If you have a defunct or dormant fireplace or woodstove in your home, or a derelict chimney from a heating device that is already gone, you can make a bit more space in your home and reduce the chances of leakage in your roof by pulling out the chimney. A metal chimney is much easier to remove than a masonry chimney.
Things You'll Need
10 Screws, 2 inches
Plywood, approximately 10 inch diameter
Roofing nails, 1 1/2 inches
Remove the Chimney
Examine the length of metal chimney from where it comes through the roof to its peak. Somewhere on this length there is probably a metal strap that is tightly wrapped around the perimeter of the pipe. If you can't see it, it is in the attic where the pipe passes through. Pry this strap open using a screwdriver or the claw of a hammer and remove it from the pipe.
Lift the top section of pipe off the section below it. Wiggle them around a bit if they are stuck together and they should come apart.
Remove another section of pipe if it is still protruding above the roof line. If it isn't, you can proceed to fixing the roof, or you can remove the entire chimney all the way down to the basement. Remove all the straps in the same way that you removed the first one, and the sections of pipe will come apart.
Repair the Roof
Slide a board that is longer than the diameter of the hole in your roof through the hole and hold it up against the underside of the hole. Screw the board on by driving screws down through the roof sheathing and into the board.
Measure the diameter of the hole in your roof and cut a disc of plywood to fit it using a jigsaw. Place the piece of plywood on top of the board that you screwed in, and screw the plywood disc to the board.
Separate the lower edge of the shingles that are above the hole from the shingles beneath them, being careful not to tear them.
Put a piece of tar paper over the entire area, sliding it as far as possible under the shingles above and to both sides of the hole. Staple the tar paper down to the roof sheathing.
Install shingles that match the existing roofing by sliding them up under the shingles above the hole and positioning the new shingles so that their bottom edge is even with the bottom edge of the shingles to the left and right. Nail the new shingles down with roofing nails, placing the nails underneath the shingles in the next row above so that the nails are invisible when those shingles are laid flat.
Apply roofing tar to the bottom underside of the new shingles and the shingles in the row above them, and press all the shingles down so that they lay flat.
Insulated metal pipe is quite expensive. You can probably sell your used pipe and get a bit of money out of this job.