To ascertain the level of water penetration in any material, you need to check its Hydrostatic Head Rating. According to Go Outdoors’ guide to waterproofing, the definition of waterproof is 1500mm hydrostatic head. This means that a column of water up to 1500mm can sit on the fabric before any water ingress. Our outdoor cover fabrics can withstand 2000-2500mm and greater.
Understanding the hydrostatic head will help you choose whether or not your cover will protect your vehicle from rain downpours and heavy snow. This is the difference between waterproof and water resistant.