Some common causes of base-flashing problems are:
- Insufficient number of base-flashing plies.
- Improper base-flashing height.
- Insufficient protective coating, resulting in accelerated weathering and deterioration.
- Omission of cant strips, making the base flashing more susceptible to damage.
- Open vertical end laps or seams caused by insufficient sealing.
- Insufficient adhesion or movement between vertical surfaces and the roof deck, resulting in separation of base flashings from vertical surfaces.
- Loose insulation, causing base flashings to separate from vertical surfaces.
- Improper fastening of base flashings to walls or curbs, resulting in sagging or separation of the flashing from the vertical surface.
- Deteriorating substrates, causing base flashings to separate from the surface, or permitting water to enter behind base flashings.