Can anyone tell me what this is? It is time to re-paint my house, and what looks to be over the brick, near the base, is some sort of plaster-like skirting (sorry, I know I sound like an idiot!). The thing is, I have no idea if it will crumble when I start to scrape, and how I can re-cast it. Advice appreciated.

Too late to revise this with a more catchy title, so I’ll just have to bump.

*BUMP*

Looks like just sand and cement. Scrape/ knock it off to where its solid and patch it up with more sand and cement then paint it. Job jobbied

Often, when the base of walls are painted black like that, it’s done using a bituminous paint, used for waterproofing up to dpc level.

If the substrate forming the plinth is quite porous, you will most likely need to maintain this waterproofing in order to prevent water from getting in and damaging the structure. However, looking at the photos, it looks like there are engineering bricks behind the finish, so the black paint may just be decorative.

It could be that the substrate you see on the corner is a cement-based render used to form the sloping top of the plinth. You would still need to maintain this slope to prevent water from sitting on top of the plinth and potentially damaging the brickwork.

It’s a happy day when someone can work “substrate” and “plinth” into the same post on a cycling forum.

Now I just need to track down Mariella Frostrup to read it back to me.

Don’t forget “porous”….

Happy to be of service