I would definately wate. I've seen credit purchases ruin purchases for people before.

Bob,

You probably signed a letter stating you have not received any new credit. If you receive new credit, you are required to disclose it to the lender. With closing so close, just play it safe and wait until you actually close before you buy the carpet.

As I understand current market conditions, banks and mortgage companies are very careful and are running last minute checks prior to closings. If I were you, I'd wait until after the closing before using any credit outside your normal routine. You might want to spend the time checking out the problems with installing carpet in a basement.