I brought a property a year ago. It has 50ish year old parquet flooring which I've since sanded and oiled (hardwax oil). The parquet seems to have been attached with bitumen. This black stuff is bubbling up at the edges slowly. Does anyone know why this is and what I can do about it? I just glossed a whole load of it and the next day bubbles had already appeared?
Hope you can help.
Hope you can help.