How do I stop a shower screen leaking?

A puddle outside a shower is usually blamed on the silicone, and often the silicone is fine. Working out the actual path the water takes saves redoing a joint that was never the problem.

Safety

Step by step

1. Find where the water arrives, not where it leaves.Dry everything, shower normally, then look immediately. Water at the front edge of the tray is a seal issue; water appearing at the wall end is usually the vertical silicone or the wall channel.
2. Check the plastic seal strip first.The clear strip clipped along the bottom or leading edge of the glass hardens, splits and stops touching the tray. It is the most common cause and the cheapest fix — they clip off and on, and replacements are sold by profile.
3. Take the old strip with you to buy a replacement.They come in several profiles and glass thicknesses and look confusingly similar. Matching by eye from memory rarely works.
4. Inspect the silicone at the tray junction.Look for black spots, lifting edges or a gap you can slide a blade into. Silicone that has come away from the tray on one side lets water straight underneath even though it looks continuous.
5. Reseal properly if the silicone has failed.Cut and scrape every trace of the old bead out, clean with a solvent-based cleaner, let it dry completely, then run one continuous bead of sanitary silicone and tool it. Old silicone left behind is why reseals fail.
6. Seal on the inside only, not both sides.Sealing the outside of the tray-to-screen joint as well traps any water that does get in, so it sits there instead of draining back. Seal the wet side and leave the outside open.
7. Check the screen is square and the tray is level.A tray that has settled, or a screen fitted slightly out of plumb, leaves a gap that widens towards one end. A spirit level on the tray edge shows this quickly. It needs the screen refitting, not more sealant.
8. Look at the wall channel and its fixings.Water tracks down inside the vertical channel and out through the screw holes if the channel was not sealed to the tiles at the back. Removing, sealing behind and refitting the channel fixes it.
9. Consider how the water hits the screen.A shower head angled straight at the join, or a hinged door closed against the flow, drives water at a gap that would otherwise cope. Repositioning the head is sometimes the whole fix.

Tips

• Fill the tray with a couple of centimetres of water and leave it before resealing. If the level drops, the leak is the tray or waste, not the screen.
• Give silicone the full cure time on the tube before using the shower. Using it after a few hours is the commonest reason a fresh bead fails.
• Wiping the bottom seal dry after showering roughly doubles how long the strip lasts.

If it doesn't work

Questions people ask