Painting old patched up render - advice please

[MrHfromBath]

Hi, I can't currently afford to replace the render on the two gable ends of my house, so am patching up the few blown bits and will paint the sides (no paint currently). It is pretty old render apart from the patches and newly rendered chimney. The house is rural and was built in 1890 and has a lovely stone front, with brick sides and back.

I am looking for a cream paint, nothing too bright. I have a few questions:

1. What is the best preparation for the walls? I have read about brushing the render with a stiff brush. I have also read about fungal washes and jet washing (it's very high so getting a jet wash up there could be very tough).

2. What is the best paint for this scenario? My main concern is covering the patches as well as possible. My roofer told me about a paint that goes on quite thick for the first coat and smooths out the bumps. I have also read about sandtex, weathershield and johnstones. I have also been told that a rippled effect might hide any bumps better, but might look so good. What advice do you have?

3. Finally, how many coats do you recommend and should the first coat be thinned or just applied straight on?

I would love to get a few testers to see colour and texture, but am keen to get advice first. I've done loads of painting, but never an externally rendered wall. Thanks for your time.

 

[TheDec]

If the render is in good condition not powdery and free from Algae just a stiff brushing down should be fine. You should thin your first coat around 10% followed at least one more coat, this will depend on the overall result. Sandtex Textured paint is about the best.

Dec

 

[MrHfromBath]

Thanks for that dec. However am I not likely to see the patches by just adding paint on top. There are around 10 patches which with the best will in the world will not join perfectly with the additional render. My roofer recommended High-build to put on the smooth out the unevenness. It looks very pricey and I'm not sure how easy it is to apply, but I am keen to avoid clear patches showing through the paint. Thanks again.

 

[TheDec]

Paint is only a coating, whilst Sandtex textured Masonry paint is more than capable of hiding minor imperfections and hairline cracks it I'm afraid cannot work miracles. You will need to blend in those Patched areas to match the existing render before you apply your paint.

Dec