Due to the many facets of window design and assembly, window defect problems are common and can result in water intrusion. Problems can be the result of improper flashing installation, paper application, and improper use of sealants or lack thereof. The window itself may be defective in design and factory construction. Damage can be severe if not remedied immediately. Damages range from staining and cracking of interior drywall surfaces (especially on top of window sills), to structural member damage and ultimately dry-rot and mold infestation, if not addressed.