The NRG Washer Greenboard 500/box are an integral component of the NRG Greenboard insulated wall system, engineered to distribute the load of the fastener across a wider surface area of the polystyrene board. EPS boards are lightweight and can be susceptible to damage if fastened with standard screws alone. These 50mm washers are designed to sit flush against the board, providing a “positive fix” that prevents the screw head from burying too deep or pulling through the core. This ensures the boards remain perfectly flat, which is critical for achieving a high-quality, crack-free render finish.