The short answer
Check the Weatherstripping
The weatherstripping along the bottom and sides of the sliding door is the first line of defense. Over time, it can crack, compress, or pull away from the frame. When that happens, rain can seep through the gap and run onto your floor.
Look for worn or missing strips. Run your hand along the seal to feel for gaps. If the rubber is hard or brittle, it likely needs replacing. You can buy new weatherstripping at a hardware store and slide it into the track. A tight seal is the simplest fix for many leaks.
Inspect the Track and Rollers
If the door does not sit evenly in the frame, water can find a path. Dirt, debris, or a bent track can cause the door to tilt, leaving a larger gap on one side. The rollers on the bottom of the door can also wear down, making the door sag.
Clean the track thoroughly and check the rollers for damage. You can adjust the rollers with a screwdriver to raise or lower the door. When the door sits level and closes snugly, the seal works better. If the track is bent or rusted, you may need to replace it.
- Wipe the track with a damp cloth to remove grit
- Vacuum out leaves and dirt from the track
- Look for rust or corrosion on metal parts
- Test the door by closing it and feeling for air leaks
Clear the Weep Holes
Sliding doors have small drainage holes, called weep holes, at the bottom of the frame. These holes let water escape to the outside. If they get clogged with dirt or debris, water backs up and spills over the threshold into your home.
Find the weep holes on the outside of the door frame. Use a small wire or pipe cleaner to gently clear any blockage. You can also flush them with water from a hose. Keeping these holes open is a key step to stop indoor pooling during heavy rain.
Look at the Flashing and Exterior Caulk
The flashing above the door is a metal or vinyl strip that directs water away from the top of the frame. If it is missing or damaged, rain can run down the wall and behind the door. The caulk around the door frame can also crack, letting water in.
Inspect the area above the door from outside. Check that the flashing is firmly attached and slopes downward. Reapply exterior caulk around the frame if you see gaps. This is a job you can do yourself, but if the damage is extensive, a local water damage pro can help.
Consider the Water Damage Inside
If your door has leaked for a while, water may have soaked into the drywall, the subfloor, or the door frame itself. You might notice soft spots, peeling paint, or a musty smell. Catching the leak early prevents more serious structural issues.
After you fix the source, dry out the affected area thoroughly. Use fans or a dehumidifier to remove moisture. If you see signs of mold or the damage is widespread, it is wise to have a professional assess the situation. They can also check for hidden moisture in the walls.
For a thorough inspection, you can contact a water damage inspection service. They use moisture meters to find hidden wet areas. If the leak has caused rot in the door frame, a door frame repair service can replace the damaged wood.
- Feel the wall below the door for dampness
- Look for dark spots or bubbling paint
- Check the floor for warping or softness
- Notice any musty or mildew smell
- Use a fan to dry the area after fixing the leak
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Call Now (425) 407-5186Frequently asked questions
Can I fix a sliding door leak myself?
Yes, many leaks are caused by worn weatherstripping or clogged weep holes, which you can fix with basic tools. Start with a thorough cleaning and seal replacement. If the leak persists or you see water damage inside the walls, call a professional.
Why does my sliding door leak only during heavy rain?
Heavy rain often comes with wind, which pushes water into small gaps. The volume of water can also overwhelm the weep holes if they are partially blocked. Check the seals and drainage after every storm to keep the door watertight.
What should I do if water has damaged the drywall near the door?
Dry the area as soon as possible with fans or a dehumidifier. If the drywall is soft or stained, it may need to be cut out and replaced. A water damage pro can assess the extent and recommend the right repair.