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 the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 21.5× more often in r/HomeMaintenance than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Applying silicone under the thresholdDid this help you?
- 2Checking j-channel and siding installationDid this help you?
- 3Checking for improper sill prepDid this help you?
- 4Removing the adjustable threshold strip, caulking underneath, reinstalling, and caulking the seamsDid this help you?
- 5Replacing weather strippingDid this help you?
- 6Applying new silicone under the thresholdDid this help you?
- 7Clearing gutters and downspoutsDid this help you?
- 8Testing with a garden hose to trace the leakDid this help you?
- 9trying to use spray foam, caulk, or flashingDid this help you?
- 10Checking and verifying that the weep holes are not cloggedDid this help you?
- 11Pouring water into the door track to test drainageDid this help you?
- 12Sealing exterior cracks and gaps around the door with siliconeDid this help you?
- 13Considering sealing the small gaps around the edges of the track with siliconeDid this help you?
- 14cleaning out clogged weep holes at the bottom of the doorDid this help you?
- 15re-caulking the area above the door where it joins the sidingDid this help you?
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 ↗
“when it rains heavily enough water runs around the frame into our garage.”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 ↗
“Whenever it rains, water gets into the wall and carpet directly adjacent to the sliding glass door.”source ↗
“One thing I've noticed is that there are several gaps/seams in the sliding door track. I'm wondering if water could be getting through these gaps and making its way into the wall/floor.”source ↗
“However, when it did rain, I was getting water on top of my slider between baseboard and the sliding glass door.”source ↗
Where this came up
People with this problem also raised
- 4Water seeping under foundation in heavy rain
- 10Water leaking from roof corners and sidewalls
- 7Water leaking behind new gutters and soffits
- 6Water pooling in window tracks even after cleaning weep holes
- 5Rot running from exterior deck up to door frame
- 2Is water draining from under siding normal after heavy rain?