what is the best anti mildew to paint on render on house

Hello you will need to wash the render with a fungicidal solution then once dry you can then apply a good quality Masonary paint.If the render is still extremly chalky after preperation it would be best to apply a stabilising solution before painting.I would use Dulux Trade weathershield products which can be bought from your local dulux trade centre or Brewers decorating centre.As long as you follow the instructions on the tins you cant go wrong. Hope this helps

or sandtex smooth. which is very good.

Also, depending on the mildew ''source'... Find it first, then choose appropriate treatment.

i would say to use a jetwash first to take all the mildew off and clean all the walls then you can use a plilight oil based masonary paint from layland paints