Every once in a while we run into a project that really forces us to bring every tool to the table.
This was one of them. The customer contacted us in an attempt to identify the cause of the moisture and mold growth on her siding. She’d already gone through two other investigators who had come to completely different solutions.
The first contractor told us her roof was failing. This was an understandable conclusion, because the home has a low angle roof, which are notorious for leaking. However, as you can see in the photo, the damage was occurring across a wide swath of the siding. This would be highly unusual if a roof leak were the cause. Additionally, no signs of moisture intrusion were noted on the interior side of the wall.
The second contractor believed the moisture was coming from the shower on the backside of the wall. Again, this was a reasonable assumption at first. However, we noticed two reasons this was unlikely.
First, notice the moisture buildup and mold growth occurring above the shower area. Second, the mold/moisture damage extends far to the right of the shower area.After ruling these issues out, we investigated the attic. This is where the surprises began. In the photo below, notice the coating of lint throughout the sheathing and framing.