Skylights don’t last forever. Even a well-installed unit will eventually reach the end of its life, seals fail, the glass fogs between the panes, and older single- or double-glazed units bleed heat in a way that modern glass simply doesn’t. This Toronto skylight replacement project shows how we remove a failing skylight and install a modern, energy-efficient replacement, usually within a single day.

Replacement is often misunderstood: homeowners assume it means tearing the roof apart. In reality, when the new unit is matched to the existing opening, a replacement is one of the cleanest, fastest upgrades we do, and the improvement in light and comfort is immediate and obvious.

The Challenge

The homeowners had a skylight roughly twenty years old that had begun to fog between the panes, a tell-tale sign the seal had failed and moisture had worked its way into the glass unit. A faint water stain had also started to spread on the ceiling below, and the room felt noticeably draftier in winter than the rest of the house.

Their biggest worry was disruption. They pictured a multi-day project with the roof left open, debris through the house, and a big bill for structural work. What they actually needed was reassurance that a like-for-like replacement could be done quickly and cleanly.

The Homeowner’s Goals

They wanted the old, failing unit gone and replaced with a modern skylight that wouldn’t fog, wouldn’t leak, and would cut the cold draft they felt every winter beneath it. Energy efficiency was high on the list, they were tired of paying to heat air that escaped straight through an aging skylight.

They also wanted the job done in a day, with the ceiling left clean and the interior finish untouched wherever possible, so their home wasn’t turned upside down for a straightforward upgrade.

Our Solution

We specified a VELUX deck-mounted replacement with Low-E3 glazing, sized precisely to the existing opening, and paired it with a brand-new factory flashing kit. Reusing an old opening but fitting fresh flashing is the sweet spot for replacements, it keeps the job to a single day while guaranteeing the weatherproofing is new, not decades old.

Matching the new unit to the existing curb meant we didn’t need to alter the roof structure or the interior shaft, so the replacement was fast, tidy, and far less invasive than the homeowners had feared.

Our Step-by-Step Approach

1. Assessment & Measurement

We started by inspecting the failing skylight inside and out, and measuring the existing opening precisely. Getting these measurements exactly right is what allows a same-day, drop-in replacement.

We also confirmed the roof deck and framing around the opening were still sound, so the new unit could seat cleanly without any surprise repairs mid-job.

2. Removing the Old Skylight

We carefully removed the old skylight and its worn, brittle flashing, protecting the surrounding shingles and the interior below from any debris. Old flashing is often where the failure started, so it all comes out, nothing gets reused.

With the opening cleared and cleaned, we prepared the deck to receive the new unit and its fresh weatherproofing layers.

3. New Flashing & Weatherproofing

We installed a brand-new factory flashing kit along with fresh ice-and-water membrane around the opening. This is the step that guarantees a replacement stays leak-free for decades, reusing old flashing is the number-one reason replacements fail prematurely.

Layered in the correct sequence for a Toronto shingle roof, the new flashing directs water over and away from the skylight, protecting against both rain and winter ice damming.

4. New Skylight Installation

The new energy-efficient VELUX unit was set into the opening, fastened, and sealed, then the surrounding shingles were re-integrated with the fresh flashing for a seamless, watertight finish.

As with every job, we water-tested the completed exterior before considering the work done, a replacement is only finished when we’ve proven it’s sealed.

5. Interior Refinishing

Because we matched the new unit to the existing opening, the interior shaft needed only light touch-ups rather than a full rebuild. We refinished any areas disturbed during removal so the ceiling looked clean and complete.

The result is a fresh, clear skylight in a crisp, stain-free ceiling, with no sign that a twenty-year-old unit was ever there.

The Result

The foggy, drafty old skylight is gone, replaced by a crisp, clear, energy-efficient unit. The room is visibly brighter, the winter draft has disappeared, and the ceiling stain has been resolved at its source rather than just painted over.

Best of all, the entire replacement was completed in a single day, with a watertight, fully warrantied result and a home left exactly as tidy as we found it.

Products & Materials

VELUX deck-mounted replacement skylight with Low-E3 glazing, a new VELUX factory flashing kit, and fresh ice-and-water shield membrane. The Low-E3 glass alone is a major upgrade over a twenty-year-old unit, far less heat loss, better UV filtering, and no more fogging. Every component carries VELUX’s 10-year warranty, backed by our workmanship guarantee.

Why Toronto Homeowners Trust TSI

We replace skylights across Toronto every week, so we know how to match a new unit to an existing opening and get the swap done in a single day without touching the roof structure. That experience is what keeps replacements fast, clean, and affordable.

Crucially, we always fit a fresh flashing kit rather than reusing old flashing, the shortcut that causes most replacement leaks. Doing it right the first time is why our replacements stay dry.

Frequently Asked Questions

Ready to Start Your Skylight Project?

Is your skylight fogging, staining the ceiling, or just getting old? We’ll assess it and give you a straight, honest answer on repair versus replacement, plus a clear, free quote. No pressure, no upselling.

Book Your Free Consultation