Question: I have a 1920's house which had an open double fireplace. I removed some brick work and now have just an open fireplace. The chimney extends up the wall and into the roof, but falls short of the roof line. I would like to extend this chimney. As I understand it, if the chimney is under 10 feet away from the peak of the roof line I must extend it past the roof line by 2 feet, otherwise it must be 3 feet. I am considering doing this myself. Should I or should I get an expert? Also do I need a cowl or dampers or chimney cap on top? I'm not sure which is best to use or why. Answer: Chimney should be 2 ft higher than anything within 10 feet. Honestly, it does not sound like a DIY job unless you are already quite skilled in masonry work. A cap is optional, although it can help keep rain from coming into the chimney. Depending on chimney and damper design, rain can even drip down into the fireplace and/or rust the damper and frame. Even if it doesn't come this far, it can harm the masonry and cause house odors.