Help !.... We have taken up some old old parquet flooring which has left bitchumen on the concrete floor..... My husband had used ...Acrilic floor primer , instant contact adhesive and then high performance floor leveller. We now have a smooth floor to relay a beautiful floor...BUT.... we now have a rotten egg smell which shows no sign of going (four days)...we still have one more section of hall to do , Anyone any ideas as to why this has happenned and if it will go. Double Help!!