1st Job: Shower tiling? is my plumber right?

[Realstokebloke]

Hi, newbie, first big job, you know the drill...

I have extended a small, x3 sided sq. shower into a rectangular tray, so have taken out & replaced one (stud) walls & replaced the backing completely.

The facing / back wall needed to be ripped out to halfway on the line of a noggin (approx mtr high) & replaced below that.

So the top of that wall & the whole of the other side wall is the 'old' plasterboard with the old adhesive ridges in / on it. It does have a new panel of plaster board over a new mixing valve now seated behind tho'.

This is me to the plumber. Ref the 'new' backing board, which is just straight plasterboard:

"Will that be OK ? Don't i need that Aquapanel or similar?

"No, be fine".

Ref the 'old' plasterboard with the ridges:

"Will that be OK to tile over? & do i need to get rid of the ridges (it looks like old tub adhesive used on what were smaller tiles).

"No, be fine, just have a thick bed."

"Do i need to seal it with PVA or similar?"

"No be fine, straight on."

Now, by chance & 'cos i don't want to get it wrong as the new tiles, shower & screen all cost a bomb, i thought i'd check out that 'advice'.

So B4 anyone shouts "no PVA", i now understand that, thnx.

And for info, the adhesive i have used for the floor is Unibond Rapid set ultraflex (which is their best one they tell me) & was going to use this again on the walls.

I also understand that if i keep the 'new' plasterboard, i can seal it with an acrylic primer (like BAL'sAPD is it?)

I am also using 330 x 330 tiles, so know / think i need a cement based adhesive for the size & hence know / think i need an acrylic so it doesn't break down the plasterboard.

I then delved deeper and see you can tank it. As i understand it, this primes with an acrylic (APD-type) then uses a mesh to seal the base & sides & then has a thick gunky stuff over to waterproof it?

So (& if this is correct so far), my options ref the new stuff are to:

remove it & replace with Aquapanel or similar? (not ideal, as it's all "in" & snug & square & straight & will cost to replace)

to simply acrylic prime the new stuff and press on.

to tank it to be sure?

My options ref the 'old' stuff:

replace (aquapanel)

or will an acrylic seal-in the old adhesive to stop a reaction with the new? (or do i have to get it all off first - & if so, how? - so that it's flat al well (there are some small ridges in it nothing major & as the plumberman said, it will even out with a decent bed.)

Or will tanking over that seal it all it & "belt & braces" it as it were?

To me, it sounds like a tank kit - any particular one? The BAL looks OK but has only 5M of tape - the Mappei one OK?

I'm also boxing in a waste pipe run but can only fit in really thin ply (WPB). Would i be as well to use a gun adhesive to stick these as the mix adhesive above?

I hope i've averted a car-crash (if i did as 'advised') and be very grateful for your thoughts guys, cheers and sorry, it ended up like a play script at the top !

Advice too on telling the plumber gently, he's no tiler (he's a decent guy & an OK plumber so far).

[GirlRacerRed]

well you've come to the right place to check out what you've been told so far. Thanks for understanding the situation about PVA. And you're right, your plumber is a plumber and not a tiler. Wait for the members of this forum to read your post and stick their views down and then you'll have advice from tilers.

and we hope you enjoy the rest of the forum.

[Realstokebloke]

Thanks GRR (nice acronym too).

Not a good day so far on this but while i'm on, i better 'fess up on the rest - the floor.

I had previous tiles straight onto green chipboard with a tub flexi (no ply) no nothing infact & used an ordinary grout with a flexi additive. &, against all odds (i now know) it was solid & uncracked.

this time i bought (what i thought) to be a decent cement adhesive (but now, not so sure) Unibond Rapid set ultraflex & the best Mapei flexi coloured grout - forgot the exact name - (both as mixes) thinking i'd get a better result.

This time, i 'ply-wooded' it & did a 5:1 PVA seal over as per the bag instructions on the unibond.

But...two of my tiles popped straight off. i phoned unibond who told me the ply i used was too thin (6mm vs 15mm as per BS Regs) but...that should affect it too much & to be fair got me to send back a sample for testing (still at the lab) & gave me a credit for a new bag of same.

I cleaned it all off & them down again but the still move a little & so have to come up.

I also contacted mapei about the grout (cracking accordingly) & they scoffed at the 6mm & laughed at the use of PVA.

But, as per above, i really, really, don't want to take the floor up (the tray, toilet are in & down as above - & there would be a divorce) to start putting 15mm + down + more new tiles.

Any ideas?

Obviously, i'd scrape any PVA off & add more screws into the chip / joists below for added stability.

But,how 'far' back will i have to go?

Can i re-stick them with a better adhesive?

Can i add a dollop of flexi additive to the grout to help?

Also, where it's stuck, the grout has really 'stuck' - any best ideas for grout removal where it's cracking?

And any better grout instead? Mapei even said silicone ?? : 0

[macten]

I personally would replace the lot with aquapanel as it would be quicker and simpler - no need to prime, no need to tank and will be perfectly flat for tiling.

If for some reason you don't go down that route then my advice would be to remove as much as the old adhesive as possible using a scraper with a blade on. If the old addy was tubbed gear then dampening it will make the job easier.
Prime all plasterboards old and new and tank wet area of shower as per manufacturers instructions. I use mapeis or webers tanking system and 5m of tape is plenty as it is very wide and you can cut this lengthways to give 10m.

As for the boxing in I would use a 6mm cement board and tile in the usual way.

Hope that helps

[macten]

With regards to the floor I'm afraid 6mm ply is totally inadequate so the lot needs to come up I'm afraid.

Never ever heard anyone say anything good about unibond tile addies/grouts so steer clear in future
and use a quality product.

[CJ CERAMICS]

As with macten on this one, replace the boards with aqua and ditch the unbond (sorry unibond) addy and use mapei keraquick if you are quick or keraflex if not instead.

chris

[Realstokebloke]

Cheers fellas.

I can live (albeit am hacked off) with replacing the wall backing boards and buying more & using ano adhesive (& having a good go at unibond for recommending PVA while i'm at it) or tanking it with a kit. But...the thought of ripping the floor out sends a shiver down my spine as it means the lot has to come out again obviously...eeek.

The thing i don't get is that w/out any ply over it, the floor was solid before & stood the same tile (weight/ size) with inferior grout & adhesive.

but if it has to be done now is the time to do it before going any further i guess.

Any other suggestions for the floor remedial from the pro's out there please to re-stick / grout the affected areas?

Cheers.

[tilerjason]

replace it, the guys are right, as above, piece of mine and a pro job, your plumber is a plumber not a tiler, id call a qualified tiler and ask for there advice, the advice will be free

[Realstokebloke]

replace it, the guys are right, as above, piece of mine and a pro job, your plumber is a plumber not a tiler, id call a qualified tiler and ask for there advice, the advice will be free

Cheers Jason - you mean the floor (hope not) or the board on the walls?

[tilerjason]

also could ask for references off your plumber, with regards to tiling and pop round to previous jobs and see how hes done, this should give you some idea of what hes going to be like, also research him on the web

[Realstokebloke]

also could ask for references off your plumber, with regards to tiling and pop round to previous jobs and see how hes done, this should give you some idea of what hes going to be like, also research him on the web

Mate, you might get a call then - despite the u. name, not so far away from you - kirkham in fact !

[Realstokebloke]

OK - if i go the Aquapanel route as opposed to tanking it, can you get a 9.5 / 10mm equivalent to the standard plasterboard thickness that's up now plse anyone know?

[macten]

yes you can mate

[Realstokebloke]

Cheers macten -I'll google it in the meantime but all my tilers & builders merchants say a 12.5 is the min.

Saw your note on the other thread too, thnx & i guess you're right, it's not what i wanted to hear about the floor.

[Realstokebloke]

Thanks too GRR - saw your note on the other thread & acknowledging it.

[macten]

Have a look at the marmox board for 10mm