One of the most common causes of a metal roof leak is a problem with the screws holding your roof down. Metal roofing screws seal water out by compressing a rubber washer at the base of the screw head. When the screw is driven into the metal roofing panel the rubber washer forms a seal between the roofing panel and the screw head.
Here are 4 things that can go wrong:
- Over-driven screw: To ensure a tight seal between the metal roofing, the screw head may have been screwed in too far. This can break the rubber washer and it won't provide a protective seal.
- Under-driven screw: This results in the screw not going far enough into the metal roofing panel. The washer isn't compressed and no seal is formed, allowing rainwater to seep through.
- Screws driven at the wrong angle: This means the rubber washer won't sit flat on the metal roofing. Only part of the screw and washer will be sealed.
- Screws that have missed the timber or metal roof frame. The screw has nothing to hold on to, and so can't form a seal with the washer. This is a tricky one to spot as on the surface it looks fine, so closer investigation is required.
Small roof leaks can lead to big expensive problems such as mould, electrical problems, damaged ceilings and walls and ruined insulation.
If you suspect you have a roof leak, call your local metal roofing professional who can check your roof, screws and washers and make any necessary repairs.