Skylights are a roofing job
Whether a skylight stays dry depends on the framing around the opening and how the flashing integrates with the roofing. That is roofing work. We install fixed, venting and tubular skylights, and we replace aging units with new flashing every time.
- Skylight installation: new skylights and sun tunnels for kitchens, baths, stairwells and attic rooms
- Skylight replacement: leaking, fogged, cracked or outdated units replaced with new flashing
- Framed opening: headers carry the roof load around the cut rafters.
- Ice-and-water collar: self-adhered membrane sealed to the deck and up the curb, under all metal flashing.
- Head flashing on the uphill side tucks under the shingles above.
- Apron (sill) flashing on the downhill side lies over the shingles below, so water always flows onto the next layer down.
- Insulated, low-E glazing limits heat gain and condensation.
- Light shaft carries daylight to the room below.
Step flashing on the sides of the skylight, woven course by course with the shingles, is not visible in this section.
Skylights under a shady canopy and a humid summer
Skylights earn their keep in this area for a specific reason: the mature canopy that shades Bethesda and Chevy Chase streets also keeps the interiors of their houses dark. Center-hall colonials and foursquares have deep plans where stairs, hallways and renovated bathrooms sit far from any window, north-facing rooms get no direct sun at all, and the long low rooflines of mid-century homes in North Bethesda often cover rooms with very few openings. A skylight or a tubular sun tunnel is frequently the only way to bring real daylight into the middle of those houses without changing an exterior elevation that an HOA or a historic district would want to review.
Our climate then decides the specification. High summer sun and humidity mean glazing with a low solar-heat-gain coating, or a factory blind, is what separates a bright room from an unusable one, especially on south and west-facing slopes. Winter reverses the problem: insulated warm-edge glass and a shaft that is genuinely insulated and air-sealed through the attic are what keep humid indoor air from condensing on the cold glass perimeter and dripping. Condensation mistaken for a leak is one of the most common skylight complaints we see, and the cure is usually in the attic rather than on the roof. Curb height is the other local variable, because so many skylights here sit on porch roofs and rear additions where a shallow pitch demands a taller curb than a steep slope does.
Choosing between the two services is usually about the condition of the existing unit. Hazed or crazed acrylic domes, fogged first-generation glass and rotted site-built wooden curbs call for skylight replacement with a factory flashing kit matched to the roof pitch. Adding daylight where there is none now is skylight installation. Either way the flashing weaves into the surrounding roof, so the economical moment for both is during a roof replacement, and on low-slope porch and addition roofs the curb and membrane work is coordinated with flat roof repair. If the glass is sound but you see staining at the corners of the shaft, the problem is the flashing or the shaft, which is roof repair.
Frequently asked questions
Should I replace skylights when I replace my roof?
If your skylights are older or have leaked, yes. Replacing them with the roof means the new flashing is integrated with all-new roofing, and you avoid cutting into a new roof later.