At Valley Roofing & Exteriors, we have spent more than two decades installing roofs and skylights across Central Virginia and the Shenandoah Valley. We know that not every homeowner is going to choose us for their project, and that is okay. You deserve a quality job and straight answers, no matter who you hire.
This article will walk you through when skylight replacement is necessary during a roof install, when it is optional, how roof type changes the calculation, and what it actually costs to get it wrong.
Why Is Replacing Skylights During a Roof Replacement Such a Common Concern?
Skylights sit at the most exposed point of your home. They take the worst of the sun, the heaviest rain, and the most punishing snow loads. Every skylight depends on glazing, seals, and flashing working in harmony, and every roof relies on those same skylights staying watertight. When the old roof comes off, the skylight is suddenly the oldest, most vulnerable component left.
Skylights are one of the most common sources of roof leaks, regardless of roof type.
In our experience, most failures come down to cheap skylights or poor installation, not skylights themselves being a bad idea.
What Makes Skylight Replacement More Important in the Shenandoah Valley?
Our valley does not give roofs an easy life. Snow piles up, ice dams form, summer humidity hangs heavy, and the freeze-thaw cycle works rubber seals like a kid working a piece of bubble gum. We also serve a region rich in historic and older homes, many of which still have original or first-generation skylights overhead. Think of:
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- Snow and ice: Seal expansion, contraction, and cracking
- Heavy seasonal rain: Higher leak potential at flashing joints
- Summer humidity: Condensation buildup between glazing layers
- Older housing stock: Outdated skylight materials and designs
What Happens If You Do Not Replace Skylights During a Roof Replacement?
Here is a real example from our crew. We were called to a property where a previous contractor had installed a new metal roof but left the existing deck-mount skylights in place. The contractor simply built flashing around the old units. Within a few years, the skylights failed, and the flashings failed right along with them. To do the job right, we had to remove three full panels of metal roofing just to access the skylights and rebuild the system properly.
In that case, the homeowner originally saved only a few thousand dollars by keeping the old skylights during the roof replacement. But when the skylights failed a few years later, the repair became far more expensive. Because the skylights were integrated into the finished metal roofing system, our crew had to remove and reinstall multiple metal panels just to access the old units.
What could have been a straightforward skylight replacement during the original roofing project turned into a much larger labor-intensive repair involving roofing tear-off, flashing reconstruction, and interior leak mitigation. In the end, the homeowner paid significantly more than they would have if the skylights had simply been replaced during the initial roof installation
Skipping replacement now almost always leads to higher costs later.
Should You Replace Skylights When Installing a New Roof? (The Short Answer)
In most cases, yes. The exception is a skylight installed within the last few years that is still in excellent condition. Otherwise, the math is simple: a skylight glazing system has a 25 to 35-year lifespan, so if your skylight will not last as long as your new roof, replacing it later will cost more and risk damage to the new roof.
If your skylight will not outlast your new roof, replace it now.
When Can You Keep Your Existing Skylights?
There are real situations where keeping the existing skylights makes sense:
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- The skylight is relatively new (within the last five to seven years)
- There is no fogging, leaking, or visible damage to the glazing
- The flashing was installed correctly and is still in good condition
- The expected lifespan of the skylight aligns with the expected lifespan of the new roof
Even then, you’re accepting some risk if the skylight fails before the roof.
When Should You Replace Skylights During a Roof Installation?
Replace the skylight when any of the following are true:
- The skylight is 15 to 20 years old or older
- You see fogging between the glass panes, cracks in the glazing, or active leaks
- The skylight has a history of repairs or sealant work
- It was poorly installed or uses an outdated design
How Does Roof Type Affect the Decision?
Shingle roofs are easier to work around, and deck-mount skylights are most common here.
A deck-mounted skylight is integrated directly into the shingles, which means replacing it later requires pulling shingles up and redoing the surrounding roofing.
Doing both jobs at once is much more cost-effective. Asphalt roof lifespans (15 to 30 years) also tend to line up well with skylight lifespans.
Metal roofs are a different beast. According to the Metal Roofing Alliance, metal roofs last 40 to 70 years or more, expand and contract with temperature, and require specialized flashing.
We strongly prefer curb-mounted skylights on metal roofs because the curb separates the skylight from the metal panels. If the skylight ever fails, we just unscrew it from the side and pop a new one in. The roof itself never gets touched.
| Mount Type | How It Works | Best Fit |
|---|---|---|
| Deck mount | Fastens directly to the roof deck, integrated with shingles, with a manufacturer’s flashing kit sized to the unit | Asphalt shingle roofs |
| Curb mount | Sits on a 2×4 or 2×6 wood curb that lifts the glass off the roof, screwed in from the side | Metal roofs and other long-life systems |
What Are the Best Skylights for a New Roof?
We install Velux skylights exclusively. While Velux is our preferred brand, there are other quality options. The key is proper installation and matching the skylight to the roof system.
Velux is the world’s largest skylight manufacturer and the only one consistently pushing the technology forward. They offer:
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- Solar-operated and electric venting models
- Rain sensors that automatically close an open skylight at the first drop
- Smart-home integration so you can open or close skylights from your phone, even from the other side of the world
- Integrated, remote-controlled blinds
- Flashing kits that are virtually foolproof when installed to specifications
Most homeowners assume skylights are problems. In our experience, the problem is not the skylight itself; the problem is the brand or the installation quality.
A quality Velux, installed well, simply does not leak.
How Long Is the Warranty on a New Skylight?
A Velux skylight carries a 10-year manufacturer’s warranty on the unit. As a Velux Certified Installer, Valley Roofing & Exteriors backs the installation with our own 10-year workmanship warranty. That is a full decade of coverage on both the product and the install, which is rare in roofing.
How Does Valley Roofing & Exteriors Approach Skylights?
Every roof estimate we provide includes a full skylight evaluation. We tell you what we see, recommend replacement only when the lifespan math says it is the smart move, and explain the trade-offs in plain language.
Our goal is not to add line items; our goal is to make sure your roof and your skylights age together gracefully.
Are You Ready to Line Up Your Roof and Skylights?
You now know the lifespan math, the difference between curb and deck mounts, why metal roofs change the equation, and why we trust Velux above all other manufacturers.
If your skylights are 15 years or older, then replacement is almost always the safer investment.
If you are installing a long-life roof, such as metal, then your skylights need to match that lifespan, ideally on a curb mount.
If you are unsure about the condition of your skylights, then a professional inspection is the right next step.
Resolution comes from doing both jobs together. Remember the risks of skipping it: leaks, duplicated labor, and warranty headaches.
The relevant next step is a real evaluation of your skylights before any roofing work begins. And whenever you are ready, Valley Roofing & Exteriors is here to walk you through it.
Take a look at our project gallery to see what quality roofing and skylight work looks like in the valley.
When you are ready to talk specifics, schedule a discovery call, and we will give you a clear, honest plan for your home.









