External rendering additives

[Jkb]

hi,

I am planning on rendering an extension wall but I first have to scrape off the old stuff, which should not be a problem as it’s quite dry and flakes off just by rubbing it with your hand. I plan on mixing my own plastering sand and cement. I have 2 questions:

1. When I scrape down to the brickwork, is there anything I should be treating the brickwork with before I render, bonding, waterproofing solution etc....

2. When I prepare my rendering mix, is there any other additives I should be adding before mixing?

Thanks in advance

 

[Alastairreid]

Use an sbr slurry to prime the wall.
Waterproofer in scratchcoat and plasticiser in your finishing coat.

 

[Jkb]

Hi

Thanks........ for the hard of thinking (me) what’s an sbr slurry and what quantities should I apply?

Thanks in advance

 

[Jkb]

It’s ok, I just googled it......duh, why didn’t I think of that.....cheers

 

[roughcaster]

Don't even think about it in freezing conditions. External rendering, roughcasting etc at this time of year is not really recomended, and also, cover your sand up.

 

[Jkb]

All good.... I plan to do the job spring next year.

Cheers

 

[roughcaster]

The best way Jkb.