I’ve finally managed to carve out time to reinstall the shower in our main bathroom, which developed a leak. On investigation, it turns out this was yet another botched install — plasterboard in the wet zone, tiles dot‑and‑dabbed directly on, and a few other horrors.
The attached photos show the current state. I’ve treated the walls for mould, but the black staining hasn’t shifted with strong bleach/mould treatment, so I suspect it’s soot from an old chimney — the house is 100+ years old.
My plan is to use Abacus Elements backer boards on both shower walls. The main challenge is the rear brick wall:
Previously had two layers of moisture‑resistant plasterboard, with the tiles dot‑and‑dabbed on the outer board — a nightmare! I’m torn between two options now:
Which approach would you recommend for the most solid, long‑term result, or is there a better method?
I plan to include a tileable, waterproof niche on the other wall in the niche cavity shown in the photos. As you can see, it has some gaps internally — would you recommend closing this off internally with marine ply before installing the niche box, to prevent moisture getting into the stud cavity or something else entirely?
Thanks in advance. I’d really appreciate the collective wisdom here before I commit to the final install.
The attached photos show the current state. I’ve treated the walls for mould, but the black staining hasn’t shifted with strong bleach/mould treatment, so I suspect it’s soot from an old chimney — the house is 100+ years old.
My plan is to use Abacus Elements backer boards on both shower walls. The main challenge is the rear brick wall:
- Bricks are crumbly.
- I can’t remove more of the existing plaster/cement — when I try, chunks of brick come away.
- I only have 20 mm total to work with from brick face to final backer board face. The backer board is 12 mm (Abacus also do 6 mm, but I’d prefer 12 mm for stiffness).
- Prep wall – Stiff wire brush to remove loose material.
- Prime – Everbuild 503 SBR.
- Fill hollows – 4:1 sharp sand : cement + SBR mix for deep voids, allowed to cure ~24 hrs.
- Fix boards – Butter the back of the Abacus boards and comb Abacus KST‑Fix adhesive onto the brick with a notched trowel, then press boards into place.
- Mechanical fixing – Once adhesive is cured, add concrete screws and Abacus washers through boards into the brick for belt‑and‑braces fixing.
- Seal joints – Follow Abacus method with sealing tape and waterproof compound.
- Does the above approach seem sound, or is there a better method given the limited fixing depth and crumbly brick?
- Is Everbuild 503 SBR the right primer here, or is there a better option for bonding to dusty, old brick?
- Is Abacus KST‑Fix the right adhesive for this job, or would you recommend something else?
- Any other tips for getting a waterproof, bomb‑proof install on a wall like this?
Previously had two layers of moisture‑resistant plasterboard, with the tiles dot‑and‑dabbed on the outer board — a nightmare! I’m torn between two options now:
- 20 mm Abacus Elements backer board fixed to current studs, making up the extra ~4 mm with tile adhesive.
- 12 mm backer board fixed to studs, but pack it out with shims or add 12 mm battens to the existing studs.
Which approach would you recommend for the most solid, long‑term result, or is there a better method?
I plan to include a tileable, waterproof niche on the other wall in the niche cavity shown in the photos. As you can see, it has some gaps internally — would you recommend closing this off internally with marine ply before installing the niche box, to prevent moisture getting into the stud cavity or something else entirely?
Thanks in advance. I’d really appreciate the collective wisdom here before I commit to the final install.
