In article om,
Niall Smart writes:
Thanks for your replies - very useful, I think I will give it a go
myself and save a few hundred euro. I was wondering how to setup
screeds to make it easier - that plumb dot and plaster screed
technique you describe sounds like it will make it fairly
straightforward. The sand/cement render already on the wall is
fairly solid, so I think I can apply the new coat over it. The nice
thing about the Ardex AM100 was that it can be applied thinly, and
sets quickly - apparently you can tile onto it the same day - wouldn't
I have to leave a regular sand and portland cement render 2-4 weeks?

Yes you would, but I'm not familiar with the product you mention.
Check if it requires any type of bonding layer on the existing
render. Mortar has a two-stage set. The first happens within 24
hours at which point it won't move anymore, but will break easily
(or at the micro level, you can brush the surface off with your
hand). The second stage takes about 6 weeks to reach its final
strength, and then you won't be able to brush the surface off with
your hand. For tiling on, you don't need the full 6 weeks, but it
needs to have dried. Most tile adhesives require the surface to be
dry, which usually requires waiting some days depending on the
thickness of the coat, weather, etc.

--
Andrew Gabriel
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