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How to Vent A Water Heater Through Your Roof

A proper vent on your water heater is essential for health and safety in the home. The vent must expel dangerous carbon monoxide in the exhaust to the outside. On top of this concern, you must also ensure that the roof vent does not leak. With a little care, you could successfully learn how to vent a water heater through your roof. A vertical vent pipe from the water heater through the attic and roof will efficiently remove combustion fumes.

Water Heater Vent Installation Tips

Use vent piping that fits the draft hood on the water heater. For example, a 4-inch draft hood connection needs a 4-inch vent pipe. Do not use a reducer to fit it into a 3-inch vent pipe. Double-walled vent pipe pieces are usually built with twist-lock connections. Sheet metal screws will only be needed to connect the initial piece to the draft hood. Sections of single-walled pipe are joined with sheet metal screws. Drive three screws around the diameter of the pipe joint. A water heater vent kit should include pipe sections and the vent roof boot.

How To Vent A Water Heater Through Your Roof Step by Step

  1. Inspect the attic area above the hot water heater for obstructions. You don’t want to cut into a ceiling joist.
  2. If a ceiling joist would be in the way, shift the placement of the water a few inches if that’s possible.
  3. If the water heater is already in place, use vent pipe elbows to shift the vertical pipe over.
  4. Move aside attic insulation above the water heater.
  5. Go to the water heater and measure from the center of the draft hood straight up to the ceiling.
  6. In the attic, measure from the attic floor straight up to the roof.
  7. Use these measurements to buy enough vent pipe to span the distance.
  8. Buy a vent pipe of the correct size for the water heater.
  9. Mark the ceiling directly above the center of the draft hood.
  10. Hang a plumb bob from the mark and confirm that it settles directly over the draft hood.
  11. Center a section of pipe vent over the mark and trace around it.
  12. Cut the ceiling hole with a jigsaw.
  13. Go into the attic and use the plumb bob to find the point on the roof straight up from the ceiling hole.
  14. Trace around a section of the vent pipe to mark your cutting line on the underside of the roof.
  15. Drill a pilot hole through the roof.
  16. Insert the jigsaw blade through the pilot hole and cut out the circle.
  17. Begin connecting your sections of the vent pipe.
  18. Drive sheet metal screws through the joints as necessary or twist-lock the connections.
  19. Slide the final section of the vent pipe through the roof hole.
  20. Go on the roof.
  21. Flip back the shingles and caulk around the pipe.
  22. Slide the roof boot over the vent pipe placing the flange beneath the shingles.

Tools & Materials

  • Safety glasses
  • Measuring tape
  • Plumb bob Weight
  • A Jigsaw tool
  • Power drill
  • Caulking gun
  • Water heater vent kit
  • Ladder

Worried About Cutting a Hole in Your Roof?

You are correct to be cautious before cutting a hole in your roof. The professional roofers at PJ Fitzpatrick know how to cut and fit vents properly. We can ensure that the vent boot is well sealed and able to withstand the elements. Our professional roofing repair team can help with any of your roofing questions or concerns. Call 1-877-246-4354 or contact our roofing team for a quote today.

Need help with this project?

We have trained professionals that can help. Contact us today. 1-877-246-4354

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