We're in an old apartment built in the 70s and there's a strange fireplace/mantel that doesn't actually work. I can't tell if it's been bricked up or was never functional - but have recently discovered this gap in the top that is filled with heaps of gross black dust.
Is there a good way to patch up the hole? Our place gets quite cold in the winter so I assume this is leaking a lot. It's also quite dusty so I assume this might be a culprit!
Would also love any ideas for how we could use the space a bit better! Is it hard to remove the brick to install something in the space, or plaster over it so it looks better?




