How to Replace a Shower Door Bottom Sweep
Quick answer
Replacing a bottom sweep is a 15-minute job: pull the old sweep off the glass, clean the edge with rubbing alcohol, cut the new sweep to the door width minus 1/16 inch with a fine-tooth hacksaw, press it on starting at one end (a trace of soapy water helps), and let it sit before showering. The only real skill is buying the right size first.
Last updated: · Data reviewed: · Source: C.R. Laurence technical resources
Before you start: confirm the size
Ninety percent of failed installs are sizing, not technique. You need the glass thickness (channel size) and the closed-door bottom gap (wipe height ≈ gap + 1/8–1/4 in). If either number is a guess, measure now — the door is about to be bare anyway. The Seal Finder turns the two numbers into a shortlist.
Tools and supplies
- New sweep, correct channel size and wipe height
- Fine-tooth hacksaw (24–32 TPI) or miter shears; a miter box helps square cuts
- Tape measure and a marker
- Plastic razor or old credit card for scraping residue
- Isopropyl alcohol and a rag
- A drop of dish soap in a cup of water (bottom sweeps only)
Step by step
- Remove the old sweep. Open the door over a towel. Grip one end of the old sweep and peel it steadily off the edge; brittle vinyl may come off in pieces — pull each with pliers.
- Clean the glass edge. Scrape soap film and any adhesive with a plastic razor, then wipe the edge and an inch of both faces with isopropyl alcohol. Let it dry fully.
- Measure the door width. Along the bottom edge, end to end. Your cut length is this width minus 1/16 in so the sweep clears the side seals.
- Mark and cut the new sweep. Mark with the channel facing up. Cut slowly with the fine-tooth hacksaw; if the sweep has a drip rail, keep the factory end at the rail's drain side and trim the other end.
- Orient it correctly. Wipe angles into the shower; drip-rail fin faces the bathroom side with its lip up. Copy the old sweep's orientation if in doubt — photograph it before removal.
- Press it on. Wet the channel lightly with soapy water. Start the channel over the glass at one end and walk your palm along the door, seating it fully as you go. It should take firm, even pressure — never hammering.
- Let it settle, then test. Give a lubricated install a few hours (ideally 24) before the first shower, then run water at the door and check both bottom corners with a paper towel on the bathroom floor.
Mistakes to avoid
- Cutting before test-fitting the channel on a corner of the door.
- Lubricating a vertical side seal the same way — vertical seals go on dry or they creep down.
- Trimming the flexible wipe shorter with scissors; a cut fin edge waves and leaks.
- Installing the drip rail fin pointing down or outward — it must pitch back into the shower.
- Forcing a channel that resists: that is a size mismatch, not a strength test.
Post-install check
- Glass thickness at the bare edge — pull back a section of the old seal first (1/4″, 5/16″, 3/8″, or 1/2″)
- Bottom gap from glass edge to threshold at the HINGE end, door closed
- Bottom gap at the HANDLE end, door closed — note any difference
- Door width along the bottom edge (for trimming the new seal)
- Where the water actually exits: under the door, off a bottom corner, or down a vertical edge
- Photo of the old seal's cross-section before removing it
- Door swings freely with light, even wipe contact — no hard drag
- No daylight visible under the door at either end when closed
- Drip rail (if any) pitches slightly into the shower
- Corners dry after a 2-minute spray test at the door line
- Offcut kept and labeled with glass size for future reference
Frequently asked questions
Do I need adhesive or silicone to hold the sweep on?
No. A correctly sized channel friction-fits the glass. Reaching for glue is the classic symptom of a channel one size too big — exchange it for the measured size.
How do I cut a sweep without a hacksaw?
Sharp miter shears or heavy scissors handle soft all-PVC sweeps; rigid polycarbonate channels really want a fine-tooth saw. Cut on the waste side of your mark and deburr with sandpaper.
The door drags after installing the new sweep — did I do it wrong?
Light, even contact is normal for the first week while the fin conforms. Hard drag means the wipe is more than about 3/8 inch taller than the gap — swap to the correct height rather than living with it.
How long before I can shower?
If you installed dry, immediately. If you used soapy water, give it several hours — ideally overnight — so the channel stops creeping and grips fully.