Good way to seal top of chimney that is temporary?
My top section is only 15x23 inches. I want to seal it till we can have it looked at or I fix it myself. There are cracks all through the inside of it and i'm told the gas can get in cracks and explode. So I just want to put some kind of metal plate over it that is designed for it if one exists. About 6 bricks on top are loose but I will fix that with some fresh mortar.