Got some walls to tile that have been plastered and painted previously, what is the best way to prepare?
On the new plasterboard i have used some of the Bal acrylic primer and it does say to dilute on old walls , why is this surely it would be better undiluted?

If you can remove the paint then that is the better option...

As for the primer..then if the walls are gypsum based and using cement based adhesive then 2 coats neat...other wise you can dilute to just use as a dust sealer.

Fairy washing up liquid cleans dirty plates and pots, however if you dont dilute it with water it will do nothing except sit on your dirty crockery, its always best to follow the manufacturers instructions that are on the product, they test these things out in order to find out how best they work. Acrylic bond would dry very quickly in its neat state and leave thick drip marks, it would be a more expensive product than it is, dilute it 3-1. You should not tile onto painted surfaces, if its emulsion you scrape it off, if not you will have to score it. What condition is the plaster in, what tiles are you using, size and weight? Plaster has a weight limit, plasterboard is better.

tiles are porcelain 600 x 300 and weigh 4100g each
It is only a relatively small area that is old painted plasterboard and is in good condition.
Are they too heavy? and would new unplastered board be stronger?

Do i need to do 2 coats of primer on the new plasterboard also?

Here is a quote from BAL pdf for APD acrylic primer.

6) Apply undiluted to background/base, except concrete and cement:sand screeds.
In these cases dilute BAL-PRIME APD 1:1 with clean water. Floorboards require two
coats.

http://194.223.92.131/pdf/Technical%..._Prime_APD.pdf


As diamond mentions please do consult the maufacturers guidle lines, not all acrylic primers are the same and also SBR primers are different as well... SBR being a polymer-synthetic primer/additive rather than acrylic, so is ideal water for increasing water permeability in mortar/render mixes and great for slurry coats when mixed with portland cements..and acrylic being more for the prevention of ettrignite failure when applying a cement based adhesive to gypsum substrates....

oops soz waffled a bit there...i think you get the drift...

They are too heavy for plaster, plasterboard is best, someone will post the weight limits soon as i cant remember them without going out to my van for my black book and right now I am building the biggest lego tower in the world with my little princess.

Lego.....used to love it...pics please..

here the weight limits,.. Tiles and Adhesive Weight Per Square Metre - THE TILE SOURCE

Originally Posted by Dave

Lego.....used to love it...pics please..

here the weight limits,.. Tiles and Adhesive Weight Per Square Metre - THE TILE SOURCE

area concerned is end wall of small ensuite around the door so area would be 500mm x 2400 ish up each side of door and along the top.
other area is around window so again not large expanse, does this make any different?

Originally Posted by ukracer

area concerned is end wall of small ensuite around the door so area would be 500mm x 2400 ish up each side of door and along the top.
other area is around window so again not large expanse, does this make any different?

nope, they'll break just as easily when they drop off