I bought a house which had double glazing fitted before we moved in. I didn't notice when we looked at the house but there is a gap between the window sill and the window. I don't know what it's been filled with but it looks like plaster. (see attached). Mould is starting to show through and it's crumbling because of the damp. It looks awful. I want to dig out all the older 'plaster' and replace it but I don't know what to replace it with. Whatever is used I want to paint it to make the join look as seamless as possible. Anyone have any ideas what to use? Thanks in advance.
