Local weather advisory
The National Weather Service has issued a coastal flood advisory covering Berkeley. Heavy rain and drainage loading can expose roof leaks, blocked drains, and ponding water. This is a weather exposure advisory; it does not establish damage to a specific roof.
Do not access a roof during hazardous weather. Protect people first, avoid water near electrical equipment, and request roofing help when conditions permit.
National Weather Service · Updated Oct 28, 2026, 7:20 AM UTC
Commercial roofing in Lafayette from our Berkeley crew: skylight replacements checked for curb fit, with the roof flashing rebuilt so the new unit does not leak.
Service Areas  | Berkeley, CA
Replacing an old commercial skylight sounds simple until the new unit shows up and does not match the curb. Sizes and curb designs change between manufacturers and over the years. The curb and the roof flashing around it have to work with the new unit, or the leak just moves. We repair commercial roofs in Lafayette from our base in Berkeley, CA, and we look at the actual opening before anyone orders a replacement.
Commercial buildings along Mt. Diablo Boulevard, from retail to public buildings like the Lafayette Library and Learning Center, each get their own skylight check. We measure the curb, look at how the old unit is attached and check how we can get materials onto the roof. The manager tells us what is in the room below before anything comes out. Our skylight and penetration flashing work is based on those measurements. Nobody should order a new skylight without knowing how the roof around it will be finished.
We measure the existing curb’s width, height and condition and compare them to the new unit’s specs. Those numbers often differ from the catalog description. We get what we need from the skylight supplier and whoever is installing the unit, then plan the flashing around the confirmed size. If the curb has to be rebuilt or resized, that is extra work beyond simple flashing, and we explain it before anything is ordered.
Our curb and rooftop support work keeps the roofing separate from changes to the skylight or the framed opening. If the opening needs to be resized, an engineer or the framing contractor may need to weigh in, and the estimate says who is responsible. We photograph the existing curb next to our measurements. That lets you compare a straight swap against a replacement that needs curb work, which can be a very different job even at the same opening.
A brand-new skylight can still leak if the membrane around the curb is worn out. We check the membrane at the base of the curb and the roof around it. Loose seams or layers of old patches change what the repair needs. The new flashing has to bond to clean, sound membrane, not to an old patch that is already failing. We find that solid edge before choosing how to flash the new unit.
Our commercial roof repair estimates around skylights include that prep work. When we pull back old flashing, we sometimes find rotted wood or wet insulation, and we show you photos before adding any work. Dry, solid layers can stay. The flashing still needs enough room around the curb to bond properly, which is why the roof repair often extends a foot or more beyond the skylight itself.
Water under a skylight can come from the glass seals, the frame, the curb flashing or the roof nearby. We check each of those separately and compare what we find with where and when the leak shows up inside. A stain on the ceiling does not by itself show where water got in. If the frame or glazing looks like the problem, we recommend the skylight installer take a look.
Our leak repair work around skylights covers the roof flashing and membrane. We note what we checked and what we could not get to. A good membrane does not rule out a leaking frame, so we tell you which part our repair fixes. Replacing the skylight should not be treated as proof that the roof around it is fine, or the other way around.
Taking out a skylight leaves an open hole over the room below. We find out what is in that room and plan how to protect it before anything is removed. The skylight installer handles the unit itself, and both crews need a safe route onto the roof. The day’s work has to be planned so the opening is closed up and flashed before we leave. If another trade is running late, we adjust when the old unit comes out.
Our reroofing over occupied buildings work includes protecting the room under the skylight. Debris and new parts need a path that keeps away from people using the building, and we check lift and staging space at each site. The manager gets a clear plan of when the opening will be made and when it will be closed. Doing one skylight at a time is often easier than opening several at once.
We photograph the curb and roof before the new skylight covers them, then take finished photos of the flashing and the unit. Wide shots tie each skylight to fixed landmarks on the roof. The record says which roof parts we rebuilt and what the skylight installer was responsible for. That gives the next inspector or the next leak call a clear starting point.
A building on Mt. Diablo Boulevard gets its own entrance and delivery plan, since the route onto the roof decides how the new skylight gets there. If you have properties in Orinda or Walnut Creek as well, we can schedule the visits together. Each building still gets its own curb measurements and room-protection plan, because skylight sizes and roof details vary from building to building.
If the curb is in good shape and only the flashing has failed, a focused repair usually makes sense. If the skylight is being replaced or the curb has rotted, the job gets bigger and involves more coordination. We explain why each added item is needed. A price that only covers new flashing may leave out curb or unit work, and we make that clear before anything starts.
On later maintenance visits, we keep skylight and roof issues separate. A failing glass seal needs the glazing contractor even if the roof flashing is fine. A loose flashing edge is ours to fix. We compare any new problem with the completion photos and where the leak shows inside, and go from there rather than assuming it is the same problem as last time.
Lafayette sees a wide range of temperatures, hot summers and cooler winter nights, and roofs here can age differently depending on which way they face. We look at both the sunny and shaded sections and compare the sealant, membrane and drains on each rather than assuming the whole roof wears evenly. For retail on Mount Diablo Boulevard, we set up so customers can still get in and note where a lift can go. If you are thinking about a coating, we check the existing roof and past repairs first.
Let us measure the curb and check the roof around it before you order. You get plain photos and a list of the roof work needed before the old unit comes out.
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