In article ,
"Tim Smith" writes:
Hi

Moved house last year and the new place needed loads of plastering done.
Rather than pay a plasterer to do it all, I went on a course.

On the course we were taught using a sand/cement undercoat onto bricks
followed by a skim coat. Most of the plaster at home had to come off becuase
it was all breaking away anyway, so I redid using sand/cement and then a
skim coat.

I recently had a plasterer in to do some ceilings which didnt want to do and
he suggested that bonding coat would have been an alternative.

Was it wrong to use sand/cement or is this just a different way of doing it
? Im sure the sand/cement would be very difficult to remove from the walls
now !

Bonding coat is much easier. You would normally only use sand and
cement to provide a waterproof undercoat (if you add a waterproofer
to the fix). A plasterer is even less likely to use it as he has
to wait 24 hours before doing the finish coat which turns a job
into at least 2 days -- with bonding coat, you can do the finish
coat with 2-3 hours.

You would have learned sand and cement on the course because it
doubles up as training for rendering, and because they actually
use something called 'student mix' which is sand and lime. It
handles like sand and cement, but you can pull it all off after
a couple of days so the classroom doesn't keep getting smaller;-)
It can be recycled by baking it too, but I don't think anyone
bothers with that nowadays. You will find that if you know how
to handle the sand and cement, you should have no trouble using
bonding coat instead -- it just goes off faster.

--
Andrew Gabriel