rendering

by **dan007** » Tue Sep 20, 2011 8:07 pm

hi been plastering and rendering a few years lately having a problem with render blowing cracking and sometimes top coat appears weak ie easily marked when ladders leant against them i always soak walls first with water use washed plastering sand 4 sand 1 cement use addmixture everbuild 3 in 1 premium waterproofer plasticiser to slow down setting time then soak the scratch coat then apply top coat with 5 sand 1 cement again with add mix as above then float wall and sponge granted last job was on relatively hot day and sun was on wall all afternoon please advise

by **welsh brickie** » Wed Sep 21, 2011 6:09 am

use a pva solution on the scratchcoat just before 2nd coat and add pva to the final mix.You dont need waterproof in the top coat just plastiser.

by **dan007** » Thu Sep 22, 2011 4:54 pm

thanks was always taught not to use pva with cement though

by **welsh brickie** » Fri Sep 23, 2011 6:21 am

[quote="dan007"]thanks was always taught not to use pva with cement though[/quote]
I have never heard of that,but if you dont want to use it you dont have to,its like adding a resin to the mix

by **dan007** » Sat Sep 24, 2011 6:14 pm

many thanx your a star