Thought that I would try to get some advice.........My 5yr old brick chiminy tends to leak (drip) rain water past the flue into the firebox only during a heavy rain such as today (Earnesto). I suspect that it may be coming thru the top parging since there appears to be some hairline cracks in the cement. What do you think/recommend ???...is there a "rubberized" type coating that I can seal it with?? What about the rest of the chiminy.......what's the best way to waterproof the brick???..I do have "rain caps" installed...thanks