SHOULD BE REPLACED ... As they can compromise the structural integrity of the roof. Over time, rust weakens the screws making them susceptible to breaking or loosening, which can lead to leaks. As rust is corrosive this can spread from the screws to adjacent metal sheeting accelerating the deterioration of the entire roof. Many insurance policies require owners to maintain the roof, which includes replacing rusted or damaged roofing screws. Contact Millenium Roofing, for metal roof and colorbond roof sheet rescrewing, minor roofing repairs, roof cleaning, roof sealing & roof painting in Cairns, Port Douglas, Mareeba, Mossman & Innisfail regions of QLD.