Mapei Shower Waterproofing Kit - observation, and supplier Q

Halfway through a tiling job onto hardibacker tanked with the Mapei Shower Waterproofing kit, we had a change of heart on the tiles and tile pattern.

Cutting a long story short, had to remove tiles after a week, with inevitable damage to hardibacker and tanking. Worryingly, the Mapei tanking peeled off depressingly easy where it was applied over the corner tape. Very low adhesion levels indeed (all applied in strict accord with the instructions). Something you wouldn't ordinarily notice I guess, as the rest of the tile holds on sufficiently strongly so you'd never know, but something I thought I'd mention! You can just peel off the mapegum - doesn't really adhere to the tape at all.

Anyhow, About to make good by replacing 3 Hardibacker boards, and re-tanking where necessary. I need another Mapei waterproofing kit - don't want any weird reactions - anywhere doing this on special? I bought the first batch from Screwfix on special but the price has jumped up by 20%.

Thanks,

Simon

Never worked with the gum....and IMO you don't need it when using hardie boards to w/proof...just tape all joint/corners with fiba tape and run skim off flexy adhesive over joints.....then tile away...


P.s
For waterproofing walls and floors....I always use a membrane,hang like wallpaper,then tile away no need to wait 12-24hrs for tiling..

Understand that tanking is required because Hardi s not impermeable to water - just doesn't deteriorate in its presence, thus a waterproofing layer is essential.

Same as Aquapnel but in domestic use doesn't need tanking.

Just a quick update to this: In cleaning up ready to retile, I was able to peel off the gum in large sheets - adhesion to these boards was not at all strong and I was able to clean up/remove the tanking entirely from the untiled areas with minimal effort until it looks like tanking has never been on it. Interestingly though, where I had tiled and needed to remove the tiles, the hardibacker gave up before the gum, except over the taped joints, when the gum easily separated from the Mapei waterproofing tape. Very minimal adhesion there.

Did you prime it twice waiting on the first coat to dry then apply second coat...also did you wipe the boards with a damp sponge to remove any dirt/dust.....


As previous not a great lover off the paint on stuff ....give the tech boys at hardie a call...

I did - followed instructions to the letter.