Hi and Help. Non-stick skimmed bathroom walls

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New boy here. In the later stages of a big refurb and extension project which will be my house! My Builder has a few bits left, but tiling and deco is down to me. Difficult with a full time job. Keen and careful, but new to tiling. Been on a 1 week tiling course as an intro, and have good basic tools. Very grateful for any help from the experienced please!

Working on tiling 2 bathrooms and a cloakroom, so I can get them fitted. Total 30m2 tiles for 2 floors, walls, boxing, traps, mosaics, showerbath recess, walk in shower walls (whose idea was this??). So no pressure. Already laid both floors 330 x 330 porcelains with Bal Rapidset flexi over ply on chipboard floors (not grouted yet) plus 50 x 50 mosaics onto ply boxing using Ardex D30 in 1 bathroom for inset basin and back to wall WC, with traps and 330 for tops. Looks smashing.

Problem is with showerbath recess and walk in shower recess walls, which are skimmed over either plasterboard stud or plastered block (4 months dry). Using a combination of same porcelain 330 square tiles and 25 x 25 mosaic on sheets. Was sold Ardex D-30 adhesive supposed to work on plaster, unprimed. I cleaned down well first but low areas I shallow-filled with D30 just cracked and fell off when dry. Then I well wire brushed whole test area and filled - same prob. So then I primed wall with Ardex Ardion 51. D30 sticks well to it, but running a scraper under when dry, it comes off easily with primer. Not confident it will hold a tile weight, let alone a wall!

Due to mix of wall types and cut/plumbed in bath and tray, don't want to rip walls out and replace with tile backer, but is there likely something odd in my plaster? Should I tank it and will tanking stick? Or is it the addy? Should I be using a cement based powder like the floor adhesive I was using? Am I going mad???

Cheers,

[Dave]

Hi there...that gear the walls are skimmed in is as porous as hell, prime the walls with a watered solution give it 3 or 4 coats to cut down on its moisture sucking properties,might need more coats...then tile with bal single part flexi adhesive this is slow setting so will give you plenty of time to play with the tiles and lasts in the bucket for ages and sets on the wall in about 16hrs..this should work for your project no probs and grout with flexi grout with those porcelain tiles...........dave..

[Fred]

D30 I use all the time on porcelain. The problem is using it as a filler, it will not work that way, as it is bucket gear, it will only dry at 3mm thick. You were correct to dub up the plastered wall. BUT, Ardex D30 is, like it's sister D20, self-priming.

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Brilliant advice, thanks Dave. I suspected the skim was somehow the weak link, as the D30 has a lot of grab, but didn't think of coating with primer more than once. Thought I would have to hack the skim off or rebuild the room!

And thanks for the steer on the adhesive guys. So I will retire D30 from this job. (It has been emotional!) Once primed, is it OK to build up low spots with the BAL SPF? Up to 6mm to build up in one area.

Then would you recommend the Ardex WPC or BAL WP1 tanking kit? I need to do a 1700 recess walk in, and 2 sides over a 1700 showerbath.

Cheers,

[wayne]

i would use the ardex mate. its more expensive but brilliant to use

[Dave]

either tanking kit will be fine..any uneven areas to build up just back butter the tile so as to get a solid fix in these points as well..........dave..

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Will do. Many thanks all.
Up early to buy some more primer then...
Tony