A skylight done right transforms a dark hallway, bathroom, or finished attic; done wrong, it's the most notorious leak source on a roof. The difference is almost entirely in the flashing, which is why skylights should be installed by roofers, not cut in as a side job. Roofing Renew installs, replaces, and repairs skylights across Bergenfield, Bridgewater, and Bedminster, NJ.
We handle three distinct jobs: new skylight openings, replacement of aging or fogged units (ideally timed with a re-roof), and diagnosing the leaky skylight someone else installed.
Reviewed by the Roofing Renew team · Published · Last updated
Skylight Problems We Fix
Existing skylights fail in recognizable ways, and not every 'leak' is actually a leak:
Water stains at the skylight corners
The classic flashing failure: water follows the frame and drips at the lower corners. Fixable with a flashing rebuild if the unit itself is sound.
Fogging between glass panes
Condensation inside the glass means the insulated seal has failed. The glass unit or whole skylight needs replacement, no sealant fixes it.
Condensation dripping in winter
Often mistaken for a leak: warm interior air condensing on cold glass, a sign of an older single-efficiency unit or humidity/ventilation issues rather than a roof breach.
Cracked or yellowed domes
Older acrylic bubble skylights get brittle and hazy with UV; modern glass units outperform them in every way.
Leaks after a re-roof that skipped the skylights
Re-using 20-year-old flashing on a new roof is a common shortcut that comes back as leaks. Skylights should be re-flashed, or replaced, whenever the roof is done.
Drafts and heat loss
Failed seals and aged frames leak air year-round; replacement units with low-E glass noticeably improve comfort in the room below.
How We Install a Skylight That Doesn't Leak
The sequence for a new deck-mounted skylight, the most common residential install:
Placement planning
We locate the unit between rafters for light, slope, and interior effect, checking attic obstructions (wiring, ducts, framing) before any cutting.
Unit selection
Fixed, manual-vented, or solar-powered venting; glass specs for energy efficiency and hail resistance; shades if wanted. We quote specific models, not allowances.
Opening and framing
The deck is cut, headers framed per code, and the curb or deck-mount prepared square and true, the geometry the flashing kit depends on.
Underlayment and ice-and-water sealing
Self-adhering membrane wraps the opening before the unit sets, the secondary water barrier if anything ever gets past the flashing.
Manufacturer flashing kit, installed to spec
Step flashing woven into each shingle course up the sides, head flashing above, sill below, the engineered kit, installed in the engineered order. This is the step DIY and handyman installs get wrong.
Interior finish and verification
The light shaft is insulated and closed up, the unit tested, and the work photographed for your records.
What Affects Skylight Project Pricing
Skylight quotes vary mainly on these points:
New opening versus replacement
Replacing a same-size unit in an existing opening is the simpler job; cutting a new opening adds framing, drywall, and finish work.
Unit type and features
Fixed units cost least; solar-venting models with rain sensors and factory shades sit at the top of the range.
Light shaft depth and finish
A skylight through a cathedral ceiling is minimal interior work; one through an attic needs a built, insulated, drywalled shaft.
Roof type and pitch
Flashing into asphalt shingles is standard; metal and flat membranes require different curb and flashing approaches.
Timing with other roof work
Replacing skylights during a re-roof saves meaningful labor versus a standalone visit, the shingle courses are already open.
Replace Your Skylights When You Replace Your Roof
A skylight's practical lifespan is roughly 20–30 years, the same window as the roof around it. Re-roofing around an old unit means either reusing aged flashing against new shingles or paying twice for the same flashing work a few years apart when the unit fails. If you're planning a roof replacement and your skylights are past mid-life, replacing them in the same project is almost always the economical call, and we'll quote it both ways so you can see the difference. Material choice interacts too, see our comparison of shingles vs. metal roofing if you're weighing systems.
Is It the Skylight Leaking, or the Roof Around It?
Water appearing at a skylight has four possible sources: the unit's seals, the flashing, the roof field above it, or interior condensation. Each has a different fix, and guessing wrong wastes money, resealing a skylight does nothing if the actual failure is a cracked shingle three feet uphill. We diagnose before quoting, the same way we approach any roof repair, and we'll tell you plainly if the honest fix is cheaper than you feared.
Skylight Installation FAQs
Do skylights always leak eventually?
No, that reputation comes from bad installs. A quality unit with the manufacturer's flashing kit, installed to spec with ice-and-water membrane beneath, should stay dry for the unit's lifespan. The leaks we're called to fix almost always trace to shortcut flashing, not the skylight itself.
Vented or fixed, which should I choose?
Fixed units cost less and never leak air; venting units earn their premium in bathrooms and kitchens where moisture escape matters. Solar-vented models with rain sensors close themselves when weather turns, convenient, and they avoid wiring.
Can you replace my skylight without replacing the roof?
Yes. We open the shingle courses around the unit, set and re-flash the new skylight, and weave the roofing back in. It's routine work, though if the roof itself is near end of life, we'll show you the combined numbers before you spend twice.
My skylight drips only in January, is that a leak?
Probably condensation: interior humidity hitting cold glass. It's the most common skylight misdiagnosis. The fixes range from a bathroom fan timer to a modern low-E replacement unit. A quick inspection settles which problem you actually have.
Do you install skylights in Bridgewater and Bedminster?
Yes, all three towns we serve. Finished attics and great rooms in Bridgewater and Bedminster homes are frequent skylight projects for us, as are the expanded capes of Bergenfield where upstairs rooms often have exactly one small window.