Skylight installer

What a skylight installer does, and when to call one

A skylight installer cuts a new opening in the roof for a first-time installation, or replaces an aging unit in an existing one, and flashes the skylight into the surrounding roofing so water sheds around it rather than finding its way into the ceiling below. The flashing, not the glass or the frame, is the part of this job that actually keeps the house dry, which is why it deserves more attention than the unit's appearance or brand name.

Call one when you see staining or a water mark on the ceiling near an existing skylight, when condensation collects between the panes or drips from the frame, when the seal looks cracked or the flashing appears lifted at an edge, or when you are considering adding a skylight as part of a larger renovation for natural light in a room that otherwise reads dark. A skylight near the end of its life often shows up first as a small, intermittent stain that only appears during certain storms, easy to dismiss until it is not, and by the time it drips steadily the ceiling finish around it usually needs repair too.

Not every leak near a skylight is the skylight's fault. Sometimes water is entering the roofing above or beside it and simply surfacing where the skylight happens to interrupt the ceiling, following the framing to the lowest point it can find. A good installer or roofer traces the water to its actual source before replacing anything, rather than assuming the skylight is guilty simply because it is where the stain appears.

A little condensation on the inside of the glass on a very cold morning is often just normal moisture in the house meeting a cold surface, the same thing that happens on any cold window elsewhere in the house. Condensation collecting between the panes, rather than on the inside surface facing the room, is the version that actually signals a failed seal and does not clear up on its own once the room warms up.

How to choose one, and where this goes wrong

Ask specifically how they plan to flash the unit into the existing roofing. This is, in a real sense, the entire job, since the glazing or the frame rarely fails first, the flashing around it does, usually at the corners or where it meets the shingle courses above. If you are re-roofing the house anyway, replacing an aging skylight at the same time is usually more efficient than treating the two as separate projects, since the flashing work overlaps and only needs doing once rather than twice by two different crews.

• Assuming any nearby leak means the skylight has failed. Trace it to the source first; replacing a skylight that was never the problem fixes nothing and leaves the actual leak to keep working at the roof.
• Treating a new opening the same as a swap. Cutting a brand new hole in the roof structure touches framing as well as roofing, and is often treated differently by local permit rules than replacing a unit in an opening that already exists.
• Skipping the roofer's opinion entirely. On an older roof, it is worth having whoever handles the surrounding roofing weigh in, not just a skylight specialist working in isolation on one small section of it.

Confirm who is responsible for the permit before work starts, since a new opening and a straight swap are not always treated the same way locally, and it is better to know that before the crew arrives than after.

For a room that cannot easily fit a full sized skylight, a smaller tubular unit is worth asking about. It brings daylight in through a narrow reflective shaft rather than a full opening, and involves a smaller cut in the roof and less framing work, which is worth knowing before assuming a full skylight is the only way to get natural light into a dim room.

What drives the price

A straight swap into an existing, properly sized opening costs meaningfully less than cutting a brand new one, which involves framing in addition to roofing work and usually a finished ceiling to match on the inside. Size, whether the unit opens for ventilation, and the glazing, a basic fixed pane versus a larger vented unit or specialty glass, all move price. Timing the work alongside other roofing saves on setup and flashing labor, since someone is already up there working on the surrounding surface and the material and equipment are already on site.

As with roofing generally, an old skylight ignored until it actively drips usually costs more in the end, once the ceiling finish and insulation beneath it need repair too, not just the unit itself. Catching a failing seal or lifted flashing early keeps this a contained job instead of a ceiling repair with a skylight replacement attached to it, which is a meaningfully bigger project than either piece would have been alone.

Even a well installed skylight benefits from periodic attention: reseating a seal, clearing debris from around the flashing, or a fresh bead of sealant at the edge are all far smaller jobs than a replacement and worth doing proactively rather than waiting for a stain to appear. As with the roofer covered earlier in this guide, catching a skylight's flashing wearing thin before it actually leaks is reliably the cheaper path, since water damage to the ceiling and surrounding finish adds an entirely separate repair on top of whatever the skylight itself needed. Access also plays a role: a skylight on a steep or high section of roof costs more to reach safely than one on a low, gentle slope, independent of the unit itself, and, as with several other trades in this guide, bundling a skylight replacement with other roof work due around the same time is almost always more efficient than paying for setup and access twice over.