A range of washers specifically designed for use within the roofing industry. Our selection includes traditional spat washers, also commonly knows as dowty washers, which are widely used with hook bolts when fitting corrugated roofing. We also carry large stocks of sela washers and caps, a more flexible, durable and weatherproof alternative to spat washers. Simply purchase the sela washers, and then select which cap you would like to go with them. Once the cap is pushed onto the washer, you have a waterproof seal. The caps are quite difficult to get off once pushed onto the washer, so we wouldn't recommend testing too many our before fitting.