How to Fix a Leaking Shower Door Bottom Sweep

Short answer: a leaking shower door bottom sweep is almost always fixable without replacing the door or the glass. Find the escape point first, then check three numbers before you order: the glass thickness, the gap between the door and the threshold, and the angle the door closes at. The bottom sweep itself is a push-on extrusion that trims with scissors and fits without adhesive, so the repair is a one-evening job rather than a service call.

Why the bottom sweep fails first

In a frameless enclosure there is no frame to divert water. Every drop that leaves the shower travels past a seal, and the bottom sweep carries the largest share of that work because it sits on the one edge where water is deepest and where gravity is on its side. It is also the seal that takes the most mechanical abuse: it is compressed every time the door closes, it scrapes across the threshold every time the door swings, and it is exposed to soap, conditioner and limescale on every use.

Three wear patterns account for nearly all failures. The extruded lip takes a permanent set and stops springing back against the threshold. The polycarbonate or PVC cross-section hardens and cracks after long exposure to hot water and cleaning products. Or the profile had never been a close fit to begin with — the installer trimmed a 12 mm profile to sit on 10 mm glass, or the sweep was cut a few millimetres long and now stands off the threshold at one end.

Find the escape point before you buy anything

Water travels along the underside of the sweep and along the glass before it drips, so the place it appears on the tray is rarely the place it entered. Dry the threshold completely, run the shower for two minutes, then look at where the first puddle forms and trace backwards. The table below maps each symptom to the part that is most likely responsible and to the action that actually fixes it.

The same logic applies when the leak has been running for months: the full guide to frameless shower door leaks covers what persistent leakage does to the substrate, the thresholds and the fixings behind the tile, which a sweep replacement cannot undo.

Measure three numbers, then choose the profile

The sweep you need is defined by geometry, not by brand or by the shape of the old strip. Take three measurements with the door closed and the glass clean.

Glass thickness. Measure the panel with a caliper, at the edge where the profile grips, not in the middle where an earlier paint or film may sit. Zimmor lists the seal range across 6 mm (1/4″), 8 mm (5/16″), 10 mm (3/8″) and 12 mm (1/2″), and the models are specific to each: the 5706 seal is published as Z-5706-6mm, Z-5706-8mm, Z-5706-10mm and Z-5706-12mm for the corresponding glass, and the H-profile jamb family is published as P140HJ, P516HJ, P380HJ and P120HJ for the same four thicknesses.

The gap under the door. Slide a rule under the closed door at both ends and at the centre. A profile rated for one glass thickness will not close a gap that varies across the width, so a floor that slopes needs a taller lip, not a thicker profile.

The closing angle. Stand outside the enclosure and look at the door when it is shut: a door closing flat onto a straight panel is a 180° condition, while a door closing into a corner return is typically 135°. Zimmor publishes that angle explicitly on the product: the 5703 is a 135° glass-to-glass profile, the 5706 and the 5711 are 180° glass-to-glass, and the 5701 and P912WS are glass-to-floor.

If the three numbers do not match a profile you already have, the choice is between PVC and polycarbonate rather than between suppliers. PVC is the softer, more forgiving extrusion and is the usual choice when the door needs to conform slightly to an uneven threshold. Polycarbonate holds its shape better and stays clear longer under hot water, which matters where the same door is used many times a day. The full material and geometry decision, including magnetic and bulb profiles, is set out in the shower door seal specification guide; this article assumes that decision has already been made and the existing profile has simply worn out.

The replacement sequence that works on a hung door

The job can be done with the door still on its hinges. Working on the door in place avoids disturbing the hinge alignment, which is the most common way a sweep replacement turns into a hinge adjustment.

1. Stop the water and dry the enclosure. Twenty minutes with the door open is usually enough for the threshold and the glass edge to be genuinely dry. Adhesive residues and silicone do not behave predictably on a wet surface.
2. Pull the old profile off along its length. Push-on seals release by peeling from one end rather than by pulling sideways, which is what tears a lip and leaves fragments stuck in the channel.
3. Clean the glass edge, not the channel. Remove limescale and old silicone from the edge where the new profile will grip. A film of scale is enough to stop a push-on seal seating fully, and a seal that is not fully seated leaks along its whole length.
4. Cut with a sharp blade, square across the profile. Measure the old piece against the new one before cutting, and add 1–2 mm rather than cutting exactly to length: a profile cut to the millimetre will shrink back from the end over time, and that gap is where water tracks out.
5. Mitre the corner where a vertical and a horizontal seal meet. A 45° cut on both pieces gives a continuous joint. A butt joint that overlaps correctly also works, but a butt joint with a gap does not.
6. Seat the profile fully along its length with a firm thumb pressure from one end to the other, then run a fingernail along the glass line to confirm the channel has closed on both faces.
7. Test with water, not with a finger. Close the door and run the shower for two minutes with the head aimed at the door. If water still appears, recheck the corner joint and the gap under the door before assuming the profile is wrong.

Matching your leak to the profiles Zimmor actually publishes

Replacement is easier when the worn part can be identified by position rather than by memory. The table below maps the six leak positions from earlier to the published profiles that occupy them. Catalogue numbers are Zimmor’s own and are listed on the product pages; they are given here so that a photograph of the old strip can be matched to a current part.

Two practical notes come out of that table. First, the bottom sweep and the vertical jamb seal are different parts with different cross-sections; substituting one for the other is the most common reason a repair appears to fail. Second, the 5706 and the P380HJ family are both published in four thickness-specific versions, so a profile swapped between two doors of different glass thickness will not grip even if the appearance is identical.

When a new sweep is not the answer

Three conditions look like a sweep failure and are not. If the water appears under the hinge line rather than along the door edge, the vertical seal above the hinge has usually failed and the sweep is doing its job on water that never reached it. If the door no longer closes flush because the hinges have dropped, the resulting gap is a hinge adjustment problem, and the fix is covered in the shower door hinge adjustment guide rather than in the seal catalogue. And if the leak is at the base of a fixed panel, the part at fault is usually a glass clamp gasket or the floor fixing, not a profile along a door edge.

There is also a threshold condition that no seal can handle: an enclosure whose floor falls away from the tray. A profile can only close the gap it was cut for, and a sweep trimmed to a 6 mm opening at one end cannot also wipe an 11 mm opening at the other. Check the gap at both ends before ordering, and if it varies by more than a couple of millimetres, the threshold, not the seal, needs attention.

Ordering the right parts the first time

Seals are consumables, and they are ordered in a different pattern from hinges. Zimmor’s published FAQ states that regular products are held in material inventory with a lead time of five weeks, while a full 40 HQ container can be produced in around two weeks; custom glass and custom hardware accessories are both supported, so a non-standard enclosure does not force a standard seal. For a single worn sweep on a domestic door, that timing matters less than ordering both the bottom sweep and the side jamb seal in the same order, because they wear as a pair and a second order doubles the freight for parts that weigh almost nothing.

For a distributor or a hotel with a hundred identical doors, the calculation changes: the failure is predictable rather than accidental, and the sensible order is one profile per door position per glass thickness, held as a stock item. The clear PVC bottom seal 5701 and the high-clear PC seal 5706 cover the two most common positions, and the magnetic closure version is listed as the PVC seal with magnetic stripe 5711. The whole family, including the jamb profiles, is grouped under PVC shower seals and sweeps.

If the door is being replaced rather than repaired, the sequence that the seal has to fit into is the one described in the frameless shower door installation guide, and the wider hardware set — hinges, clamps, handles, support bars — is summarised in the frameless shower door hardware overview.

Frequently asked questions