Skylights have a reputation problem in Texas. Ask around and half the people you talk to will tell you theirs leaked, and the other half will tell you theirs made the room unbearable in August.
Both problems are real and both are solvable. Here's the honest picture.
Why skylights leak
Almost never through the glass. Skylight leaks are flashing leaks, and they come from a small number of causes:
- Reused flashing on a new roof. The most common cause we find. A roof gets replaced and the crew shingles up to the existing skylight rather than pulling it and re-flashing properly. It buys a few years and then leaks.
- Sealant used instead of a flashing kit. Caulk is not a flashing system. Under Texas UV it becomes brittle and fails, typically faster than anything else on the roof.
- Age. Older units have gaskets and seals that degrade. Twenty-plus-year-old skylights are usually at end of life regardless of how the flashing was done.
- Debris damming above the unit. A skylight interrupts water flow down the slope. Leaves and catkins pile up on the uphill side, and standing water finds a way in.
- Condensation mistaken for a leak. Worth ruling out. Moisture appearing on cold mornings in a humid room may be condensation rather than intrusion.
The heat question
An old single-pane skylight in a Texas summer is essentially a solar collector pointed at your living room. That's the source of the bad reputation.
Modern units are a genuinely different product. Low-E coatings, argon fill, insulated glass and factory-integrated flashing systems perform nothing like a 1990s bubble skylight. If your experience of skylights is an old unit, it isn't a fair sample.
Options worth knowing about:
- Low-E glass as a baseline — non-negotiable in this climate
- Factory blinds, including solar-powered ones, for rooms that get too much afternoon load
- Tubular skylights, which deliver daylight to interior rooms and hallways with much less heat gain and a far simpler roof penetration
- North-facing placement where the layout allows, for even light without direct summer load
Replace them during a roof replacement
This is the practical advice that saves the most money and trouble.
If you're replacing your roof and your skylights are more than about fifteen years old, replace them at the same time. The labor to open and flash the penetration is already being done, the new unit gets an integrated factory flashing kit installed correctly into the new roof, and you don't end up replacing a skylight through a three-year-old roof later.
If the units are newer and sound, they should still be pulled and re-flashed with the new roof rather than shingled around.
Adding a skylight
Adding one is more involved than replacing one — it means cutting into the deck, potentially modifying framing, and building a light shaft through the attic. It's very doable and the effect on a dark room is dramatic, but it's a real project rather than an afternoon.
The best time to do it is during a roof replacement, for the same reason as above.
Our take
We're genuinely positive on skylights when they're installed correctly with modern units and proper flashing. We're not positive on inheriting a twenty-year-old unit and hoping. If yours is old and you're re-roofing, that's the moment to decide.
If yours is leaking now, we'll find whether it's the flashing, the seal, or something above it. Request an inspection or call (210) 245-4125.
