How to Install a Fireplace Pipe Through the Roof

Determine the center point of the chimney on the underside of the roof surface using a plumb bob centered over the stove's chimney connection opening. For a wood stove with a rear chimney connection, attach the chimney's 90-degree starter fitting first, then plumb to the fitting's center.

Drill a 3/8-inch pilot hole at the center point marked in Step 1 through the roof, sheathing and roofing material using an electric drill.

Access the roof and locate the pilot hole drilled in Step 2 into the roof surface. Place the chimney's roof flashing approximately centered over the hole and remove sufficient roofing material to allow the flashing base to rest flat on the roof paper's surface and retain it for reuse.

Draw a circle for the cutline of the chimney hole, making the diameter of the hole the diameter of the chimney plus approximately 5 inches, then cut the chimney hole in the roof surface using a jig saw.

Assemble the chimney sections according to the manufacturer's specifications, from the woodstove to the first section that penetrates the roof surface.

Place the chimney roof flashing over the chimney section coming through the roof surface and press the flashing down until it sits flat on the roof surface, making certain the roofing paper is intact beneath it and overlaps the upper edge. Secure the chimney flashing to the roof using 1-inch roofing nails spaced approximately 4 inches apart along the two sides and bottom edges, but do not nail the top through the roofing paper.

Install the chimney pipe counter flashing, also referred to as a "storm collar," around the chimney pipe and over the roof flashing to complete the chimney pipe assembly, according to the manufacturer's specifications.

Run a continuous bead of exterior-grade silicone caulk around the seam where the counter flashing's edge meets the chimney section's surface.