How to replace bathroom tiles on solid brick wall?

Question

Hi folks. Back for more advice. I am gonna try help someone sort this bathroom but have never done tiling before. Assuming this cracking and crazing is probably caused by moisture (and possibly movement).

I don't need it to be 100% perfect but need to see if i can repair/replace what's going on here. Looks to me like zero silicon in that corner wall join also which is probably not helping and may even be the main cause of what's going on.

Assume the process is something like.

- Remove grout with grout tool/saw

- Remove tiles (think i can get similar so not looking to replace whole wall but rather just what is required. I assume I smash and or pry them off?

- Clean up the wall behind the tiles… it's solid brick. So assume clean glue etc off the some sort of waterproofing?

- Then apply glue/tile cement, whack the tiles on, re-grout, silicon that corner join and the bath join and bob's you're aunty?

I know there's some good how to tile/grout guides on here, but any other step by step clues for a newbie would be so very much appreciated. Thanks all.

MitchellMc · Answer

Hi @Sputnik,

I'm not aware of a guide we have specifically covering waterproofing over solid brick walls.

The process is generally very similar to waterproofing plasterboard. The brickwork is cleaned and any holes or uneven areas are repaired, then a suitable primer is applied (if required by the waterproofing manufacturer). After that, bond breakers are installed at all wall junctions and corners, and the liquid waterproofing membrane is applied in the required number of coats to achieve the specified thickness before tiling.

One thing that might work in your favour is that the brick wall may actually have been sheeted first. It's quite common for installers to batten or direct-fix fibre cement sheeting over masonry to create a flatter substrate before waterproofing and tiling. If that's the case, the waterproofing membrane will most likely be on the face of the sheet rather than directly on the brick.

Unfortunately, you generally won't know what's behind the tiles until you remove one. Once you can see the substrate, it'll give you a much better idea of how the wall was originally constructed and whether a localised repair is likely to be practical.

Please let me know if you have any other questions.

Mitchell

Sputnik · Answer

Thanks for this mate. Is there a link to how you waterproof a wall that isn't plasterboard? I've only ever dealt with and seen waterpoofing on plasterboard so no real idea what's going on behind tiles when it's on a solid brick wall?

MitchellMc · Answer

Hi @Sputnik,

You've basically got the right idea. The general process is:

* Remove the grout around the damaged tiles.
* Carefully remove the tiles, usually by breaking them and prying the pieces off.
* Clean the substrate of old adhesive.
* Check the condition of the wall and waterproofing.
* Apply new tile adhesive, install the replacement tiles, grout once cured, and use silicone in all change-of-plane joints such as corners and where the tiles meet the bath.

The biggest thing to be aware of, is the waterproofing. In my opinion, that's the number one issue with replacing individual tiles.

There's a chance you'll get lucky and the tile adhesive lets go cleanly, leaving the waterproofing membrane intact. Unfortunately, that's not usually what happens. More often than not, the waterproofing comes off with the tile or gets damaged while you're prying it off.

The problem is that waterproofing isn't really designed to be patched in small sections. While some licensed waterproofers may be prepared to carry out a localised repair, others won't because waterproofing is intended to be one continuous membrane from the floor and up the walls. Once that continuity is broken, you're relying on a repair rather than the original system.

So, before you start, I'd decide which path you're comfortable with. If you're happy with a patch repair, then replacing a few tiles may be acceptable. If you want to know the waterproofing is back to its original standard, the proper approach is usually to remove all the tiles, re-waterproof the entire area, and then re-tile.

Also, the lack of silicone in that corner does stand out. Internal corners should be silicone rather than grout to allow for movement, so that's definitely something to address when you put it back together.

Here are some helpful guides: How to remove tiles and How to tile a wall.

Please let me know if you have any questions.

Mitchell