How to Install a Chimney Pipe Roof Flashing

With your flue all set up and ready to go, you’ll want to then fit the chimney pipe roof flashing. This is perhaps the most difficult of the stages for fitting a flue; however, this guide will make it a far simpler process.

Make sure you have:

  • A jigsaw
  • Dust mask
  • Gloves
  • Safety goggles
  • Old clothing or overalls
  • Someone else to help you
  • Ladders to get onto your roof
  • A drill or hammer
  • A marker
  • Roof tar sealant
  • Silicone sealant

Step One:

Locate the place where the flue will come through the roof and drill a long screw or hammer a long nail through the roof where the centre is from the inside. NOTE: make sure the diameter of the flue is at least 2” away from any piping and/or roof supports. Centre the chimney pipe roof flashing on the nail and mark the circle of the inside of the flashing on the roof.

Step Two:

Remove the flashing and, using a jigsaw, remove the roof tiling inside the circular marking but keep it aside for re-use. With the hole made, loosen the tiles around the top half of the hole so that the base of the flashing can be fitted underneath them and the flue part fits neatly into the semi-circle.

Step Three:

With the fitting of the flashing tested, remove it and begin applying the roof tar fixing around the bottom of the base of the flashing. Bring the pipe of the flue inside up to the hole you have made in the roof and then ready the flue exit which will be placed inside the flashing. Now place the flashing back in the position you tested it in and press it down on to the roof, waiting for it to set. Nail down the tiling you had loosened when this is done.

Step Four:

Place the flue exit inside the flashing and connect it with the flue underneath. Now take the storm collar that should have come with the flashing and place it around the top of the flashing’s neck so it covers the gap between your flue exit and the flashing. Use the silicone sealant to secure this to the flashing. With this done you’re finished!