I'm not going to fix my friends floor
Why don't you want to help your friend?
I don't want to work for free, he should fix the floor
Helping out a friend in need is an admirable thing, however it's understandable that you don't want to work for free. Consider the price of your friendship and whether your friendship is worth being of service to your friend for a short time.
It's not like I got nothing else to do. Money doesn't grow on trees, and I have to put in my effort elsewhere.
I can understand why you can't put in the effort to fix a floor without being compensated.  If you let your friend know that you are in a tough position financially, he might be willing to pay you for your time and wouldn't consider it an insult.  You could also simply recommend a contractor to your friend, and say that you are too busy.