When I moved into my house I had the floors sanded and polyurethaned. It's now 8 years later and the PU seems to have pretty much vanished. I understand that they should have done 4 layers or so but they only did 2. Then again, I didn't pay them very much since I didn't know any better.
Now the question is, can I just lop some more on top or does it have to be removed first? How long before I can walk on it?