Rendering Painted Bessa Brick

No replies as yet, so maybe this will help. I have done this before with good results.

Firstly, what condition is the paint? If its bad - cracked or peeling off, then your gonna have to strip most of it - sorry.

If its OK then you need to get a comb hammer and speckle the surface, get thru the paint to the cement at least once every 75 mm. Your wall should have these craters all over, with no more than patches of original paint between the chips. Then wash all over with caustic soda or some sort of soap, depending on your paint. Caustic will dissolve enamel type paints and you dont want this happening, so make it fairly weak. What you're doing is removing any grease so the render will stick - not trying to remove paint.

When dry, paint the wall with a water solution of one of the cement ad mixes, ie Bondcrete - any Bunnings has shelves of these admixes. This provides a good. sticky base for the render.

When dry, mix your render and use more Bondcrete or whatever in render mix - instructions are usually on the can. This will stick to almost anything and the Bondcrete makes the render flow or 'buttery'. It also serves to waterproof and make subsequent painting easier.

This is probably not the correct approach according to the text books. I suspect they would have you strip your wall. But....it works.

If the paint is really rooted and you dont want to tediously strip back, you can always line with thin fibro and render over that - still using the additive as above.

Good luck

Bodgy
Even fools are right sometimes - WSC