Priming Exterior Wall before painting with Exterior Paint?

I've just finish rendering an outside wall (was breeze blocks) with sharp sand and cement. When it dries fully I want to paint it with brilliant white exterior matt paint. If I put the first coat on I presume its going to sink straight in meaning I will need to paint the wall about 3 times in the end . I was thinking about priming the wall with some diluted PVA before the first coat of exterior paint goes on, what do you reckon?Priming Exterior Wall before painting with Exterior Paint?
Yes, I would say that was essential.


Ideally leaving 48 hours between and try not to do it if rain is forecast.Priming Exterior Wall before painting with Exterior Paint?
If you had just skimmed a room inside then it would be dry in a week. If you had rendered and skimmed inside then it would take 12 -18 months to properly dry out so you would put a non-vinyl emulsion on so you didn't stop the process. On an external wall you can do neither. Non-vinyl paint isn't good enough externally and regular exterior masonry paint will act as a barrier to the water and may push off and blister. Therefore, unless you want to take a chance leave it till the end of the summer to dry out.





There is no primer necessary for masonry. You put three coats of proper exteriour paint on, the first one thinned a little to soak in. You never put PVA or Zsinnser on render prior to painting. You only put stabilising solution if the surface is friable (unstable). As all these things stop the emulsion soaking into your render they are not best painting practices.
Zinsser is too expensive for this job, get all your old emulsion paint that is in 1/4 empty tins in your garage, mix together and water down slightly ,apply to wall to fill pores, great for a primer paint.


Go out and buy Dulux Weathershield paint, there is nothing in the marketplace to beat it for sheer covering power and life expectency, you can expect 10 years minimum
Yes you can ...As a decorator I would also suggest you use a stabiliser too, it will stop the paint drying patchy as sometimes happens on fresh rendering...


Two good coats should be enough as long as you do not overspread the paint...I just did one a few weeks ago and that was the method I used...
use zinsser primer and 3/4 in or 1 in nap. don't skimp on primer but don't get it so heavy that you'll leave roller marks. that and one coat of good paint applied right should do it. you're going with white .
PVA is no good for exterior walls.





When the paint gets wet the layer of PVA will liquify causing early bubbling or splintering of the paint.
for a start ..you rendered it with the wrong mix ..it should have been plastering sand and cement ..now you have a very open mix ..so give it 3 coats with dulux weathersheild ...dont screw it up twice
Block filler/primer? Always use a primer if something is new.