Flashing a chimney on an acrylic roof coating involves carefully sealing the seams between the chimney and the roof to prevent water infiltration. Acrylic roof coatings are flexible, water-resistant membranes applied over roofing materials, so the key is to integrate the flashing so it bonds securely with the coating without damaging or disrupting it. Typically, this involves applying metal counter flashing snug against the chimney and pairing it with step flashing that lies under the roof shingles or membrane layers. The counter flashing is embedded into the chimney mortar joints or sealed to the chimney surface with a compatible sealant, while the step flashing interlocks with the roof surface and extends up behind the counter flashing. This layered approach directs water away from the chimney, guiding it safely onto the roof without allowing it into the structure. Simple checks at home include looking for any peeling or cracking of the acrylic coating around the chimney base or signs of water stains inside near the chimney. You can also gently test the flashing edges for looseness but avoid aggressive poking or prying.
For homeowners comfortable with basic DIY, inspecting the flashing annually and cleaning any debris buildup is usually safe. If you spot bubbling, delamination of the acrylic coating, or visible rust or gaps in the metal flashing, it’s wise to call a professional roofer who has experience with both acrylic coatings and chimney flashings. When consulting a contractor, ask specifically, “How will you ensure the metal flashing bonds properly with the acrylic coating without voiding the roof warranty?” and “What sealant or method do you use at the chimney-to-flashing joint to prevent leaks over time?” These questions help ensure that the roofer understands the nuances of acrylic coatings and will install a flashing system that maintains the roof’s integrity and longevity.