PVA admix in plaster scratch-coat/undercoat?

tomfrh

Well-known member
Jan 30, 2018
380
Australia
#1
We'll be replastering our pool at some stage. Some of the contractors I've spoken to mention using PVA admix as bonding admix agent in the sand/cement undercoat/scratchcoat, beneath the final pebble plaster. (Not sure if they add PVA to the final coat too).

Here is an example product: Cemstik®

However, looking at these products they say NOT to be used in permanently immersed applications?

Anyone have any advice here?
 
OP
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tomfrh

Well-known member
Jan 30, 2018
380
Australia
#3
Yeah I've been investigating that. I may order some (we're in Australia).

But even so, people seem to use these PVA admixes as part of their pebble system. I'm trying to understand how it can be used when manufacturers say not to use in immersed applications.
 
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tomfrh

Well-known member
Jan 30, 2018
380
Australia
#5
I did some tests with the PVA bondcrete admix, and compared to waterproof latex admix. They both stuck very well compared to plain water, both initially, and after a week of immersion.