The strong and long-lasting benefits of a screw-down metal roof begin with the selection, placement, and installation of the fasteners used to anchor panels to the structure. There are hundreds of fastener options and variations, but fear not! It's easy to navigate the world of fasteners once you learn a few general rules of thumb: what the numbered sizes mean, and how to determine what length you'll need.
Unlike nails, screws are not easily malleable, nor do they loosen during normal expansion and contraction. Screws work best when forces will be applied in multiple directions, or if extra weight will be applied. The threads of a screw grip and “bite” into the material to create stronger and more secure joints. The gauge or thickness of the screws are listed similarly to brads but are more like nails in that the higher the gauge, the thicker the screw.
The placement of fasteners could make all the difference in the need for maintenance and repairs. Screws should be installed in the flat of the panel. Avoid placing screws at the top of the rib, with the exception of manufacturer’s recommendation or to connect a seam.
Fasteners placed at the top of the rib prohibit the establishment of a secure seal. This method could also potentially force the screw to tilt and stretch the screw hole opening, hence breaking the seal if the opening grew wider than the washer. Even worse, placing fasteners in the top of the rib increases the risk of screws pulling in the case of high winds.
Installing screws in the flat of a panel creates a stiff diaphragm, allowing for more solid wood below the panel surface to fasten screws into place more efficiently.
RapidMaterials offers a wide selection of fasteners of many variations. Find our fasteners available for order here.