The do it yourself resource for homeowners from home improvement professionals.

How to Replace a Chimney Cap

Acquiring the skill to install a chimney cap requires basic DIY proficiency. Nonetheless, this task should exclusively be undertaken by individuals well-versed in safe roof work practices. Ascend to your roof using an extension ladder that extends a minimum of 3 feet beyond the eave. It’s essential to don nonskid footwear and employ a safety harness, particularly on steep roofs.

Important Note: Climbing onto the roof carries inherent risks and is not recommended if you are not 100% comfortable working on a roof. If you prefer to avoid this task, consider seeking assistance from PJ Fitzpatrick for professional chimney cap replacement or installation services.

Guidelines for Installing a New Chimney Cap

Single-Flue Chimney Cap Replacement

  1. Securely position the ladder on stable ground and ascend to the roof.
  2. If using a roof harness, attach it.
  3. Determine the dimensions of the chimney flue, which constitutes the clay or metal tube projecting upward from the chimney structure.
  4. Record the length and width of the flue.
  5. For circular flues, measure the diameter by wrapping a measuring tape around the flue’s circumference.
  6. Input the circumference into an online circle calculator to ascertain the diameter.
  7. Procure a chimney cap that fits the flue, preferably a galvanized steel cap.
  8. Return to the roof and lower the cap onto the flue.
  9. Ensure the cap is positioned at least 6 inches from the top of the flue to facilitate proper release of exhaust fumes.
  10. Use a screwdriver to affix the included self-tapping screws through the cap’s rim holes into the flue.
  11. Tighten the screws until the chimney cap is securely fastened. Some caps might have a clamp for tightening around the flue as an alternative.

Multi-flue Chimney Cap Replacement

  1. Ascend to the roof safely and measure the flues collectively.
  2. Determine the width, length, and height necessary to cover all flues while leaving 6 inches above the tallest flue.
  3. Measure the chimney crown’s width and length encompassing the flues.
  4. Clean the crown thoroughly using a stiff-bristle brush.
  5. Procure a chimney cap that aligns with your specified dimensions.
  6. Mount the roof and place the cap over the flues onto the crown.
  7. Equip a power drill with a masonry bit slightly smaller (1/8 inch) than the installation screws.
  8. Drill pilot holes into the crown through the cap’s designated holes.
  9. Temporarily remove the cap and apply a bead of caulk along the crown’s edges.
  10. Re-position the chimney cap over the caulk and insert installation screws into the pilot holes, securing them with a screwdriver.

Tools & Materials

  • Measuring tape
  • Power drill
  • Stiff-bristle brush
  • Masonry bit
  • Caulking gun
  • Screwdriver

Contact the Chimney Cap Pros at PJ Fitzpatrick

PJ Fitzpatrick’s professionals can help ensure that your home is protected from water and other potential damage, regardless of the size or shape of your roof. If you suspect a leak coming from your chimney, our professionals can inspect your chimneys, vent pipes, and other roof openings to ensure they are properly sealed from the elements. Contact us today to discuss your chimney cap replacement needs.

Need help with this project?

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

Get Free Estimate