Commercial Skylight and Penetration Flashing in Daly City, CA

A skylight curb begins at the opening, but the flashing scope reaches beyond the visible frame. We identify the curb height, membrane turn-up, counterflashing, sealant joints, and any adjacent roof transitions before deciding what to remove. A general contractor needs the scope boundary because glazing, framing, electrical work, and roofing may meet at the same opening. We photograph the condition from the roof and, where permitted, the interior, then label each view by roof area. City plans describe commercial settings at Serramonte and Westlake, with business corridors on Mission Street and Geneva Avenue. The City's regional profile also notes nearby employment destinations in San Francisco and San Mateo County, not a skylight condition. Those facts provide regional context, not evidence about a particular skylight. A commercial roof inspection can document surrounding conditions, and flashing failure repair addresses a failed roof transition.

The proposal should state whether it includes roofing membrane, curb metal, sealant, glazing, or interior finishes. A roofer can scope the waterproofing connection and identify where glazing or framing work belongs with another trade. If a skylight is being replaced, the rough opening and curb dimensions need confirmation before metal is fabricated. We identify the existing curb material, attachment, and access limit, then note whether surrounding insulation or deck may be affected by removal. Do not carry a broad allowance that makes the trade boundary unclear. The edge-metal and coping work can define adjacent metal where the same roof area has parapets or fascia. A PVC membrane or TPO assembly detail is chosen only after the installed system is verified. The drawing, field measurement, and approved shop detail should agree before a crew opens the roof.

We look at the upslope side of the curb, corner seams, fasteners, terminations, and the downhill discharge path. A stain near a skylight does not establish which joint failed, and a bead of sealant is not a substitute for a compatible flashing detail. Photograph each side and mark observed gaps or displaced material on a roof plan. If the opening has a condensation concern, keep that observation separate from a roof leak diagnosis. A test or opening should be authorized and its limits agreed before the crew proceeds. Record any concealed condition after exposure. A commercial roof leak investigation follows the water entry path, while a condition report preserves the larger area for the owner. This distinction helps avoid replacing a skylight or adding sealant before the roof-to-curb transition is understood.

A skylight scope often requires a roof opening, temporary cover, frame work, and final flashing in a defined order. Identify who removes or protects the glazing, who secures the opening, and who accepts the curb before roofing starts. The general contractor should establish fall protection, interior barricades, and a roof access route for each phase. We set a maximum daily opening and identify the person who checks the temporary cover at shift end. If electrical or mechanical work crosses the same area, coordinate the trade path before installing the finished membrane detail. For work near Mission Street or Geneva Avenue, land-use context does not answer property access questions; confirm staging and tenant controls with the actual project team. A skylight job in San Francisco gets its own sequence from that building's access and tenant rules.

Cost depends on curb perimeter, height, corners, sheet-metal fabrication, membrane transition, access, glazing coordination, and any substrate revealed after removal. A simple reseal is not equivalent to removing the existing flashing and rebuilding the tie-in. State the fasteners, materials, and sealant or weld method included, and identify the area where the proposal stops. If damaged insulation or deck is concealed, define the inspection point and authorization method for added work. This helps the general contractor align labor and glazing delivery without double-counting a trade. Where multiple openings are involved, label each one and distinguish repeated details from exceptions. A roof capital planning discussion can group future skylight work with other roof items, but it does not make the current scope less specific. The estimate should identify whether interior protection, disposal, and after-hours access are included.

The opening is the schedule-sensitive part of this work. We confirm the temporary cover, attachment, and inspection responsibility before removal, then plan how the permanent detail will be completed if weather or another trade interrupts the sequence. At SFO station USW00023234, the normal precipitation total for November through March is 16.76 inches out of 19.64 annually. That is station information, not a measurement on the project roof. It supports careful staging of open work during the cool season, not a claim that rain will occur on a particular date. Check surface condition and product instructions before completing a membrane tie-in. A storm damage repair plan is a separate scope if an event damages the opening. Record the weather hold, protection status, and next release time so another crew knows whether the area is ready.

Record: Photograph the finished transition

Closeout should show the curb after flashing, the membrane return at each corner, the completed seal or weld, and the condition of the adjacent roof. Keep glazing or framing sign-off separate when another trade owns it. List any surface not accessible, excluded interior work, and temporary protection that remains. The roof plan should identify the opening with a stable label, and photographs should show orientation rather than a collection of close details with no location. If a leak report continues, create a new investigation item rather than assuming the flashing work failed or the interior mark is resolved. The owner and general contractor can then compare the record with the work order. Share the opening dimensions, available details, roof plan, and trade schedule so we can define a waterproofing scope and coordinate the final handoff. Include photographs from before any temporary cover was installed, if available, and identify whether the roof team can access the underside of the curb. Those details can distinguish a flashing gap from an unresolved frame or glazing issue. Record who accepts the finished transition and where the closeout images will be stored for the next project phase. That last check should include a dated roof-plan mark, so a later service call can identify the exact opening without relying on a remembered location or an unlabeled photograph. Include the curb side, roof-zone name, and the direction of view so the image can be compared with the approved detail and subsequent work.

Commercial Roofing Questions

Does skylight flashing include glazing replacement?

Only when the proposal expressly includes it. Roofing flashing and glazing or frame work should have defined trade ownership, dimensions, and acceptance points.

Can sealant alone repair a curb leak?

That depends on the field condition and existing detail. The scope should inspect the curb, membrane return, fasteners, and corners before selecting a repair method.

How is an open skylight protected overnight?

The plan should identify the cover, attachment, responsible person, and end-of-shift inspection. The allowed opening size and duration need agreement before removal begins.

What if insulation is wet around the curb?

Document the area and obtain authorization before opening it. Measure and record exposed conditions, then price replacement as a distinct item if it falls outside the base scope.

What does the GC need before scheduling?

Provide curb dimensions, roof details, access and fall-protection rules, glazing or electrical dates, interior controls, and the person who accepts temporary protection.

Commercial Skylight and Penetration Flashing in Daly City, CA