How to renovate the wall, including fan ash, and how to choose the material and construction method of oil emulsion paint?

Will the problem you mentioned be so wet in the future? It is suggested to scrape it off first, then brush it once with 108 glue (the kind made by boiling polyvinyl alcohol with water), and then scrape the waterproof putty (or exterior putty) twice. Exterior wall paint is the best latex paint. In this case, you will save a lot of worries.