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Hi there
I've been doing a lot of reading but struggling to get answers to a few questions.
1) I want to just directly tile over some very old shower tiles which I doubt have been waterproofed. Which primer and waterproofing product would be best to prepare the surface with? I have dunlop floor and wall tile adhesive.
2) I have the estillo arcylic shower screens. Is the best way to cut these to score them with a stanley knife and ruler and snap them?
3) I want to get a plumber to replace my side skew p trap toilet with a back to wall toilet and buld in like a box behind the toilet. Is that possible?
4) I have quite unlevel floors and am currently chipping the tiles of them. Next steps, I presume, are priming and then self levelling. Firstly I presume I can't skip some of the tile removal and just prime and level overtop of the remaining tiles? The tiles are 4mm thick and are stuck on well. I'm buying a chisel for my hammer drill but would love to just skip this step.
5) Secondly, what is the maximum height that I can self level? Does it depend on the brand? I was told it should only be a small amount but I'm reading it can be up to an inch?
Hi @hannahmg,
I’d like to start by clarifying that patched repairs to walls in wet areas, such as what you’ve done with the marine plywood, aren’t generally considered standard practice. In a shower-over-bath setup, the waterproofing system needs to form a continuous, unbroken barrier from the edge of the bath right up past the shower outlet. However, I do note that you do not believe there is currently a waterproofing layer under the existing tiles.
If you’re already tiling over two existing layers of tiles, the wall thickness will increase substantially. This can push your plumbing fittings too far back inside the wall, meaning your taps may no longer reach through to the plumbing work behind the tiles. In many cases, a plumber would need to extend the fittings forward to suit the new tile depth, which is worth confirming before you start. Another concern I have is whether the original tile adhesive has enough holding force to support three layers of tiles.
Given all this, my recommendation would be to remove the existing tiles (both layers), repair the wall properly with cement sheeting, waterproof it to code, and then retile. It’s a bigger job upfront, but it ensures the work is watertight, compliant, and long-lasting, unlike trying to patch and waterproof over a mixed surface, which is very difficult to make reliable.
If you do decide to go ahead with your current plan, what you've described would be the way to do it.
Please let me know if you have any questions.
Mitchell
It would be cement Villaboard sheeting, which is what's used as a base for tiling in bathrooms @hannahmg. The type used on walls is typically around six millimetres thick, so hopefully, you won't need to cut into the window frame.
That said, the whole idea of patching small sections on a wall in a wet area isn’t standard practice. If there’s damage or a section that needs replacing, the correct approach is to remove all the tiles in that area, repair the wall behind it properly, and then start again with new sheeting and waterproofing. A handyperson would likely be able to replace the panel.
The method you described above is designed for sealing joints between continuous surfaces, such as wall-to-wall or wall-to-floor junctions, not for joining around a small repair panel. I’d be cautious about paying a trade to install a small piece of cement sheeting in that spot, as it will always remain a compromised section. The membrane might hold up for a while and act as a temporary solution, but it’s difficult to say how long it will last or whether it’s worth the expense to have trades come in for such a limited repair.
Let me tag @Nailbag to see if he has any thoughts.
Mitchell
