Built-up roofing (BUR) is a traditional flat roof system made of layers of roofing felt and bitumen, providing durability and waterproofing. However, rusting can become a concern when metal components, like flashing, gravel stops, or fasteners, start to corrode due to exposure to moisture and air. Rust happens because water often pools on flat roofs, or there is poor drainage, allowing metal parts to oxidize. This not only weakens the metal but can also stain the roofing surface and eventually lead to leaks. A simple way to check your BUR roof is by visually inspecting for rust spots, loose or missing gravel, or bubbling and blisters in the layers. Pay close attention to seams, edges, and any metal attachments, as rust tends to show up there first. Using binoculars for roof scans or safely walking the roof with soft-soled shoes to avoid damage can help identify early signs of rust and wear.
If you notice rust or suspect it’s starting, it’s best to call a professional roofer experienced with BUR systems since repairing rusted metal and replacing damaged layers requires care and knowledge of roofing materials and warranties. When speaking with a contractor, ask whether they will inspect and replace rusted metal components fully and what kind of rust-inhibiting treatments they recommend afterward to prevent recurrence. Also, inquire about the condition of your roof’s drainage system since poor water runoff is often a root cause of rust and leaks. Keeping your BUR roof maintained by clearing debris and scheduling regular check-ups can extend its life and protect your home from water damage.