Ensuring Exterior Doors are Watertight at their Base


Any opening to a home’s envelope creates a potential area to allow water to penetrate the home. Exterior doors are one of those openings notorious for this.  


My Job: 


My job during an inspection is to locate any points of water entry into the home and evaluate the damage that has resulted. Exterior doors are a primary inspection point due to their potential of water penetration. Water penetration at exterior doors, when it goes unnoticed, can result in not only flooring and trim damage, but also floor framing damage. For this reason, while in the foundation, I am required to move all insulation away under exterior doors to examine the framing. The photos below illustrate common results related to water penetration at the exterior doors: 





Ensuring your doors are flashed properly at their base is the best defense against water penetration into the home and floor framing. The type of flashing needed to ensure your exterior doors are watertight is called sill pan flashing. Just like it’s name reveals, this type of flashing creates a pan shape in order to route any water that penetrates the threshold, door frame, and trim out and away from the home. Unfortunately, this flashing is many times improperly installed or missing altogether. The link below provides best practice details regarding flashing around windows and doors. 






Water is a home’s worst enemy and often results in hidden damage before discovered. However, flashing is an easy way to prevent water penetration. It just needs to be installed and installed properly. If you are wondering if your exterior doors are watertight, it would be my pleasure to assist you. The inspection would include an inspection of the doors from the interior, exterior, and foundation if accessible. When you really want to know, call Duncan Home Inspection Services.