How to Clean Clogged Window Weep Holes to Prevent Water Damage

Why Window Weep Holes Matter

If you have vinyl or aluminum sliding windows, you might have noticed small, rectangular slots on the exterior bottom of the frame. These are weep holes. They serve a critical purpose: draining away rainwater that collects in the window tracks during heavy storms. When these tiny passages get clogged with dirt, pollen, and dead bugs, water backs up, overflowing into your drywall, causing rot, mold, and expensive structural damage. Cleaning them takes less than 15 minutes and requires only basic household items.

Tools You Will Need

• A vacuum cleaner with a crevice tool or brush attachment
• A small, flexible wire (like an unbent paperclip, a zip tie, or a thin wire hanger)
• An old toothbrush or small cleaning brush
• A cup of warm water

Step 1: Locate the Weep Holes

Go outside and look at the bottom exterior frame of your windows. You should see one or two small, horizontal rectangular slots. Some windows have tiny plastic flap covers over them to keep bugs out; if yours does, gently lift or pop the flaps off with your fingers or a flathead screwdriver so you can access the hole.

Step 2: Vacuum the Window Tracks Inside

Before poking at the external holes, clean the inside tracks first. Slide the window fully open. Use your vacuum's crevice tool to suck up loose dirt, leaves, and insect debris. If you skip this step, flushing the weep holes later will just wash interior dirt into the drain, creating a muddy clog.

Step 3: Scrub and Clear Inside Debris

Use an old toothbrush to loosen stubborn, caked-on dirt in the corners of the track. If your window has removable track inserts, pop them out to expose the drain entry holes underneath. Vacuum up any newly loosened dirt.

Step 4: Probe the Weep Holes

Take your unbent paperclip, zip tie, or wire hanger and gently insert it into the exterior weep hole. Wiggle it around to break up any packed dirt, spider webs, or debris. Push it in as far as it comfortably goes, then pull it back out. Repeat this for the interior drain holes located inside the track.

Step 5: Flush and Test the Drain

To ensure the pathway is completely clear, pour a cup of warm water directly into the interior window track near the drain hole. Watch the exterior weep hole. The water should flow out freely and quickly. If it pools in the track or trickles out slowly, there is still a clog. Use your wire probe to gently clear the path again while pouring water until it runs clean.

Step 6: Reattach Flaps and Maintenance

Once the water drains freely, snap any plastic weep hole covers back into place. To prevent future clogs and potential water damage, make it a habit to vacuum your window tracks and check the weep holes every spring and autumn.