What Can We Tell From These Photos? (Case Study 19)

Posted by in Case Studies, Roof, Simple Forensic Methods, Wood | May 13, 2019


Figure 1 Roof exhibits deep trough before scupper through parapet wall.
  1. The roof surface exhibits a deep trough near scupper through which the roof drains.
  2. The roof runoff can’t drain off the roof until it fills and overflows the trough.

Figure 2 Roof membrane partially fits trough and trough
exhibits previous patching, heavy deposits, and plant growth.
  1. The trough has been present for months, as evidenced by the growth of grass
  2. The trough has been present for years, as evidenced by the general fitting of the roof membrane and the patching to the warped surface of the trough.  
  3. The trough has been present for years, as evidenced by the heavy deposits on the membrane where roof runoff and sediment from the roof accumulate.
  4. The leakage at the trough was known for years, as evidenced by the patching of the roof membrane at the trough.
  5. The presence of the trough was known, as evidenced by the previous patching at the trough.
  6. The trough became deeper recently, as evidenced by the relatively clean fractures at the tears and separations in roof membrane at the trough.
Figure 3 Original roof framing shored with newer lumber.
Beam in newer framing is fractured.
  1. The presence of the trough was known, as evidenced by the newer lumber that shores up the older wood framing at the trough.
  2. The presence of the trough was known for years, as evidenced by the severe decay of the lumber in the newer framing.   
Figure 4 Lumber in beam of newer shoring exhibits severe decay,
as shown by penetration of awl.
  1. The more recent deepening of the trough was due to the fracture of newer beam in the shoring. 
  2. The newer beam fractured due to the combination of severe decay, as evidenced by the splintering of the wood at the fracture and the depth of penetration of awl at the fracture, and the additional weight of the ponding water in trough, which had been accumulating during every sizable rainstorm.

Disclaimer