mixing...

[Plasterite]

Re: mixing

Scratch coat must always be stronger than set coat to reduce hadling, cracking and shrinkage and to allow movemnt. Water proof additives must only be added to the first base coat after dubbing out. two coats of PVA to be applied 30:70 to reduce suction. On two coat work, the scratch coat should be 4:1:1 sand / lime / cement, top coat @ 5: 1:1, if Three coat works required 3rd coat 6:1:1, you shouldn’t plaster in frosty weather, but if unavoidable add an air entrained product.

 

[pwi]

Re: mixing

Pva outside tut tut

 

[Plasterite]

Re: mixing

Hi Pwi
Why tut tut, i know its good practice not to seal brick blockwork so it can breath, but we want to make sure our render is there to stay, what would you recomend, regards steve

 

[church]

Re: mixing

no place for pva externally , unless you mean eva or sbr welcome to the forum plasterite btw

 

[Plasterite]

Re: mixing

Hi Church thanks for your input, im familiar with PVA and Styrene Butadiene Copolymer, can you enlighten me to what EVA and BTW are, thanks Steve

 

[church]

Re: mixing

Btw means "by the way" as in welcome to the forum btw Eva is ethylene vinyl acetate basically an exterior pva but it doesn't emulsify in damp conditions.

 

[Chris W]

Re: mixing

;D
i thought it meant 'external vinyl acetate'... :

(actually i'd never heard of it, i just knew there was something called waterproof pva, the stuff i always walked right past in the merchants going 'kin 18 quid a tub!')

 

[Plasterite]

Re: mixing

Hi Church & Chris W
Thanks for your putting me in the picture
I wasn’t aware that pva emulsified in damp conditions I thought once cured it was a solid matter.
It’s never too late to learn

 

[pwi]

Hi plasterrite its a common mistake made a lot of people its one of the great things about this forum you learn somthing new in every post .welcome to the forum