It can mean eroded, worn out, or crumbling.
(Basically it's saying that the barn is falling apart because it's so old and destroyed from weather.)
From Eugenes point of view he is tired of Kate nagging him. Hence the sarcasm in the quote “You said yesterday , “I told you a hundred and nine times not to leave your things around the house.” From looking at Blanche’s input we can also tell that Eugene is being sarcastic or “smart” towards Kate by the quote “Don’t be fresh to your mother , Gene!”
