Good morning.. Old cottage, roughcast walls many coats of paint, whitewash and whatever. The walls are in generally good nick as far as I can ascertain,but scraping at them reveals green algae under the paint. My plan is to pressure wash the walls back to bare ,I have tried a bit and it comes off reasonably well. I have a proper pressure washer, not aDIY job. Query is, when I get back to bare and do any repairs necessary, what is the best procedure for repainting. I would treat the walls with fungicide ,leave it for a day and then rinse off. Should I then just apply two or three coats straight on, or use some type of primer/sealer? There is no sign of dampness inside the cottage, which is obviously good. All advice appreciated. Thanks.
Apply stabilizing solution after fungicidal wash rinse has dried and after manufacturers advised drying time for the stabilizing solution apply at least 2 coats of masonry paint.
I always understood that Stabilising Solution is used to treat Dusty and friable surfaces,but If I pressure wash the walls to remove all dirt, dust,algae and old loose paint, surely it wont be necessary to use S/S. ?Any time I have used it in the past, it caused cissing.
Not always, it can also stabilise and binds the surface & gives you a sound surface ready for the paint. A favourite of mine is Everbuild 406 stabilishing soulution. http://www.everbuild.co.uk/406-Stabilising-Solution
In the past if cissing occurred it would be due to over application of the stabilizing solution causing an adhesion problem.
Thanks fellas, in the past I have used oil based S/S, and had problems with cissing.However the Everbuild stuff appears to be water based which should be OK. I will use it .
Over generous application of stabilizing solution can glaze the surface leading to an adhesion problem be it spirit or water based.
If the surface is sound no need for stabilising just water down first coat by 1:5 water to paint then apply 2 top coats.
I did the job last weekend. After I pressure washed the wall, it was sound and not chalky.I treated it with fungicide and washed off the following day I cut out filled a few hairline cracks with Toupret and then sprayed on 3 coats of Sandtex,first coat diluted 1;10. The finished result is perfect. Thanks for all the advice. Have a good weekend!
Good result, and I hope it lasts. I agreed with the 'stabilising' recommendations as you clearly did have adhesion issues in the past - algae under the paint - so I think that was a good call. But, like you, I have had cissing issues (had to look that up...) which I blamed on the stab sol I'd used, a Wicke's own product. However, I have used Everbuild since then, and can only recommend it - hasn't let me down.
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