Installing a metal roof around a chimney can seem like a challenging task, but with the right tools, materials, and careful preparation, you can achieve a secure, waterproof, and durable installation. This process involves precise measurements, proper sealing techniques, and the use of high-quality materials such as metal flashing, aluminum, and galvanized steel to ensure the roof is resistant to water infiltration, snow, and ice buildup. In this guide, you’ll learn step-by-step how to prepare the area, cut and install flashing pieces, lay roof panels, and seal every joint for a long-lasting, leak-proof roofing system. By following these methods, you’ll gain practical insights and techniques for a smooth installation process and a reliable metal roof around your chimney.
Table of Contents
Tools and Materials You Will Need
| Tools and Materials | Purpose/Work |
|---|---|
| Safety goggles, gloves | Protecting eyes and hands during cutting, fastening, and sealing tasks. |
| Measuring tape | Ensuring accurate measurements for a precise installation. |
| Tin snips, metal shears, grinder | Cutting roof panels, metal sheets, and adjusting flashing with precision. |
| Hammer | Driving fastening nails and securing metal flashing in place. |
| Caulking gun | Applying sealant neatly to seal gaps, joints, and edges. |
| Galvanized nails, pancake head screws | Providing a secure attachment for roof panels and flashing pieces. |
| Masonry anchors | Fixing metal flashing firmly to the chimney wall for added durability. |
| Roofing cement, silicone caulk, butyl tape | Sealing overlapping flashing, seams, and ensuring waterproofing. |
| Metal flashing | Diverting water infiltration and ensuring water resistance around the chimney. |
| Field-hemmed panels, closure strips | Closing gaps, preventing snow and ice buildup, ensuring durability. |
| Ice shield, water protection layers | Protecting against water infiltration, snow, and ice buildup. |
| Wire brush | Cleaning debris and removing loose mortar for smooth surfaces. |
| Aluminum, galvanized steel, copper | Offering rust-resistant, compatible, and durable materials for metal roofs. |
Step-by-Step Guide to Install Metal Roofing Around a Chimney
Step 1: Prepare the Area
Begin by cleaning the chimney wall using a wire brush to remove any loose mortar, cracks, and debris. Inspect the mortar joints for gaps and seal them with silicone caulk. Check for any necessary repairs on the roof deck or chimney base. This step ensures the area is sturdy and clean for a proper installation.
Step 2: Measure and Cut Flashing Pieces
Use a measuring tape to calculate the exact dimensions of the chimney base, edges, and surrounding roof areas. Cut the base flashing, side flashing, and saddle flashing using tin snips or a grinder. Include a 1-inch bend in the flashing for a snug fit around the chimney base. Ensure the flashing pieces overlap by at least 12 inches to prevent water from entering.
Step 3: Install the Base Flashing
Position the base flashing at the bottom of the chimney, ensuring it extends beyond the roof material for proper water drainage. Secure it to the chimney wall with masonry anchors and reinforce the edges with butyl tape. Create a reglet groove using a grinder to tuck in the counter flashing, ensuring a watertight seal.
Step 4: Attach Side Flashing
Install side flashing along both chimney sides, overlapping the base flashing. Fasten the flashing with pancake head screws, spacing them 4 inches apart for durability. Seal the seams and corners with roofing cement and check for any voids or gaps around the edges.
Step 5: Secure the Saddle Flashing
Place the saddle flashing or back pan on the back of the chimney. This piece diverts water from the roof plane, protecting it from potential leaks. Fasten it securely with rivets and seal it with silicone caulk for added water protection.
Step 6: Lay the Metal Roof Panels
Start at the downhill edge of the roof and work your way upward. Interlock the field-hemmed panels, ensuring the male leg and female leg form a flush fit. Use closure strips under the edges to enhance water resistance. Secure the panels with pancake head screws, ensuring staggered laps for a seamless and durable finish.
Step 7: Seal Joints and Reinforce Gaps
Apply roofing cement and sealant to all seams, joints, and edges. Pay special attention to the chimney base, perimeter, and voids to ensure complete waterproofing. Use a caulking gun to seal the groove around the mortar joints and reinforce the flashing pieces for maximum durability.
Step 8: Add Final Flashing and Protection
Install apron flashing at the front of the chimney, extending it partially onto the roof material. Use galvanized nails to secure it and seal it with silicone caulk. For extra protection, add an ice shield and a chimney cap to direct water and snow away.
Step 9: Inspect and Test for Leaks
Inspect the installation process by checking the sealed joints, edges, and flashing pieces for any gaps or cracked sealant. Test the system with a water hose to simulate rain and ensure there are no water leaks. If needed, replace flashing, reseal joints, or reinforce with butyl tape to maintain a watertight and durable roofing system.
Additional Tips to Install Metal Roofing Around a Chimney
When installing a metal roof around a chimney, paying attention to details is key for a durable, leak-free, and long-lasting solution. Here are extra tips to ensure a properly installed roofing system while using the right techniques and materials.
1. Use High-Quality Flashing Materials
Choose flashing materials such as aluminum, galvanized steel, or copper to match the roof material. These provide excellent durability and resist corrosion. Copper flashing, for example, can be soldered to create a seamless, watertight seal, ideal for chimney bases. Use butyl tape and closure strips to reinforce adhesion.
2. Install a Cricket for Larger Chimneys
For chimneys wider than 24 inches, a saddle or cricket is essential to divert water and snow. This structure, installed on the uphill side, prevents water accumulation, ensuring proper water diversion. Combine this with ice protection materials to handle winter conditions effectively.
3. Overlap Flashing Correctly
Ensure each flashing piece, including step flashing, overlaps the previous one by at least 3 inches. This layering technique helps redirect raindrops and melting snow away from vulnerable areas. Use field-hemmed panels to align perfectly with the chimney wall and prevent leaks.
4. Secure Flashing Without Penetration
When fastening step flashing and counter flashing, avoid using penetrating fasteners on the chimney wall. Instead, embed the counter flashing into the mortar joints with a reglet groove to hold it securely. This method ensures a watertight seal and prevents damage to the chimney structure.
5. Incorporate Proper Sealing Techniques
Apply roofing cement, silicone caulk, and sealant to all gaps, joints, and edges around the chimney base. Use a caulking gun to seal grooves effectively. Seal the bottom flashing, side flashing, and back pan thoroughly to prevent water infiltration and increase longevity.
6. Conduct Regular Maintenance
Inspect the roof areas around the chimney periodically for damaged flashing, cracked sealant, or signs of leaks. Test with a water hose to simulate rainfall and detect voids or gaps. Replace any missing sealant and repair damaged flashing promptly to avoid costly repairs.
FAQs
How do you seal a chimney through a metal roof?
Sealing a chimney through a metal roof involves removing any old flashing, cleaning the area, and applying fresh flashing with proper sealant. Use a caulking gun to neatly seal all edges, ensuring a watertight and durable finish. Make sure the flashing pieces overlap correctly for added water resistance and longevity. Safety should always be a priority during this process.
How to Flash a Chimney and Prevent Leaks in Your Metal Roof?
Flashing a chimney requires using metal flashing to direct water flow away from the roof’s surface. Install step flashing under shingles and secure counter flashing into a groove cut into the chimney. Seal all joints with silicone caulk or roofing cement for a watertight barrier. This ensures leaks are effectively prevented.
What is Placed Around a Chimney to Prevent Leaks?
To prevent leaks, roof flashing is installed around the chimney. It is typically made of rust-resistant materials like aluminum or galvanized steel and redirects water flow away from vulnerable areas. Proper sealing with butyl tape or silicone caulk ensures long-lasting protection against leaks.
What to Put Around a Chimney on a Roof?
A cricket or chimney saddle is often placed on the uphill side to prevent water buildup. This structure diverts rainwater and snowmelt to the sides, protecting the chimney base. Ensure the slope of the cricket is steep enough to allow water to drain efficiently without pooling.
What Kind of Flashing Do You Use Around a Chimney?
Step flashing is used under shingles along the chimney sides, while cap flashing or counter flashing is embedded into the chimney for added protection. Both types are made of durable metal like galvanized steel or copper to ensure a tight, watertight seal. Proper overlap between flashing pieces prevents leaks.
How Do You Seal Between Roof and Chimney?
To seal gaps between the roof and chimney, apply roofing cement along the edges of the flashing. Use a caulking gun for precision and press the sealant into place with a trowel for a smooth finish. Ensure the area is clean of debris and cracks are filled to maintain a watertight seal.
How to Stop Roof Leak Around Chimney?
Stopping a roof leak involves inspecting the flashing for cracks or damage, removing loose sealant, and applying fresh sealant around all edges. Use a wire brush to clean debris and ensure a smooth surface. Reinforce the flashing with roofing cement or silicone caulk to prevent further leaks.
Installing a metal roof around a chimney requires attention to detail, the right tools and materials, and a methodical approach to ensure a secure and leak-resistant finish. By using high-quality materials like metal flashing, butyl tape, and field-hemmed panels, and following proper sealing techniques, you can protect your roof from water infiltration, snow, and ice buildup. Regular inspection and maintenance will further enhance the durability and waterproofing of your roofing system. With these steps, you now have the knowledge and confidence to achieve a long-lasting and professional-grade installation.
