HGTV's Mike Holmes Reveals How You Can Keep Water From Seeping Through Your Door

Aside from giving the first impression of a home, a door is crucial for security and weather protection. That's why HGTV's Mike Holmes is encouraging homeowners to consider long-term protection when building the doors of their property. In a video he posted on Facebook, the celebrity contractor featured an often-overlooked component in exterior door installation: door flashing or waterproofing. "[It's] incredibly important to keep water from sneaking inside your house," he wrote in the caption. The short clip shows a newly installed door flashing in a project he's working on.

One of the biggest mistakes people make when choosing a front door is focusing solely on the aesthetics and style of the unit without thinking about structural considerations like proper flashing and sealing. Whether concealed or exposed, flashings serve as waterproof barriers that redirect moisture from critical areas of the door and the adjacent walls. Doing so can ensure the structural integrity and longevity of the door, regardless of the weather or moisture concentration outside.

As one of the largest openings in a home or building, doors are vulnerable to moisture intrusion, especially during the rainy season. When not flashed correctly, water can seep past the seams and gaps and infiltrate the wall cavity. When this cycle repeats several times over a period, the moisture can cause serious structural degradation, wood rot, and even mold growth. The only way to address these issues by then would be to spend on expensive repairs that might involve replacing the entire door.

To properly flash a door, start by preparing the rough opening or the framed space into which the door is installed. Cover it with house wrap, sealing the jambs, sill, and head to create the first line of defense against moisture. Next, install the flashing tape. You can choose between a self-adhering butyl or asphalt-based material. The former is a better option since it can withstand extreme heat and is easier to use, especially if you're doing multiple doors. Apply the tape around the perimeter of the opening to create a watertight seal.

After taping, carefully level and fasten the door in place. One of the most important but often neglected steps is installing a drip cap or pan flashing over the door. This piece of flashing, which may come pre-installed or be fabricated from aluminum coil stock, is designed to redirect water away from the top edge of the door where leaks are most likely to form.

Just like doors, windows also need flashing for the same purpose of preventing moisture from infiltrating. In fact, understanding the reason there's water on the inside of your windows often boils down to flashing failures or poor sealing. Proper flashing not only prevents external moisture but also supports healthy air circulation that reduces condensation risks. While many people turn to dehumidifiers, there are also tricks to prevent window condensation without a dehumidifier, such as improving insulation and using properly installed vapor barriers.