search  current discussion  categories  forms - tiles 

tile mural project and "tar goo"

updated tue 3 apr 01


Janet Kaiser on sun 1 apr 01

Although I am taking time out from Clay Art just now, I
was thinking about this "tar goo" and must advise
extreme caution!! No, nothing toxic or anything, but I
smell a rat...

It could be tar or it could be a rubberised or plastic
vinyl or polymer-based material which was painted on.
Either way, I suspect it was put on to keep moisture
out of the wall. It is not cheap and difficult to
apply, so no one would just put it on for the hell of
it or as decoration.

That means a porous wall? Even if you take the black
stuff off, you may have a poor wall surface to stick
tiles onto. Depends how much the render had
deteriorated before the waterproofing was applied, but
it may not be up to any additional weight baring.

No good asking "the school" in this sort of scenario.
You need to talk to the boss of building maintenance to
find out what exactly you are dealing with. That black
could have been a big cover-up and if your tile mural
is being looked upon as a visual improvement or even a
"luxury cover-up" job, it is in your own interest to
find out before you hit trouble.

If it was my project, I would point out I am a
potter/ceramic artist and not a qualified builder. You
could say that you are only repaired to work on a
clean, dry and completely SOUND surface, where all the
ground work has to be done by a qualified and reputable

My caution springs from second hand experience of a
similar situation. The artist was assured the base was
fine, but when the tiles started falling off, they were
blamed for poor workmanship and had to re-do the whole
project at their own cost.

Wales is the capital of "cover up" jobs. Those "quick
cure" adverts get a wonderful response here and there
are shelves full of those products in the DIY stores.
Plywood must have been invented especially for the
Welsh market. Everyone who buys older property finds
panels covering wet walls inside and yes, that black
goo under wallpaper! It is manufactured for outside -
the area where splash-up from the ground increases
moisture levels - but it turns up in all sorts of
situations. It is a lot cheaper than pointing bricks /
stones or rendering the walls. Another cover-up product
is "Airtex" which is swirled onto plaster ceilings
which are badly cracked.

So my message is: if there is ANY reason to think that
a cover-up has taken place, be prepared for a lot of
trouble. Do not take responsibility for the structure /
wall / ground / surface, only your own art work.

Janet Kaiser
The Chapel of Art . Capel Celfyddyd
Criccieth LL52 0EA, GB-Wales Tel: (01766) 523570