What kind of brick yuck is this?
Hard to tell. Could be mould, could be efflorescence, could be something else. Either way looks like it could be damp related and I’d be a bit concerned about that joist
@Pantsmaster started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
What kind of brick yuck is this?