AL_z wrote:
Jules Richardson wrote in
:

On Wed, 21 Jul 2010 16:13:53 +0000, AL_z wrote:

I'm installing a new bathroom in my house. One of the jobs is to tile
the walls adjacent to the bath, as I'm going to install a shower
attachment.

One of the walls seems to be made of thin (8mm or 10mm?)
plasterboard. On that wall, I'll be fixing a shower attachment
holder. Is it OK to stick the tiles directly onto the plasterboard?
Or should I face the plasterboard with say chipboard first, to
increase the rigidity and strength?
That doesn't sound very thick, given that it's a shower wall that
might get bumped by elbows; I'd go with the thickest wall you can get
in there (it's preferable to go with one piece; fixing one thin layer
to another won't be as rigid as just going with one thick layer in the
first place - but I appreciate that you might not want to rip the wall
down :-)

This side of the pond they do a cement backer-board for tiling onto
(often branded as wonderboard)

Thanks - I was looking at 12mm cement board today in our Travis Perkins
store. It's fairly expensive, Agreed, it's probably the most reliable
option as far as staying inflexible and flat, long term, and least likely
to be degraded by dampness. However, I guess it'll be a bit iffy trying to
screw onto it, so I'm thinking of using WBP 18mm ply (exterior grade ply).
Perhaps not quite as reliable long-term, but more screwable-into..

Al




You can most certainly tile straight onto 12mm/15mm plasterboarrd if its
reasonably well studded. The tiles stiffen it up no end, and its the
standard way for builders to do it.

NO preparation needed with one caveat, If your tiles have places water
can collet and you get grout flex and cracking, you will get water
behind. Not good. My way to tackle this is to use silicone on the BARE
PLASTERBOARD wherever there is a possible point of flexure, where it
meets a basin, bath edge or shower tray, and then tile OVER that. So if
water gets behind the silcone will stop it there.

12mm MDF or even 15mm MDF is superb fior tiling: I use it to box in
anything. Or chipboard, but as with plasterboard these too need to be
thought about to prevent water getting to it. All the above swell enough
to blow tiles off if they get wet. Grouted tiles are more than enough
for splashes, but not for puddles. Use silcione behind tiles if there is
a potential nastuy corner.

This has led to the mistaken assumption that you therefore need
waterproof crap behind tiles. This is bull****. You dont. TILES ARE
WATERPROOF and GROUT IS HIGHLY WATER RESISTANT.You need it if you cant
seal reliably and tile and grout properly. Its amateur bodgery and
muddled thinking.