The Grill Pad is made of an exclusive material crafted from fiber cement making it heat- and weather-resistant, flexible and durable, and at 8 pounds it is heavy enough to stay anchored to the ground. The unique cement fiber material will protect your deck better than plastic and metal grills pads because it will not rust, and it will not melt or degrade in sunlight. The pad will not stick to a composite deck surface as it does not contain rubber backing material.