Join Date: Aug 2004
Location: Climbing, a mountain, Canada.
Interest: climbing and spraying
All of those numbers (10,000, 5,000, and 3,000mm) refer to the water pressure necessary to push water through the coating. However, in the real world, other factors like bends in the fabric can result in bleed-through even with less than actual pressure. In other words if you are laying on a 10,000 mm rated floor in a tent pitched in, say, a swamp, or on wet spring snow, in your sleeping bag and there's a pebble under your thermarest, (like the princess and the pea) you may get wet-through at that pressure point from body weight pressure.