Home Categories Send inquiry

How to flash under sliding door


Sliding doors are a popular choice for many homeowners due to their beauty and functionality. However, when it comes to weatherproofing and preventing water intrusion, paying attention to the flashing underneath your sliding door is crucial. Properly waterproofing the area ensures your home is protected from water damage, mold growth, and other potential problems. In this blog, we’ll guide you through the process of properly installing flashing under your sliding door to provide your home with enhanced protection.

sliding door screen door

The importance of waterproofing panels under sliding doors:

Flashing is a technology used to create a waterproof barrier that directs water away from vulnerable areas of your home. The area beneath sliding doors is particularly susceptible to water intrusion due to its direct exposure to the elements. Improper or insufficient flashing can cause costly damage and compromise the structural integrity of your home. By following the steps outlined below, you can ensure a tight seal and minimize the risk of water penetration.

Step 1: Prepare the area:

Before installing flashing under your sliding door, it is important to prepare the area properly. Start by cleaning the surface underneath the door thoroughly. Remove any dirt, debris, or old caulk to ensure a smooth, secure connection to the flashing material.

Step 2: Choose the appropriate flash:

Choosing the right waterproofing material is critical to effective waterproofing. There are many types of flashings available, such as adhesive membranes, metal or rubber flashing strips. Consider climate and local building codes when making your decision. Make sure the flashing material is durable, weather-resistant, and specifically designed for use with sliding doors.

Step 3: Install the waterproof board:

Cut the waterproofing material to length so that there is adequate overlap on each side of the door. Begin by securing one end of the flashing to the exterior wall near the sliding door. Make sure it is securely attached and sealed. Gently press the flashing against the wall to ensure proper adhesion.

Continue laying waterproofing material along the surface below the door, keeping a slight slope from the door to facilitate drainage. Make sure the flashing extends beyond the vertical legs on either side of the door frame to create a complete barrier. For added protection, apply a thin layer of caulk to the back of the flashing before pressing it into place.

Step 4: Seal and test:

After installing the flashing, seal the edges and any gaps using a high-quality caulk. This helps prevent water from seeping under the flashing. Use a caulking tool or your fingers to smooth the caulk area to ensure a neat look.

Finally, test the flashing by carefully pouring water onto the surface near the sliding door. Observe whether the water on the door is drained normally and whether there is leakage or water seepage. If any issues are found, recheck the flashing installation and re-caulk if necessary.

Taking the time to properly waterproof under your sliding door is a critical step in protecting your home from water damage. By following the simple steps above, you can increase the protection of your home and enjoy the benefits of waterproof sliding doors. Remember, proper flashing not only ensures the longevity of your sliding door, it also ensures the structural integrity of your home.