the most common future leak point from the equation.
Get an honest answer about your skylight
If a skylight is leaking, fogged, or you have been dreaming about adding one, the smart move is to have it looked at before the rain sets in. We will tell you plainly whether it needs a repair, a replacement, or nothing at all — that is how we have built our reputation in SW Washington and Portland.
Request a free estimate WA (360) 952-3998 · OR (503) 523-3449 · customercare@jobinroofing.comFrequently asked questions
Is my skylight leaking because of the roof or the skylight?
Usually the roof side — specifically the flashing around the skylight, which is the most common cause of skylight leaks we diagnose. Debris dams on the uphill side are the next most common. The skylight unit itself is more often the culprit when the glass is fogged between panes or the frame seals have cracked on a newer unit. Timing is the fastest clue: water during or after heavy rain points to flashing, while drips on cold mornings that disappear in dry weather are usually condensation rather than a leak at all.
What are the signs a skylight needs to be replaced?
Fogging or cloudiness between the glass panes means the insulated seal has failed and cannot be repaired. A noticeable cold draft underneath in winter usually means an older single-pane or acrylic unit. And a unit past about 20 years that has started leaking is generally worth replacing rather than reflashing, because repairing old flashing on an old skylight often just moves the problem to the next wet season.
How long do skylights last in the Pacific Northwest?
Quality modern units typically last 20 to 30 years. Our wet climate is harder on flashing and seals than drier regions, so regular roof maintenance — keeping debris and moss off the uphill side — makes a real difference in how long a skylight performs.
Do skylights always leak eventually?
No. That reputation comes from older units and shortcut installations. A modern skylight installed with its factory flashing kit, properly integrated with the underlayment, is very reliable. Most “skylight leaks” we diagnose are actually flashing failures, debris dams, or condensation.
Can you replace a skylight without replacing the roof?
Yes. A standalone replacement involves removing shingles around the opening, setting the new unit, and reflashing. It is routine work, and it goes most smoothly in dry conditions, which is worth factoring into when you schedule it.
Is a fogged skylight worth fixing?
Fogging between the glass panes means the insulated seal has failed. The glass unit cannot be resealed in place, so replacement is the practical fix — and new low-E glass will also cut heat loss and UV fading.
Will adding a skylight make my home colder in winter?
Modern double-pane, low-E units are efficient enough that the daylight gain is well worth it for most homes. Proper installation and a well-insulated light shaft matter more than the skylight itself.
