Madison Roof & Leak
Janesville, Wisconsin

Skylight leaks in Janesville

Skylights leak at the flashing kit or the perimeter seal far more often than through the glass itself. The unit sits proud of the roof plane and interrupts the water path, so everything depends on how the flashing was stepped into the surrounding courses. Water showing at the corners of the opening inside is the classic sign. Condensation on the inside of the pane is a different problem entirely — that is ventilation, not a leak, and sealing the outside will not touch it.

Call (706) 696-1888 Rock County

What the job involves

  • Inspection of the flashing kit, head, sill and side step flashing
  • Check of the glazing unit seal where condensation is suspected
  • Reflashing rather than resealing where the kit has failed
  • Ventilation check if the moisture is condensation rather than ingress

Signs you need it

  • Drips at the corners of the skylight opening
  • Staining on the plasterboard reveal around the window
  • Moisture between the panes of the glazing unit

Why roofs fail in Janesville and Rock County

Janesville has a winter long enough and cold enough that ice damming, not storm damage, is the dominant cause of roof leaks. The mechanism is heat loss rather than weather: warm air escaping into the attic melts snow on the upper roof, the meltwater runs down and refreezes over the cold overhang, and the resulting ridge of ice backs water up beneath the shingle courses until it finds a way in. The roof itself is usually in perfect condition. Repeated through a Rock County winter, freeze-thaw also works every flashing joint progressively looser, and spring brings hail and straight-line wind on top. The reason this matters is that fixing an ice dam leak by working on the shingles does not work — the problem is insulation and ventilation, and that is a different job.

Janesville has a population of about 63,575, and the housing stock here sets the pattern for what fails first on a roof.

Questions about skylight leaks in Janesville

Is condensation on my skylight a leak?

No. Moisture on the room-side face of the glass is warm damp air meeting a cold surface, and it is a ventilation problem. Moisture trapped between the panes means the sealed unit has failed and the glazing needs replacing. Neither is fixed by working on the roof.

Can an old skylight be reflashed, or does it need replacing?

If the unit itself is sound it can be reflashed, which is far cheaper. Replacement makes sense when the frame has rotted, the seal between panes has gone, or the unit is old enough that matching flashing is no longer available.

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You will get a straight answer on whether Janesville needs someone out today or whether it can wait — before anyone quotes you for anything.

Call (706) 696-1888
Call (706) 696-1888