How to Install Chimney Cricket Flashing on a Metal Roof: Fast-Track Guide to Installing Chimney Crickets for Metal Roofs

Installing chimney cricket flashing on a metal roof is essential for preventing water leaks and ensuring the longevity of both your chimney and roofing system. Chimney crickets, also known as saddles, are small peaked structures built on the high side of a chimney to divert water around it. Flashing, meanwhile, creates a watertight seal between the chimney and the roof surface. Here's a step-by-step guide to getting the job done right.

1. Prepare the Area: Ensure safety by using proper fall protection when working on the roof. Remove any debris and inspect the area around the chimney for damage or weak spots in the roofing and chimney masonry.
2. Measure and Build the Cricket: Measure the width of the chimney to determine the size of the cricket. Construct the frame using pressure-treated lumber. The slope should match or exceed the primary roof slope to effectively divert water.
3. Install the Cricket Frame: Securely fasten the cricket frame to the roof deck and the rear of the chimney, making sure it sits flush against both surfaces for proper alignment.
4. Add Metal Cricket Sheathing: Cover the cricket frame with a suitable sheathing, typically plywood. Over this, install metal sheets (often galvanized steel or aluminum), ensuring that they overlap the existing metal roofing panels for a seamless look.
5. Install Step Flashing: Cut and fit step flashing pieces along the sides of the cricket and chimney. Tuck the upper edges beneath the adjacent metal roof panels or shingles, and extend the lower edges over the cricket flashing. Secure them using appropriate fasteners.
6. Install Cap and Counter Flashing: Add cap flashing over the top edge of the cricket, making sure it is tucked under the siding or stucco, if present. Then, install counter flashing over the vertical face of the chimney, overlapping the step flashing below to direct water away.
7. Seal and Inspect: Apply a high-quality roofing sealant along all flashing edges and fastener heads for extra water resistance. Carefully inspect the whole assembly to ensure there are no gaps where moisture could infiltrate.

From a designer’s perspective, while the functionality of chimney flashing is paramount, it's also essential to consider the aesthetic integration of the cricket with the metal roof. Opting for metal flashing materials and finishes that harmonize with the roof color and texture not only enhances waterproofing but also ensures a visually unified, professional look. In fact, using digital modeling tools beforehand can help you visualize the integration of structural roof features for the best results.

Tips 1:

Always use roofing materials compatible with your existing metal roof for best results. In case of an intricate chimney or roof design, it's helpful to model the cricket and flashing using a 3D planning tool before construction, allowing you to spot potential drainage issues and refine the design for both aesthetic and functional harmony.

FAQ

Q: What is the purpose of a chimney cricket on a metal roof?

A: A chimney cricket helps divert water and debris away from the back of the chimney, preventing leaks and water damage on metal roofs.

Q: Do I need special flashing for metal roofs compared to shingle roofs?

A: Yes, metal roofs require flashing materials compatible with metal, such as galvanized steel or aluminum, to prevent corrosion and ensure longevity.

Q: Can I install chimney cricket flashing myself, or should I hire a professional?

A: If you have experience working with metal roofs and flashing, you may be able to install it yourself. However, complex rooflines or large chimneys often benefit from professional installation to guarantee proper drainage and sealing.

Q: How do I ensure my cricket blends with the rest of my home’s design?

A: Use matching or complementary metals and finishes, and consider modeling the installation using digital design tools to visualize the end result before construction.

Q: How often should chimney cricket flashing be inspected?

A: Inspect it at least once a year and after major storms to check for loose fasteners, damage, or sealant failure, and address any issues promptly to maintain a watertight roof.