Skylight Leaking New Roof? Brooklyn’s Trusted Fix & Prevention

Did your skylight start leaking right after your “brand-new” roof went on? You’re not alone-and you’re probably furious. In Brooklyn, skylight leaks after roof replacement typically cost between $875 and $2,400 to diagnose and repair, depending on whether the problem is flashing failure, skylight damage, or installation errors. At Dennis Roofing, we get called in for these exact situations 4-5 times every month, usually when the homeowner is caught between a roofer pointing at an old skylight and a skylight company pointing at new flashing.

Here’s what most Brooklyn homeowners don’t realize: your new roof doesn’t automatically make your skylight watertight. The two systems have to work together, and that integration point-the flashing and curb around the skylight-is where 80% of post-installation leaks happen. Sometimes it’s the roofer’s fault. Sometimes the skylight was already compromised. Sometimes both crews did half a job. Let’s figure out what’s happening on your roof.

Why New Roofs Leak Around Skylights: The Real Causes

In a Bay Ridge townhouse we inspected last spring, the homeowner had a beautiful new architectural shingle roof installed in March. By the first heavy rain in April, water was running down the bedroom wall below the skylight. The roofing crew came back, caulked around the skylight frame, and left. Two weeks later, same leak. When we pulled back the shingles, we found the original 18-year-old flashing still in place-surface rust, bent corners, gaps at the head flashing. The roofer had shingled around it without replacing a single piece of metal.

That’s the most common scenario. Here are the actual failure points:

• Reused old flashing: Metal flashing degrades over 15-20 years. When roofers leave original flashing in place “because it looks fine,” they’re building a new roof around a failing component. We see this on probably 40% of the leak calls we get after someone else’s roof job.
• Incorrect flashing sequence: Skylight flashing must be layered in a specific order-base, step, head-and woven into the shingle layers. If a crew rushes or doesn’t understand how water flows, they’ll nail flashing in the wrong sequence or leave gaps where shingles meet metal.
• Missing kickout or cricket: On the high side of a skylight, water needs to be diverted around the frame. Without a properly built cricket (that small peaked structure behind the skylight), water pools and eventually finds a way through.
• Damaged skylight dome or frame: If the old skylight has cracks in the acrylic dome, degraded seals, or a warped curb, no amount of perfect flashing will stop water. The skylight itself is the leak source.
• Over-caulking instead of proper sealing: We see this constantly-roofers squirt caulk around a skylight frame instead of installing counter-flashing or using the manufacturer’s pan system. Caulk fails in 6-18 months under UV exposure and freeze-thaw cycles. It’s a temporary bandage that guarantees a callback.

In Brooklyn’s brownstone neighborhoods like Park Slope and Clinton Hill, we also deal with structural complications-roof decks that have settled or shifted over decades, creating slopes that direct water toward skylights instead of away from them. A new roof on an unlevel deck is still unlevel.

Who’s Responsible? Sorting Out the Warranty Mess

Here’s where it gets messy. You paid for a new roof. The roof is leaking. But the roofer is saying “that’s a skylight problem” and your skylight is 12 years old with no warranty left. So who fixes it?

The honest answer: it depends on what’s actually failing. A roofing warranty covers the roofing system-shingles, underlayment, and the flashing the roofer installed. If they reused your old flashing or installed new flashing incorrectly, that’s on them. If they damaged your skylight during the roof tear-off (we’ve seen crowbars punch through domes, or curb mounts cracked by careless debris removal), that’s also their liability.

But if your skylight was already at the end of its service life-seals degraded, frame weathered, dome crazed with micro-cracks-and the roofer documented that before starting, you’re looking at a skylight replacement, not a roofing repair.

The problem in Brooklyn is that most roofing contracts don’t spell this out. I’ve reviewed dozens of contracts where the skylight section just says “flash around existing” or “not responsible for skylight condition.” That’s a gap you can drive a truck through. At Dennis Roofing, we photograph every skylight before we touch the roof, note its condition in writing, and give homeowners a clear recommendation: replace now as part of the roof job, or accept that we’re flashing an aging unit that might fail on its own later.

In a Sunset Park job last year, we found a 22-year-old Velux skylight that was still structurally sound but had original flashing that was corroded at the bottom edge. We gave the homeowner two prices: $1,340 to replace all flashing and reuse the skylight, or $2,890 to replace the entire skylight with new Velux unit and flashing. They went with just the flashing. Three years later, no leaks. That skylight is probably good for another 5-8 years. But if it had shown any dome damage or seal failure, we would have refused to warranty flashing work alone-because we’d be back there in six months for a leak we couldn’t prevent.

Diagnosing Your Skylight Leak: What We Look For

When we get a call about a skylight leaking after a recent roof job, here’s our inspection sequence:

First, we look at the interior leak location. Water stains directly around the skylight frame usually mean flashing failure. Water running down the wall six inches away from the frame often means the leak is higher up-bad step flashing or a missing cricket. Water showing up only during wind-driven rain might indicate a gap in the counter-flashing where water is being forced upward.

On the roof, we check the flashing installation details. We pull back shingles at the head flashing to see if there’s a continuous metal pan underneath. We look at how step flashing is woven-each piece should be layered with shingles in a stair-step pattern, not just butted against the skylight curb. We check for a cricket or saddle on the high side. We inspect every nail placement-nails through the face of flashing create holes; they should be hidden under shingle tabs.

We examine the skylight itself. Dome condition, frame integrity, any visible cracks or impact damage. We look at the curb mount-is it level, is it sealed to the roof deck, are there gaps between the curb and the skylight frame? On older units, we check the weep holes (small drain ports at the bottom of the frame) to see if they’re clogged or if water is pooling inside the frame channel.

Then we test with water. A garden hose, low volume, starting below the suspected leak point and working upward. We’re looking for where water first enters. Sometimes we’ll run water for 15 minutes straight on one section of flashing to replicate the conditions of a heavy Brooklyn rainstorm. If it doesn’t leak with a hose, the problem might be ice damming or a specific wind direction that drives rain into a particular gap.

This diagnostic process takes 45-90 minutes and costs $175-$240 in Brooklyn if we’re not the original roofer. If Dennis Roofing did your roof and it’s within the warranty period, we come out at no charge. If another company did the work, we’ll still diagnose it-and we give you a written report with photos that you can take to the original contractor or use for your own records if you need to escalate.

What It Costs to Fix a Leaking Skylight After Roof Replacement

Repair costs depend entirely on what failed. Here’s the Brooklyn pricing breakdown we’ve seen over the past three years:

The majority of post-installation skylight leaks we fix fall into that first or second category-flashing work that should have been done correctly the first time. If your roof is less than a year old and the original roofer is still in business, you should absolutely push them to fix it under warranty before you pay anyone else. Get it in writing if they refuse or claim it’s “not covered,” because that documentation matters if you end up in small claims court or filing a complaint with the Better Business Bureau.

How to Prevent Skylight Leaks When Getting a New Roof

If you’re planning a roof replacement and you have existing skylights, here’s what you need to hammer out before signing the contract:

Get a written skylight assessment. Ask the roofer to inspect each skylight and document its condition-age, dome integrity, frame condition, curb structure. If they recommend replacement, get the reasons in writing. If they say it’s fine to reuse, get that in writing too, along with what warranty they’ll provide on flashing work around an old skylight.

Specify flashing replacement in the contract. Don’t accept vague language like “flash skylights.” The contract should say “remove and replace all skylight flashing with new [material type-usually aluminum or copper] step, base, and head flashing per manufacturer specifications.” If they’re reusing any components, you want to know which ones and why.

Confirm cricket installation. Any skylight wider than 30 inches needs a cricket or saddle on the high side to divert water. This should be in the scope of work. In Brooklyn, where we get nor’easters that dump 3-4 inches of rain in a few hours, a missing cricket will absolutely cause a leak.

Ask about deck inspection around skylights. When the old roof comes off, the crew should check the plywood or planking around each skylight for rot, soft spots, or water damage. If they find problems, you need a change order price before they start ripping up decking. We’ve seen contractors discover rotten decking and then hit homeowners with surprise bills 3x the original quote because “we didn’t know how bad it was.” Fair enough-but you should still get an itemized price for deck repair before they proceed.

Discuss skylight age and replacement timing. If your skylights are 15+ years old, have an honest conversation about whether to replace them now. A skylight costs $1,800-$2,400 installed during a roof job. If you wait and replace it three years later, you’re paying $2,200-$3,200 because we have to cut back the new roof, install the new skylight, and then re-flash and re-shingle around it. It’s almost always cheaper to do it during the roof replacement if the skylight is near end-of-life anyway.

Red Flags: When Your Roofer Isn’t Being Straight About Skylights

In Bensonhurst a couple years back, we got called to a house where the homeowner had paid for a full roof replacement three months earlier. The skylight was leaking, the roofer kept coming back to caulk it, and finally stopped returning calls. When we got up there, we found that the crew had never even removed the old flashing-they’d just laid new shingles over the existing metal and squeezed a thick bead of caulk where the shingles met the skylight frame. It was a $12,000 roof job, and they’d taken a $30 shortcut on every skylight.

Here are the warning signs that a roofer isn’t going to handle your skylights correctly:

• They won’t put the skylight plan in writing. If they verbally promise to “take care of the skylights” but the contract just says “roof replacement,” you have no recourse if there’s a problem. Everything should be itemized.
• They give you one price for the whole job without breaking out skylight work. Legitimate roofers separate costs-roofing square footage, skylight flashing (per unit), chimney flashing, etc. A single lump sum makes it impossible to know what you’re actually paying for.
• They refuse to replace flashing on old skylights. Some crews will say “we don’t touch the flashing because we don’t want to be responsible if the skylight itself leaks.” That’s a cop-out. A professional roofer flashes skylights correctly and documents the condition of the skylight so everyone knows what’s new and what’s reused.
• They pressure you to replace skylights without clear reasons. The flip side-some contractors push for skylight replacement on every job because they make more money. If your skylight is 8 years old, in good shape, and they’re insisting it “has to” be replaced, get a second opinion.
• They don’t carry photos or documentation from the job. After we complete a roof with skylights, we give the homeowner a photo set showing the new flashing installation, any deck repairs, and the final roof condition. If a roofer can’t or won’t provide that documentation, you have no proof of what was actually done.

When to Replace the Skylight vs. Just Fix the Flashing

This is the question we get asked most often when diagnosing a leak. The answer depends on three things: skylight age, physical condition, and your budget timeline.

Replace the skylight if:

• It’s 20+ years old, even if it’s not currently leaking
• The dome has visible cracks, crazing (that milky haze), or impact damage
• The frame is warped, the curb is rotted, or there are gaps between components
• The seals around the glass or dome are degraded (you’ll see daylight or feel drafts)
• You’re getting condensation between panes on a double-glazed unit
• The operating mechanism is broken on a venting skylight and parts aren’t available

Just fix the flashing if:

• The skylight is less than 12-15 years old and structurally sound
• The dome is clear, the frame is solid, and seals are intact
• The leak started immediately after the roof work (strong indication it’s installation-related)
• Water testing shows the leak is coming from the flashing layers, not the skylight itself

There’s a middle ground too. In a Crown Heights renovation last fall, we found a 16-year-old skylight with perfect dome and frame but original flashing that was failing at the bottom corners. We replaced all the flashing with new aluminum, added a small cricket that the original installer had skipped, and warranted the flashing work for ten years. We told the homeowner straight up: “This skylight has maybe 5-7 years left before the seals start to go. Our flashing will outlast the skylight. When you’re ready to replace the skylight, call us and we’ll integrate the new unit with this flashing system.” That’s a fair deal-they got a reliable fix for $1,380 instead of a $2,600 full skylight replacement, and they know what to expect down the road.

Working With Dennis Roofing on Skylight Leak Repairs

When you call us about a skylight leak after a roof replacement, here’s how we handle it:

We schedule an inspection within 3-5 business days (faster if it’s actively leaking and causing interior damage). Our inspector goes up on the roof, checks the flashing installation, examines the skylight, and runs water tests if needed. You get a written report the same day or next morning with photos, a clear diagnosis of what’s failing, and a repair estimate. If the original roofer is at fault and still in business, we’ll document everything you need to go back to them for a warranty claim.

If we’re doing the repair, we pull the necessary permits (required in Brooklyn for some skylight work), order materials, and usually complete the job within one week of estimate approval. For flashing repairs, we remove shingles around the skylight, pull out the old or incorrect flashing, inspect the deck, install new flashing in the correct sequence, and re-shingle. We test with water before we leave. You get a ten-year labor warranty on our flashing work and a detailed invoice showing exactly what was replaced.

For full skylight replacements, we coordinate with manufacturers (we install Velux, Sun-Tek, and FAKRO regularly) to get the right size and model for your roof. We handle the removal, any deck repairs, new curb installation if needed, flashing, and interior finishing. Timeline is usually 1-2 days depending on skylight size and how many we’re replacing.

We also handle the awkward situations-like when you’re mid-dispute with another roofer and need a third-party assessment for a small claims case or insurance claim. We charge our standard diagnostic fee ($185 for straightforward inspection, up to $290 if we need to do extensive water testing or pull back multiple shingle sections), and we give you a notarized report if you need it for legal purposes.

Final Thoughts: Don’t Let a Skylight Leak Ruin Your New Roof Investment

A new roof in Brooklyn is a $12,000-$28,000 investment depending on your home size and materials. If your skylight is leaking three weeks after installation, you’re rightfully frustrated. But here’s what I tell every homeowner in this situation: act fast, document everything, and don’t let a roofer kick the can down the road with temporary fixes.

Caulk is not a solution. “Let’s see if it leaks again” is not a plan. A leaking skylight will damage your ceiling, your insulation, and eventually your roof deck if it’s not fixed correctly. Water doesn’t take breaks-it just keeps finding the path of least resistance until something stops it.

If you’re in Brooklyn and dealing with a skylight leak after a recent roof job, call Dennis Roofing at (718) 555-0147. We’ll figure out what’s actually wrong, give you a fair price to fix it permanently, and make sure you understand exactly what failed and why. Whether it’s a $900 flashing repair or a $2,400 skylight replacement, you’ll get honest answers and work that’s done right the first time-which is what you should have gotten from your roofer to begin with.