Our shower is leaking slowly from somewhere, causing the ceiling of the room below to stain. We had the silicone sealant around the edge of the shower professionally replaced and it looks like a good job, but the leak persists.

The shower has no visible tray - it's basically a wet room with the floor tiles extending into the shower area. The room was fitted before we bought the house but I'd estimate it was probably done between 5 and 10 years ago. Some of the grout between the tiles on the shower floor is looking worn and cracked so I decided to regrout the floor in a further attempt to fix the leak.

After removing the metal drain cover and plastic insert, I found a thick layer of grout around the edge of the square plastic drain surround, which was quite flakey and crumbly, so I removed it all.

After doing so, I found a couple of holes between the tiles and the drain surround. Also, with this layer of grout removed, when I put the plastic insert back there is a large gap between it and the edge of the tiles.

My questions are: How should I fill the holes that I've found between the tiles and the drain surround? And how should I fill/seal the gap between the plastic insert and the edge of the tiles, given that the gap varies quite a lot in width and is quite wide wide in places, whatever I do will be visible when the job is finished, and the plastic insert is somewhat flexible when the metal drain cover isn't in place?

Hole 1 Hole 2 Gap

  • Do you have no grout between your tiles???
    – Huesmann
    Jan 7, 2023 at 15:20
  • 1
    @Huesmann I'm in the process of removing it at the moment. Jan 7, 2023 at 16:09

1 Answer 1


I believe there could be serious issues with the construction of the shower floor. Having water weep through the grout and around the drain is not unusual, however there should be waterproofing under the tile base that directs this to the drain. It sounds as if this is not a part of your shower system.

You can try to use a polyester caulk, like this vulkem to fill the gap between the drain and tile. Then find a grouting caulk that matches the color of your grout, ( it's more flexible than grout ) and fill in any grout lines that are open. Finally seal the grout with a quality sealer.

If the problem persists, you will have to remove the shower floor and repair from there.

  • What are the particular properties of the Vulkem that I should be looking for in an alternative? I'm struggling to find anywhere that sells it in the UK. I think you're right about the shower's construction. I expected there to be a tray under the tiles but there appears not to be. The whole room is tiled the same so retiling could end up being very costly. Jan 7, 2023 at 18:32
  • The Vulkem is a polyester caulk that stays flexible in a wide temperature range and is waterproof. It does not support mold growth like some silicones. It has a flow grade to it that makes it "flow" into voids better than silicones. Clean up does require mineral spirits..
    – RMDman
    Jan 7, 2023 at 22:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.