bump

Hi All, I was viewing a flat today in London (built in the late 90s) and everything went really well. The only issue is the ceiling around the apartment (not just in the bathroom) is filled with tiny small bumps. I was afraid it was mould etc so I climbed up to touch it but it was hard and...

Over time I've noticed this lump forming in just one area of our floor... First I thought it would be a leaking pipe but there's no piping under that part and our boiler hasnt experienced any pressure drops. I believe this concrete floor was laid down like 30 years ago. Any idea what it could...