Wrong place at the wrong time

Wrong place at the wrong time, or Leaks at the Roof-to-wall Interface

Moral: Proper construction detailing is essential between building systems.

Situation

A new retirement home was built a couple of years ago. It was a three story building. The roof consisted of asphalt shingles on a plywood deck. The octagonal front entryway had stone masonry cladding. The General Contractor was anxious to get the building “dried-in” so that the interior work could be done without concern of getting wet.

Mistake

The roofer was told to complete the application of the shingles before the stone mason laid up the wall. As a result, where the stonework extended above the roof, the mortar and stone was actually laid on top of the previously installed shingles.

Result

When it rained, the rainwater ran down the slope of the roof, under the stone and mortar and into the building. A gypsum board ceiling collapsed.

Lesson(s) learned.

There is no substitute for proper sequencing of construction work. The stone mason should have completed the wall before the roofer laid the shingles.

There is no substitute for proven construction details properly installed. The flashing between the roof and the wall cannot be left out simply because the roof is sloped.

Particular care must be paid to the interface between systems, i.e. between the roof and the walls. Each trade is responsible for their own work, but not for others’. Although there were several opportunities to prevent or correct this failure, no corrective steps were taken.