europachris wrote:Cap will keep out rain/snow, etc. and help prevent corrosion inside the chimney. Coal ash has sulfur in it. Sulfur + water = sulfuric acid = rot out metal.
Cap can also collect ash, etc. and clog if not maintained, but MUCH worse if burning bituminous. That can clog a cap in a day or two.
Doesnt sound good. So there isnt much you can do just keep an eye on it. I saw this cap listed on another site and it said you cant use it with coal thats why I asked.. I do get some down draft sometimes if it is extremely windy out but im assuming thats normal.