Water leaking under exterior door threshold
Rainwater gets behind the siding and travels down to pool beneath the threshold even when flashing and weather stripping are properly installed. This hidden moisture can eventually rot the subfloor and joists if the source—such as a clogged gutter or water running along the foundation—isn't found and stopped.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Applying silicone under the threshold
- 2Checking j-channel and siding installation
- 3Checking for improper sill prep
- 4Removing the adjustable threshold strip, caulking underneath, reinstalling, and caulking the seams
- 5Replacing weather stripping
- 6Applying new silicone under the threshold
- 7Clearing gutters and downspouts
- 8Testing with a garden hose to trace the leak
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“I’ve been battling this for a year.”source ↗
“This! We had this happen because our gutter was clogged and dumping water in that particular spot.”source ↗
“I’ve been battling this for a year. Weather stripping is fine. There is silicone under the threshold. I pulled siding at the top of the door and the j channel is tucked correctly. The door also appears to be flashed correctly. Based of the pictures of the water draining along the foundation, I feel like rain water is still somehow getting behind the siding and coming in at the threshold.”source ↗
“I had a front door where everything needed to get replaced because it even rotted the joists and subfloor”source ↗
Where this came up
People with this problem also raised
- 2Water leaking behind new gutters and soffits
- 5Rot running from exterior deck up to door frame
- 3Basement window level with the ground water leak prevention
- 3Why is there water on the floor around my new water heater?
- 23Water keeps getting in the house during heavy rain
- 7Water spitting out of pump vent pipe