I am removing the carpet in my basement. After getting everything off there are holes at the edges where the nails were, would it be a bad idea to fill in the holes with plaster instead of buying a concrete filler? because I have a huge bucket of plaster and would rather not have to go to the store. The edges aren't going to be visible after I put paint over them and put in furniture anyway
Yes a bad idea. Buy a small bag of multipurpose cement.
