Exposed fastener metal roofing systems use screws or bolts with rubber or neoprene washers that seal around the fastener to prevent leaks. Over time, these fasteners can experience common failure modes such as rusting, washer deterioration, and loosening. Rust forms when the protective coatings wear off or if the fasteners are not made from corrosion-resistant materials. Washer deterioration happens due to UV exposure and weathering, causing cracks or flattening, which compromises the seal and lets water seep through. Loose fasteners can be caused by thermal expansion and contraction of the metal panels or improper installation, leading to gaps where water can infiltrate. These issues tend to develop gradually, often resulting in small leaks that worsen unless addressed.
To diagnose potential problems, homeowners can conduct a simple visual check by looking at the fasteners for rust, damaged washers, or signs of looseness like raised heads or gaps around screws. Gently pressing around the fasteners can help identify any movement. If you notice any corrosion, missing washers, or soft spots, it’s a good time to call a professional roofer. When consulting a contractor, ask if they use fasteners with EPDM washers rated for long-term UV exposure and if they recommend periodic retightening during maintenance. Also, inquire about corrosion-resistant fastener materials suitable for your climate. These questions ensure the job respects manufacturer warranty requirements and the specific needs of your metal roofing system for lasting protection.