Do Skylights Cause Roof Leaks?

You’re standing in the living room on a rainy Tacoma afternoon when you hear that faint drip… drip… drip. You look up and see a tiny dark spot forming near the skylight. It’s one of those moments that makes every homeowner nervous — is the skylight leaking, or is it something else?

At Robb’s Roofing, we’ve seen this plenty of times. Skylights don’t automatically mean leaks, but they are one of the most common weak spots on a roof — especially as they age or if they weren’t installed right in the first place.

Why Skylights Start to Leak

Skylights sit right where warm indoor air and cold outdoor air meet, so they naturally collect moisture. Over the years, the seals and flashing around them can break down. Once that happens, water doesn’t need much encouragement to find its way in.

Here’s what usually causes the trouble:

• Old flashing that’s cracked, rusted, or pulled away from the roof.
• Improper installation — nails driven in the wrong spots or sealant skipped entirely.
• Cracked glazing or seals that let water sneak between the glass and frame.
• Condensation inside the skylight that looks like a leak but isn’t — it’s trapped moisture.

Quick Guide

Quick answer: Old or poorly flashed skylights often leak.

Try this: Reseal the flashing and check the glass for cracks.

Stop signs: Dripping, fogging between panes, or dark stains around the frame.

Typical cost: Resealing runs $300–$700; full replacement costs $1,500–$3,000 depending on size and type.

Why Tacoma Weather Makes It Worse

The mix of constant rain, wind, and humidity we get in the Puget Sound area is rough on skylights. The flashing expands and contracts every season, and that movement breaks the bond over time. Add in moss growth and debris clogging the roof around it, and water eventually finds the path of least resistance — usually straight into your drywall.

How to Tell It’s Time for a Repair

If you notice water spots forming around the skylight, don’t assume it’s just condensation. Look for:

• Soft drywall or peeling paint around the opening.
• Drips or dark edges on the ceiling after heavy rain.
• Fog or water between the panes — that means the seal has failed.

Once these signs show up, a small reseal can prevent a full-on replacement later.

How Robb’s Roofing Fixes It

When we inspect a skylight, we don’t just look at the glass. We check the flashing, roof slope, nearby shingles, and attic space underneath. If it’s a simple seal issue, we clean, reseal, and reinforce it with new flashing. If the skylight itself is too far gone, we’ll recommend a replacement built to handle Tacoma’s wet climate.

Skylights do not have to leak, but they do need attention. A little maintenance now keeps water out and daylight flowing in for years.

Call Robb’s Roofing at (253) 820-2163 for a skylight inspection in Tacoma. We’ll check the seals, test the flashing, and make sure your skylight stays bright — not dripping.