Skylight Replacement vs. Re-Glazing: Dome, Flat Glass, and Curb Decisions

A skylight is a roof first and a window second. That one fact decides almost everything about fixing one. When the glass fogs, cracks, or turns yellow, most homeowners assume the whole skylight has to come out — and sometimes it does. But often the frame, the flashing, and the curb underneath are still sound, and only the glazing itself has failed. That job is a re-glaze: a new glass unit set into the existing skylight. The trick is knowing which situation you are in before anyone orders anything, because re-glazing a skylight whose curb is rotting is money thrown at a leak, and replacing a skylight whose only problem is a fogged unit is money thrown at nothing.

What re-glazing actually means

Re-glazing keeps the skylight frame, the curb, and the roof flashing exactly where they are, and replaces only the light itself — the pane or insulated unit that sits in the frame. It is the right fix when the failure lives in the glass:

• Fog between the panes. The sealed insulated unit has failed, the same as a foggy window. A new unit restores the view and the insulation without touching the roof.
• A cracked or crazed lite. Impact damage, heat stress, or an acrylic dome that has gone brittle and spider-cracked with age.
• Yellowed, hazed plastic. Old acrylic and polycarbonate domes cloud over after years of Los Angeles sun. The frame below them is usually fine.
• An upgrade in performance. Swapping a single-pane or clear unit for a laminated, low-E insulated unit cuts heat and UV and adds safety glass overhead — where it matters most.

Overhead glass has one non-negotiable: it must be safety glazing, and laminated glass is the standard choice because if it ever breaks, the interlayer holds the pieces in place instead of dropping them into the room. Any re-glaze we quote for a skylight starts there. Our skylight service covers both paths — re-glazing sound frames and full replacement when the frame or curb is the problem.

When the whole skylight has to go

Replacement is the right call when the failure is not in the glass at all. A frame that is corroded, warped, or cracked at the corners will leak around brand-new glass. Gaskets and seals that have hardened and shrunk past resealing do the same. A skylight that has been patched with surface sealant three times is telling you the system is done, not the sealant. And size matters: builders-grade skylights from a tract build twenty-plus years ago were often thin, single-layer units in frames that were never meant to be serviced — there is nothing worth saving to re-glaze into.

Leaks deserve special honesty here. If water is coming in, do not assume new glass fixes it. A leak at the flashing or the curb survives a re-glaze untouched, and you will have paid for glass and still own the stain on the ceiling. That is why a leaking skylight gets diagnosed first — glass, seal, or flashing — and only then quoted.

The curb decides more than the glass

Most residential skylights are either deck-mounted, sitting low directly on the roof deck, or curb-mounted, sitting on a raised wood or metal curb — a short boxed frame built up from the roof. The curb is the skylight's foundation, and its condition decides the job:

• Sound curb, sound flashing: re-glazing or a like-for-like curb-mounted replacement is straightforward, and the roof itself barely gets touched.
• Soft, rotted, or water-stained curb: the curb gets rebuilt and re-flashed as part of the job. Setting a new skylight on a bad curb just schedules the next leak.
• Curb height: a curb that is too low for the roof type lets standing water reach the frame in a hard rain. Raising it during replacement is cheap insurance you only get one chance to add.

On a curb-mounted unit, full replacement can actually be the less invasive job — the new skylight drops over the existing curb like a lid. On a deck-mounted unit, replacement means opening the roofing around it and re-flashing, which is real roof work and should be planned, not improvised.

Dome or flat glass?

The dome is the older form: a molded acrylic or polycarbonate bubble. Domes shed water well, they are light, and their shape adds a little headroom and diffused light. Their weakness is the material — plastic hazes, yellows, and goes brittle in the sun, and it insulates poorly. Flat glass skylights use a real insulated unit, usually tempered over laminated, in a metal frame. They look cleaner on a modern house, they insulate and cut heat far better with low-E coatings, they stay clear, and the glass does not degrade the way plastic does. If your dome has clouded over for the second time, that is the pattern telling you to switch forms, not to buy a third dome. If the roof is low-slope and water pools, the dome's shedding shape still earns its place — form follows the roof, not the catalog.

The short answer

Re-glaze when the glass failed and the frame, seals, and curb are sound. Replace when the frame is done, the seals are past saving, the curb is soft, or the unit was never serviceable to begin with. Check the curb before you price the glass, and never let a re-glaze quote talk you out of a leak diagnosis. If your skylight is fogged, cracked, yellowed, or dripping, send us photos from inside and — if you can do it safely from the ground or a window — from outside, and tell us whether it has ever leaked. We will tell you straight which job you actually have, re-glaze or replacement, and give you an exact quote for that one.