For dry, uncompacted snow? The question came up during the recent cold snap in British Columbia, and as I was building snow piles on top of my huddled-together-containers. How much is enough? So far, I have come across the following "answers", applicable to dry snow with about 10% volume water: 1. Ten inches of fresh snow with a density of 0.07 inches, seven percent water, is approximately equal to a six-inch-layer of fiberglass insulation with an insulation R-value of R-18. 2. One inch of snow has an R-value of 1. Any thoughts on this?