Weatherstripping
Also called: weather seal, pile seal, brush seal
Quick answer: weatherstripping on a sliding door is the soft pile (a strip of short brush) that runs along the panel edges and where the two panels overlap. Many strips also have a thin plastic fin in the middle. Together they close the small gaps a sliding panel needs to move.
- Interlock pile, where the two panels overlap when closed
- Lock-side pile, where the sliding panel closes against the frame
- Fin, a thin plastic blade inside the pile that blocks air
- Backing, the base strip that slides into a slot in the frame
How to check your weatherstripping
Work in this order. The first two checks take a few minutes and need no tools.
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Feel for air on a windy dayRun your hand along the edges and the middle overlap with the door closed and locked.
Safe to do yourself
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Look at the pileFlat, matted, torn or missing sections mean the strip no longer touches.
Safe to do yourself
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Check with a light at nightOne person shines a flashlight along the edges from outside. Light coming through marks a gap.
Safe to do yourself
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Replace the worn stripsMatch the old pile. Strips on the panel itself mean lifting it out of the track.
Take care: two people
Fix it yourself or call a pro
- Safe yourselfVacuum dust out of the pile and replace strips you can reach in the fixed frame without moving the panel.
- Take careMany strips sit in the panel edges, so the panel has to come out. Glass panels are heavy and tempered glass can shatter: two people at least, or call a pro.
- Call a proDrafts that stay after new strips (often a panel out of line), water coming in, or pile you cannot match.
More on this: why a sliding door is hard to open, and how to make it slide easier.

Types of sliding door weatherstripping
Most sliding patio doors use pile with a fin along the moving edges.
Feeling a draft at the door?
Select Sliding Doors replaces worn weatherstripping as part of sliding door repair across Dallas-Fort Worth. Mon to Sat, 7am to 10pm.
Questions people ask
How do I know which weatherstripping to buy?
Pull out a short piece of the old strip, or measure it. Note the backing width, the pile height and whether it has a fin. Take the sample with you, or have a technician match it.
Can new weatherstripping make the door hard to slide?
Yes. Pile that is too tall presses hard on the frame and the door drags. If a door got stiff after new strips, check the size first. More causes in our guide to a sliding door that is hard to open.
Can I use foam tape instead?
Not on the moving edges. Foam tape is made for doors and windows that press shut. On a sliding panel it tears, drags and soon falls off. Use pile made for sliding doors.
Related terms
Photo: own media library. Diagram: Select Sliding Doors.