Skylight Installation and Replacement in Londonderry, NH
A lot of Londonderry’s neighborhoods went up in the same building push, from the Mammoth Road corridor out toward the Windham and Derry lines, and that means a lot of original skylights are sitting at the same age right now. Add in the cathedral ceilings and open great rooms that builders liked in that era, and you get more skylight square footage per house here than you’d find in an older Massachusetts town of the same size.
Skylight Installation and Replacement in Londonderry
Two different homeowners land on this page, and they’re making two different decisions. One has an old acrylic bubble skylight over a kitchen or bath that’s gone cloudy, sweats on cold mornings, and probably leaked once or twice already. That’s a replacement, and if it happens while the roof is already open for a reroof, it’s the cheapest good decision you’ll make on the whole project. The other homeowner has a dark hallway, a north-facing bedroom, or a stairwell that never sees daylight, and wants to cut something new into a roof that’s never had an opening. That’s a bigger job with a bigger price tag, because you’re not just swapping a unit, you’re building a new opening from the rafters up.
We do both. We don’t push one into the other. If your existing unit just needs a straightforward swap, we tell you that. If a new cut-in makes sense for the room you’re trying to fix, we walk you through what that actually involves before you commit to it. Couture’s works on both sides of the Massachusetts and New Hampshire line, so a Londonderry address isn’t a special trip for us, it’s a normal Tuesday.
Deck-mounted
units fasten straight to the roof deck and use a matched step-flashing kit. This is what goes on most pitched roofs now. It sits low, looks clean and handles snow well.
Curb-mounted
units sit on a raised wood frame built on the roof. They are the right call on low-slope sections, generally below about 3 in 12, and a lot of older installs already have them.
Fixed
units let in light and nothing else. Fine over a high cathedral ceiling you will never reach.
Manual or electric venting
units open to let heat and steam out. They earn their keep in kitchens and bathrooms.
Solar-powered venting
units run off a small panel, need no wiring to the house, and close on their own when the rain sensor gets wet.
What Londonderry roofs and homes are working with
Londonderry’s housing stock skews newer than what we see on a lot of our Massachusetts jobs, with big post-1980 subdivisions that are now hitting first-replacement age all at once, similar to what’s happening in Derry, Windham, and Salem NH right along with it. That’s good news in one way: fewer additions and roof-line surprises, more consistent framing to work with. But it also means that when one skylight in a neighborhood starts failing, the others on the same street usually aren’t far behind, because they were all installed in the same handful of years by the same production builders.
Roof pitch and complexity vary more than people expect within town. The colonials and capes off Mammoth Road tend to have simpler roof planes, while the newer builds near the golf courses and further out toward Windham run more cathedral ceilings and steeper, more complex rooflines, which changes both the access and the flashing detail. Tree cover matters too. Londonderry has plenty of mature tree lines backing up to individual lots, and a skylight sitting under overhanging branches deals with more debris, more shade-driven condensation, and more granule wear on the surrounding shingles than one on an open, sun-exposed slope. North-facing sections are where we see the most ice dam risk in winter, which is exactly where a poorly flashed skylight curb turns into an interior stain by February.
How we assess it
Before we talk about a new unit, we look at what’s actually happening around the old one. That means pulling back the shingle course around the curb to check the step flashing and counter-flashing, not just eyeballing it from a ladder. We check the wood at the curb and the deck around the opening for soft spots or staining, because if there’s rot there, that gets addressed before anything new goes in, not covered over. We get into the attic or the cathedral ceiling cavity where we can and look at the underside of the opening, checking for daylight, moisture staining, or insulation that’s been packed too tight against the frame, which chokes off ventilation and causes condensation on the glass from the inside.
Ventilation is part of the same conversation. A skylight installed without enough ridge or soffit airflow around it runs colder in winter and hotter in summer than the rest of the roof, and that temperature swing is what drives condensation and, eventually, ice damming right at the curb. We tell you what we find and what it means before we talk about brands or units. An assessment happens first. The recommendation comes after, not before.
What the job involves
Replacement
We strip the shingles around the unit, pull the old skylight and flashing, repair the deck at the opening if it needs it, and set the new unit. Ice and water shield wraps up the sides and across the top, the step-flashing kit goes on, and we shingle back in. If the new unit matches the rough opening, the interior usually stays as it is. On a full roof replacement in Londonderry, all of this fits inside the reroof. The shingles are already off, the deck is exposed, and the new underlayment and flashing tie in as one system.
New cut-in
We lay out the opening from inside and out, cut the deck, and frame headers between the rafters. Ventilation gets rerouted so the bays above and below the opening still breathe. Then the unit, ice and water shield, flashing and shingles. Inside, a new opening means a light shaft through the attic, drywall and paint. That interior work is part of the conversation at the estimate, and we settle who handles what before anything is scheduled.
For a replacement, the work centers on the opening you already have. If the existing unit is curb-mounted, we can often match that footprint with a new curb-mounted or deck-mounted unit, whichever fits the existing framing best. Deck-mounted units sit lower and shed water more efficiently, which is why a lot of manufacturers have shifted that direction, but curb-mounted still makes sense on some retrofits where changing the profile would mean more carpentry than the job calls for.
For a new cut-in, we’re building the opening. That means framing a header into the rafters, cutting the deck, setting the curb, and integrating flashing with the surrounding shingle field so water sheds around the unit the way it’s supposed to, not into it. Ice and water shield goes down around the entire opening before the unit or the surrounding shingles go back on, which is non-negotiable on a New England roof. On the interior side, a new cut-in usually needs a light shaft framed and finished down to the ceiling below, plus drywall and paint. That finish work is part of the conversation we have with you up front, and we’ll tell you plainly what’s involved, but it’s not something we’re promising to hand you a turnkey answer on here.
On unit type, you’re choosing between fixed glass, manually venting units that open for airflow, and solar-powered venting units that open on a sensor and run off a small panel with no wiring needed. Fixed is the cheapest and simplest. Venting costs more but actually moves air out of a stuffy upstairs bathroom or kitchen. Solar-powered venting splits the difference, no electrician needed, and it’s become the more common upgrade choice on the replacements we do.
What it costs
A straightforward skylight swap, same size and same mounting style, done while a reroof is already underway, typically runs {PRICE_LOW} to {PRICE_HIGH}. That range moves based on unit size, whether you’re upgrading from fixed to venting or solar-powered venting, and how much flashing work the existing opening needs. A new cut-in costs more, because you’re paying for the framing, the deck cut, the flashing integration, and the interior light shaft work, in addition to the unit itself.
What moves the number most: curb-mounted versus deck-mounted, unit size, roof pitch and how much staging or access the crew needs to get up there safely, whether the decking around the opening turns out to be sound or needs replacement once we open it up, and how much interior finish work the job calls for. The single biggest cost factor, though, is timing. Replacing a skylight while the roof is already open for a reroof means the crew is already up there, the shingles are already off, and the flashing work gets folded into work that’s happening anyway. Doing that same replacement as a standalone job later means remobilizing a crew, opening a section of a good roof, and paying for that access all over again.
How long it takes
A same-size, same-mount replacement is usually a one-day job once the crew is on the roof. If it’s bundled into a full reroof, it adds to that timeline but doesn’t extend it much, since the roof’s already open. A new cut-in runs longer, generally two to three days once you count the framing, the deck cut, exterior flashing and shingle tie-in, and the interior light shaft rough-in. Weather and roof pitch can push that out a bit, and if the interior finish work is bundled in as a separate scope, that’s scheduled and priced on its own timeline.
Get an estimate
If you’ve got an old skylight that’s fogging up, sweating, or just looks tired, or you’ve got a dark room you’re finally ready to fix, walk us through it. We’ll come look at the roof, the flashing, and the space below before we talk numbers. Call Couture’s Construction at {PHONE} to set up a time, or reach out through the site and we’ll get back to you.
Can you replace a skylight without redoing the whole roof?
Yes. A standalone replacement is common, especially when the surrounding shingles still have life left. It costs more per unit than doing it during a reroof, but it doesn't require replacing the whole roof to get a working skylight back.
How do I know if my skylight needs replacing or just a repair?
If the glazing is cloudy, cracked, or the seal has failed, that's a replacement issue, not a flashing fix. If water is only showing up during heavy rain or ice dam season and the unit itself looks fine, that's more likely a flashing or waterproofing problem, which we handle as a separate service.
Do you handle the permitting for a new skylight in Londonderry?
Cutting a new opening into a roof deck typically requires a permit here, and we handle that as part of the job. Replacing an existing unit in the same opening usually doesn't trigger the same requirement, but we confirm that on a case-by-case basis before work starts.
What's the difference between curb-mounted and deck-mounted skylights?
Curb-mounted units sit on a raised wooden frame above the roof deck. Deck-mounted units sit flush and shed water more directly. Deck-mounted is more common in newer installations, but curb-mounted can still make sense on a retrofit if it matches your existing framing.
Will a solar-powered venting skylight cost more to run?
Ready to talk it through?
Reach out to Couture’s Construction and let us know if you’re dealing with a leaky or aging skylight, or dreaming up a new spot to bring in daylight. Share the room, the roof pitch if you know it, and any concerns you’ve noticed. We’ll schedule a visit to your Londonderry home, inspect the roofline and attic space, and walk through what makes sense before you commit to anything.