Check the door seals first
The magnetic or wipe seal strips that run down the edges of a hinged or sliding shower door are the first thing to inspect. These strips are designed to close the gap between the moving door and the fixed panel or frame, and they harden, split or shrink with age and repeated use.
If a strip is missing, cracked, or no longer sits flush against the glass, water will find that gap every time. Replacement seal strips are inexpensive and widely available for standard door profiles, and fitting a new one is usually a straightforward DIY job: the old strip pulls out of its channel and the new one clips or slides in.
Is the door actually hung level?
If seals look fine but water still escapes from one particular corner, check whether the door is hanging level. A door that has dropped slightly on its hinges, or was fitted slightly out of true, will open a small gap at the bottom or side that no seal can fully close.
You can check this with a spirit level along the top and side of the door frame. Minor adjustment is sometimes possible on hinges with adjustable screws, but persistent misalignment usually means the enclosure needs to come off and be rehung properly.
Is the tray level, not just the door?
A shower tray that is not perfectly level, even by a few millimetres, will pool water toward one side rather than draining evenly toward the waste. That pooled water sits against the door and screen edges for longer, increasing the chance it works its way underneath, even with good seals.
This is a common outcome of a tray that was bedded on an uneven subfloor without enough support underneath. If water always collects on the same side of the tray, this is worth checking before assuming the door itself is at fault.
Sealant on the wrong side of the frame
Sealant should generally run along the outside of a shower door frame or screen profile, on the room-side face, sealing the frame to the wall or tray. If sealant has only been applied on the inside face, water pressure from showering can push through gaps rather than being stopped at the outer seal.
Similarly, some enclosures rely on a specific sequence of sealant and trims, such as a drip strip along the bottom of the door, that directs water back into the tray rather than letting it run down the outside face of the glass. If this detail is missing, water tracks down the glass edge and drips onto the floor outside the enclosure.
The upstand and tile overlap detail
Where a screen sits against a tiled wall, there should be a slight overlap so the tiles sit in front of the tray upstand and any water running down the wall drains back into the tray rather than behind the tray edge. If this overlap is missing or was tiled the wrong way round, water can get behind the tray lip and eventually show up on the floor nearby, sometimes appearing similar to a door seal leak even though the door itself is fine.
| Symptom | Likely cause |
|---|---|
| Water at a specific gap along the door edge | Worn or missing seal strip |
| Leak from one corner only | Door hung out of level |
| Water always pools on one side of the tray | Tray not level |
| Water runs down outside face of glass | Missing drip strip or wrong sealant placement |
| Damp patch near wall away from the door | Poor tile-to-tray overlap detail |
What you can fix yourself and when to call someone
Replacing a worn seal strip, re-siliconing an external frame joint after removing and cleaning out the old bead, and checking tray level with a spirit level are all things a homeowner can do safely with basic tools and a bit of patience.
If the door is hung out of level and adjustment does not fix it, if the tray itself needs relevelling, or if the tile-to-tray overlap detail is wrong, the enclosure will likely need removing and refitting correctly, which is worth having a bathroom fitter look at rather than repeatedly resealing a symptom.
Where to read next
Questions we get asked most
How do I know if it is the seal strip or something else?
Run the shower and watch closely where water first appears outside the enclosure. If it is exactly where a seal strip is missing or damaged, that is very likely the cause. If water appears even with intact seals, look at door level, tray level or sealant placement instead.
Can I fit a new shower door seal myself?
Yes, in most cases. Standard wipe and magnetic seals for common door profiles are sold separately and typically just pull out and push into the frame channel, making this a manageable DIY task.
Why does water only leak from one corner of the door?
This usually points to either a dropped hinge causing a small gap at that corner, or the tray being slightly out of level so water pools and sits against that side for longer than it should.
Should the sealant be on the inside or outside of the door frame?
Generally the outside, room-facing side of the frame should be sealed to the wall or tray so the seal stops water at the outer edge. Sealant only on the inside face can allow water to push through gaps under normal shower pressure.
Do I need a whole new enclosure to fix a leaking shower door?
Rarely. Most leaks are solved by new seals, resealing correctly, or minor adjustment. A full refit is only usually needed where the door or tray is genuinely out of level and cannot be corrected in place.