Hi
first post on the forums. i will have a few questions i reckon as we go along ,so here goes. I am tiling a bathroom from floor to ceiling. The existing tiles are in good sound condition and i will be giving them a good sugar soap down before i start fixing on top of them. The other surface is plaster board i have put up on one wall . i wasnt to happy with the tiles on there Can i use one adhesive on both (powder or mixed) and would you prime board eg, pva . Also is there any need to pva the tiles with a mix of sand in it to get a key as i have read somewere
thanks

Hello and welcome...


Before we go any further read this>>>>>> http://www.tilersforums.co.uk/tile-a...s-primers.html

ok Dave thanks good advise on the pva issue Any suggestions on the other queries
thanks

take the tiles off and re sheet the wall.

What tiles are you fixing(ceramic/other)

what size are the tiles?

what thickness are they?

ceramic tiles they havnt been bought yet but i am looking at an 8" 12" tile and as thin as they come i reckon Not really sure on that but certainly not "beefy" ones i have done tile on tile before years ago and not had a problem it is what adhesive for both surfaces is right and how to prepare them
thanks

Adhesive wise it will be cheaper to pull the other tiles and plasterboard off and just re-board the lot...

You will need a highly flexible adhesive to tile on to the existong tiles unless they are a matt/non glazed tile.

So once boarded and dry IMO cement based is better but depending on tile size you can use dispersion adhesive on the plasterboard..

thanks for the two suggestions i understand what you are saying about cost in the long run. Just a point if i board out will i just apply straight to the boards with a dispertion adhesive and no primers and would the same stuff be ok to put on ceramic floor tiles that are to be laid on marine ply i will be laying
thanks

NO..just for the walls....you will need a suitable floor adhesive for the tiling onto the ply floor..

What substrate is under the ply and what tiles you using.? and how thick is the ply..

Originally Posted by norbellini

thanks for the two suggestions i understand what you are saying about cost in the long run. Just a point if i board out will i just apply straight to the boards with a dispertion adhesive and no primers and would the same stuff be ok to put on ceramic floor tiles that are to be laid on marine ply i will be laying
thanks

as Dave and Brian suggested, would start from scratch, ie replasterboard and not tile on tile

i was looking at three eighths ply screwed at 6 inches on floorboards, bog standard Bq type 12inch ceramic floor tiles and again would you put straight down onto ply and not prime
thanks

Not thick enough ply........why not try hardi backer....?

thanks for the advise i removed all the tiles down to brick and i have dot and dabbed plasterboard . So could you tell me what i should use on the plasterboard to stick 10 by12 wall tiles standard thickness
thanks

Use a spf for the walls and give the plasterboard a primer eg bal apd

Originally Posted by whitebeam

Use a spf for the walls and give the plasterboard a primer eg bal apd

I would agree with that, though you won't necessarily need a fast setting SPF, otherwise you could be chucking loads away unless you are quick.

If you are tiling behind or around a shower area (cubicle or shower over bath) you will need tanking membrane, especially if this area has been plasterboarded. Wetdecs (one of our sponsers) can advise here.

I'm glad you've removed the old tiles and started from scratch. Too many people are hoodwinked by certain products that encourage this approach. They don't realise the weight issues with this method. Unskimmed plasterboard has a limit of 32kg per square metre and two layers of tiles can exceed this quite easily. Not to mention the increased potential for adhesive failure.