When I purchased my current project my thought was to completely remodel the townhome. This meant removing the entire interior down to the studs. During this process I discovered several things that made me glad that I made this decision.
Doors, Windows, and other structures require flashing when they are installed into exterior walls. Flashing is a sheet of thin, impervious material used to prevent water penetration or seepage into a building, and to direct the flow of moisture in walls. You can’t see flashing once the interior walls or exterior siding are installed. This fact allows some installers to cut corners.
Apparently, that is what happened when my townhouse was constructed. A window facade on the garage was never properly flashed, as were other spots, such as an outside electrical outlet. As an aside, the electrician who installed the outlet didn’t even bother to make a proper opening. Instead, he pounded a crude hole using his hammer.
You can see the extensive amount of black mold that grew as a result of poor construction habits. To remedy this problem the siding will need to be removed, and new norboard will need to be installed. Proper flashing of an opening is both simple and inexpensive. With that said, I have seen this problem many times when I have worked on remodeling jobs. Cutting corners can cost the owner quite a bit of money over time. When choosing a contractor remember that price should be only one factor in determining your choice. Quality counts.