How Long Do Skylights Last in Skagit County?

Updated August 2026 · Alpine Exteriors · WA contractor license ALPINI751OW

The Short Answer

Most residential skylights installed in Skagit, Island and Whatcom County homes last somewhere between 10 and 20 years before they need to be replaced, not repaired. The glass or acrylic itself often outlasts that window, but the seals, flashing and gaskets that keep water out rarely do, and in this climate those components are usually what ends a skylight's useful life first.

The Detail Behind It

A skylight isn't one part, it's a small system: a glazing unit (glass or acrylic), a frame, a curb or deck mount, flashing that ties into the surrounding roofing, and seals or gaskets at every joint. Each piece ages differently, and that's why "how long do skylights last" doesn't have a single clean number.

Acrylic dome skylights, common on older homes and additions from the 1980s and 90s around Mount Vernon and Burlington, tend to show their age first. UV exposure and years of rain cause the plastic to yellow, craze (that fine web of surface cracks), and lose clarity, typically somewhere in the 10 to 15 year range. They rarely leak catastrophically, they just get cloudy and brittle until a homeowner decides the view isn't worth looking at anymore.

Glass skylights, especially insulated (double- or triple-pane) units installed to meet current energy code, generally hold up better optically and can run 20 years or more before the glass itself is the problem. What fails first on these is almost always the seal between the panes. Once that seal breaks, you get fogging or condensation trapped between the layers, and no amount of cleaning fixes it, because the moisture is inside the sealed unit, not on the surface.

Flashing is the other half of the equation, and it's arguably more important than the glazing. Skylight flashing is a layered system, step flashing along the sides, a head flashing above, and a saddle or cricket behind the unit to divert water around it rather than through it. Flashing is typically rated to last as long as the roofing it's installed with, but it's also the single most common source of skylight leaks, usually not because the flashing failed on its own, but because it was installed against aging shingles, or the sealant at the corners dried out and cracked years before the metal did. A skylight can be replaced on a roof that's only 8 years into a 25-year shingle warranty and still leak within a couple of years if the flashing detail isn't redone correctly.

What Makes This Region Different

Skagit, Island and Whatcom counties put a specific set of stresses on a roof penetration like a skylight, and they're not the stresses skylight manufacturers design around for a national average.

• Volume of winter rain. This area doesn't get the dramatic downpours some regions do, but it gets sustained, weeks-long wet seasons where the roof and flashing are rarely fully dry. That kind of prolonged moisture exposure is hard on sealants and accelerates any small flashing gap into an active leak, especially around La Conner, Burlington and the lower Skagit flats where the terrain is flat and drainage is slower.
• Moss on shaded roofs. Homes tucked under fir and cedar canopy, common around Sedro-Woolley and the wooded lots outside Mount Vernon, grow moss on north-facing roof planes faster than open, sunny roofs do. Moss holds water against the roofing material and against skylight flashing longer than bare shingles would, and moss roots work into small gaps at flashing edges. A skylight surrounded by moss is sitting in a wetter microclimate than the rest of the roof.
• Wind off the flats and the Strait. The open Skagit flats funnel wind, and homes on Camano Island, in Anacortes, and along the water in Whatcom County take steady exposure off the Strait of Juan de Fuca and Rosario Strait. Wind doesn't usually rip a skylight off, but it drives rain sideways under flashing edges that would stay dry in calmer conditions, and repeated wind-driven rain is a slow way to find every weak point in an installation.
• Salt air on the islands. Camano Island and the Anacortes/Fidalgo Island waterfront deal with salt-laden air that corrodes exposed metal fasteners and flashing faster than inland Burlington or Sedro-Woolley. Galvanized flashing and standard fasteners can show rust and pitting well before their inland equivalents, which shortens the practical life of the flashing system even if the skylight unit itself is fine.
• Occasional ice and snow in the foothills. Higher elevations toward the Cascade foothills near Sedro-Woolley and Concrete see periodic snow load and freeze-thaw cycles that the valley floor rarely gets. Ice damming near a skylight curb, where snow melts from roof heat loss and refreezes at the eave or around the curb, can force water backward under flashing that was never designed to handle standing ice.
• Washington State Energy Code. Current code sets minimum U-factor and solar heat gain requirements for glazing, skylights included, which is one reason older single-pane or poorly insulated units get flagged during remodels and additions. It also means a straight swap of an old skylight for a similarly cheap unit may not meet code on a permitted project, which is worth knowing before assuming a like-for-like replacement is the simple option.

What the Homeowner Should Actually Do

The honest answer is that most skylight problems in this region show up as slow, small signs long before there's a dramatic leak, and catching them early is cheaper than waiting.

• Look for a stain ring, not a puddle. A faint brown or yellow halo on the drywall or trim around a skylight is usually the first visible sign of a flashing or seal issue. By the time water is actively dripping, the leak has likely been active for a while.
• Check for fogging between panes. If an insulated glass skylight looks permanently hazy or has condensation trapped between the layers, especially after a cold snap, the seal has failed. That's a glazing unit replacement, not a cleaning fix.
• Keep moss and debris off and around the unit. On shaded roofs, especially around Sedro-Woolley and wooded lots elsewhere in Skagit County, clearing moss and needle buildup away from the skylight curb at least once a year keeps water from sitting against the flashing.
• Know the roof's age relative to the skylight's age. If the roofing is due for replacement in the next few years, it's usually smarter to replace an aging skylight at the same time so the flashing is installed fresh into new roofing, rather than paying for flashing work twice.
• Get flashing inspected, not just the skylight. A skylight that looks fine from inside the house can still have degrading flashing on the roof. If a roof is more than 10 years old, or if a home was bought without full history on the roof work, it's worth having someone look at the flashing directly rather than assuming the absence of a visible leak means everything's sound.
• Budget realistically. Replacing a single residential skylight, unit plus proper flashing and labor, typically falls somewhere in the low thousands per opening depending on size, glazing type and roof access, with acrylic dome replacements usually cheaper than insulated glass units. Get a written scope that specifies the flashing method, not just the skylight brand, since flashing quality is what actually determines whether the job holds up through a Skagit County winter.

Alpine Exteriors, working under Washington contractor license ALPINI751OW, evaluates skylights as part of the surrounding roof system rather than as a standalone product swap, since the flashing detail and the roofing it ties into matter more to longevity here than the skylight brand does.

FAQ: Skylight Lifespan in Skagit County

Can a skylight be repaired instead of replaced?

Sometimes. A failed seal at the flashing edge or worn sealant around the frame can often be repaired without replacing the whole unit, especially if the glazing itself is still clear and intact. But once the insulated glass seal between the panes has failed, causing permanent fogging, or the acrylic dome has crazed and yellowed, repair won't restore clarity, and replacement is the more honest recommendation.

Do skylights cause more leaks than the rest of the roof?

Any roof penetration, whether it's a skylight, chimney, or vent pipe, is a higher-risk spot for leaks than an unbroken field of shingles simply because it interrupts the roofing material. Skylights aren't inherently leak-prone if the flashing was installed correctly against sound roofing, but they do concentrate risk at that one location, which is why flashing quality matters more than it might seem to at first glance.

Should a skylight be replaced at the same time as the roof?

In most cases, yes, if the skylight is more than about 10 to 15 years old. Reflashing a skylight into brand-new roofing is more reliable and often not much more expensive than reflashing it into roofing that will need replacement again in a few years, at which point the flashing gets disturbed a second time anyway.

Does skylight placement affect how long it lasts?

Yes. Skylights on shaded, north-facing roof planes tend to stay damp longer and collect more moss, which shortens flashing life, while skylights with more sun exposure dry out faster but take more UV exposure, which shortens the life of acrylic domes specifically. Skylights near the coast on Camano Island or around Anacortes also face faster corrosion on exposed metal fasteners and flashing due to salt air.

Talk to Alpine Exteriors About Your Skylight

If a skylight in your Mount Vernon, Anacortes, Burlington, Sedro-Woolley, La Conner, Stanwood, Camano Island or Bellingham home is showing staining, fogging, or you're just not sure how much life is left in it, Alpine Exteriors can take a direct look at both the skylight and the flashing around it and give you a straightforward assessment of whether it needs repair, reflashing, or full replacement. Contact Alpine Exteriors to schedule an inspection.