Why Is Water Coming in Through My Sliding Glass Door?

Sliding glass doors have small drainage holes along the bottom track that let rainwater escape to the outside. These holes can become blocked with dirt, leaves, or debris, causing water to pool and overflow into your home. You can clear them with a thin wire or a blast of compressed air.

If the holes are clear, look at the track itself. A bent or warped track can prevent water from flowing toward the drains, directing it instead toward your interior floor. Run a finger along the track to feel for any raised spots or damage that might redirect water.

• Use a straightened paper clip to probe each hole
• Flush with a hose from the outside while checking inside
• Remove any visible debris from the track groove
• Check both the top and bottom tracks for blockages
• Clean the track with a mild detergent and soft brush

The threshold is the bottom piece of the door frame that you step over. If it is cracked, rusted, or not level, water can pool on top and seep underneath. Check the threshold for any visible damage, and also look at the frame corners where the door meets the wall.

Water can also enter if the frame is not properly sealed to the surrounding wall. Gaps around the exterior of the frame allow rain to penetrate and run down inside. Inspect the caulking or sealant on the outside edge of the door and reapply if you see any cracks or missing sections.

Sometimes the problem is not the door itself but the ground outside. If the patio or deck slopes toward the door, rainwater will run directly at the threshold and overwhelm the drainage system. Check the grade of the ground outside your door and see if water pools there during rain.

You can often fix this by adding soil or a small drain to redirect water away from the door. For a quick test, pour a bucket of water on the exterior side and watch where it flows. If it heads toward the door, you need to adjust the landscaping or install a drip edge.