Painting/ new render

[pablopatito]

I had an extension built which was rendered. The plasterer roughed up the smooth render to try and make it textured like the rest of the house (not very successfully, but that's by the by).

The smooth render is fine. But the roughed up render is what I'd describe as chalky. I can brush off loose render with my fingers.

This is what it looks like: http://imgur.com/a/zZy0E

I now want to paint. Should I
a) Apply Sandtex Masonry Stabilising Solution, then paint.
b) Remove loose/flakey/chalky render with a brush and/or power washer, then paint.
c) Both of the above
d) Something else

I've heard that you shouldn't apply stabilising solution to new render, but I'm not sure why. I have to do something about the chalky render before painting, don't I? It's been a year since the render was applied, so I guess it's not technically "new" anymore, it's just "unpainted".

Thanks.

 

[ic1927]

Go over it with a sweeping brush to remove the loose chalky stuff and then give it a coat of stabilizing primer, use the solvent based stuff. When fully dried you're ready to go with the masonry paint.