I want to tile the bathroom. It was originally painted with a vynal
emulsion of some kind. I notice that it seems a little fragile in some
places and comes of without too much sanding. What is the best
approach, strip it all?
It is laid directly on the plaster and if as I fear it will have to be
completely removed what is the best option?
I'd have the loose stuff off and dowse the rest with SBR (or an equivalent
tile primer) - that generally is pretty good at stabilising the surface and
the penetration is better than PVA - and it's waterproof. BAL recommend that
approach for new plaster - so it is compatible with tiling.
Thank you. My only problem is identifying what is "loose". Nothing is
obviously lifting. I was planning on using PVA to seal the plaster
incidentally but will certainly look into this SBR.
So far I have tried a combination of sanding and scraping using an
Aldi palm sander. This removes the paint extreemely slowly. I have
tried a chemical paint remover and oddly enough in small quantities it
actually improves the paint / plaster bond to a remarkable degree. [I
am loath to paint the entire wall with with it though as it probably
has drawbacks as a bonding agent]. Used in standard bubble and scrape
quantities, it is fine, but far too expensive for an entire room.
I didn't think chemical strippers worked on water based paints, and
was a little dubious when I read the label [Some blue gel type stuff].
It works though but in exactly the same way as Nitromoors. i.e very
effective, but dashed expensive if you want to keep the physical
labour to a minimum.
I think I'll go for a bigger sander. Screwfix advertise an Erbaur or
similar that takes 1/3 sheets, and the correct sanding sheets are
available, unlike the Aldi device which seems to require some kind of
sheet that is not generally available within this solar system.
I suppose this SBR doesn't penetrate through to the plaster/ paint
interface? I have assumed anything laid on top of the paint [ Which
if it is still on the wall is of an uncertain bond strength] would not
penetrate and reinforce the overall bond. Obviously my blue gel paint
remover must penetrate to the bond and indeed reinforce it, so would
you think that this SBR might do the same?
Running over with a steel (regular) wire brush will probably show you - also
an advantage as it will score the paint and give the adhesive some extra
I think the wire brush stands more chance - for tiling, a roughed up (even
badly) surface is a good thing (TM).
SBR has very good penetrating powers if the surface is not waterproof. IIRC
the BAL instructions were to dilute it 1:1 with water which makes it
thinner. You need to saturate the surface in one go as it cures fairly
quickly and then becomes waterproof limiting the penetration of any further
The one thing it does not do is gap fill - so it won't help paint that is
loose with a gap behind (even a tiny gap). But if the paint is stuck on,
even if it - or the surface of the plaster underneath - is weak, it should
make it most of the way through the skim coat of plaster and it will be
noticebly more solid when dried. If any of the surface was fiable, it won't
be afterwards. It is unlikely to help if the skim coat os loose though - you
should tap the wall and sound it out and deal with any serious bits in the
One warning though - if spilt on any good finishes, eg floor tiles, bath,
etc, wipe up immediately with plenty of water and a cloth - I have still got
a layer of SBR on my stainless bowl I use for mixing various liquids and
even wire wool won't shift it except in conjunction with white spirit.
It's difficult to guarantee success without seeing your wall, but if you do
a test area, leave a day, then take a scraper and a wire brish to it it
should be obvious if it has had the desired effect. But based on what you've
said and the relative amount of work to try to strip the paint or knock the
skim off and replaster, it would be the first thing I'd try.
Actually this paint seems fairly waterproof. I tried
spraying a mist from a Hozelock bottle but it had little effect
I have tried a wire brush ( a cup attatchment for my drill), it seems
to effect a slight improvement in some patches. If I turn the drill on
I get grooves.
The surface of the paint is quite resillient, the only weak bit is the
bond between plaster and paint.
My current plan thanks in part to this NG is a matrix of steel blades
to groove the paint, followed by a good scrubbing with a Screwfix
sander [if in stock].
Come to think of it I'll pick up a wire brush tomorrow, maybe a wire
cup attachment isn't the best for scrubbing walls.
On Sat, 02 Apr 2011 19:43:18 +0100, The Natural Philosopher
Thanks for the reply.
None of the paint shows ay visible sign of lifting, it was only when I
sanded away some grout on a sink splashback that I realised there may
be a problem.
Using a scraper there are areas where I can easily leave a few square
centimeters clean of paint. Other parts of the walls can be difficult
to clear. I do not know how much force is needed to remove the paint
until it is actually off. There is always the thought that the
combination of sanding and scraping that I am using to "test" the
adhesion would maybe loosen the bond on a good paint job?
I did try sticking masking tape to the wall and peeling it away, over
half a meter a couple of 2cm^2 patches came away. Masking tape is
approximately 5cm width.
I was thinking of a bigger sander. I did give a chemical stripper a
try but unless used in extreemely liberal amounts it seemed to
increase the bonding to the plaster as the paint was no longer as
As you are probably aware my practical experience of this type of work
is virtually zero, so I would welcome any suggestion that would help
me avoid spending a week or so trying to remove the paint using my
I found, by accident, that brushed-on meths softens emulsion to allow it
to be scraped. I've used it to remove old paint for tiling. Not recently
so maybe there are chemical changes in emulsion, but perhaps worth an
Always one to avoid the unpleasantness of physical labour, I have
given it a try. There was no discernable effect on the paint layer.
Thank you for the information though, it may be of value in a future
On Sat, 02 Apr 2011 18:45:23 +0100, H. Neary wrote:
I think I'd screw 1/4" cement board onto everything and then tile onto
that - it's more expensive to do it that way, but it'll give you a good
secure base that'll last even if moisture does ever manage to penetrate
between the tiles.
Plasterboard (aka drywall this side of the Pond) is really cheap over
here - I'm not sure about in the UK, though. Tearing down what was there
and putting up new boards would certainly be a possibility here, anyway.
Now listen, I'm gonna tell you a story...
Our last house was bought when it was about 3 years old. One day we
heard a loud bang, and a noise like plates breaking. Couldn't track it
down. Until the kid's bathtime.
It turned out that the bathroom fitters had taken a shortcut. Worked
out where the edge of the tiles was going to be, painted the walls, then
tiled over it. The emulsion went over maybe the last foot of the wall
under the tiles. (this was of course builder's thin magnolia)
The emulsion made a weak layer in the tiles, and the whole top row had
come away. One landed on its corner, and punctured the bath. We called
the builders, and they replaced the bath (not without some cursing, as
it turned out the taps on the new one were in a slightly different
place) and replaced the tiles.
Six months later...
... I noticed that the tiles were coming away. So I carefully (_very_
carefully!) removed the top two rows of tiles, cursed the paint
underneath, scored the plaster heavily and refitted the tiles.
AFAIK it's been fine since. We were only there another 5 years or so,
and it didn't move.
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