rendering on painted wall?

[joebilge]

If you needed to do a small band of rendering on a wall that was already painted what would be the best way to go about it? There is quite a good depth in the pointing for a key. Would we need to remove all the paint or is there any kind of preparation you could use.
Cheers very much

 

[Fluffster]

What paint is it gloss emulsion?
Render is all about adhering to the surface otherwise it can blow.
Pete

 

[joebilge]

Its exterior masonry paint.

 

[roy c]

Just get a grinder and grind diamond shapes all over it , quite small (about 4") wide then before you scratch it paint either a strong pva mix or pva mixed with cement into a runny slurry all over it , let it go tacky then scratch coat it (4-1 with a drop of w/proofer) then float it with 5-1-1 sand cement and lime (no additives) jobs a good un'. Make sure your grinder goes into the brickwork to make the "key".

 

[joebilge]

cheers very much indeed, I shall try that out today.