SilNylon is a nylon fabric impregnated from both sides with silicone. This allows an extremely thin and lightweight nylon fabric, to also become extremely strong. The Haven benefits from a 20d SilNylon outer - effectively this makes, what would otherwise be a 2.5kg tent, a 1.95kg tent with a much higher tear strength and superior durability to standard PU coated tent fabrics. Silnylon does not form rot and mildew like standard PU coated tent fabrics can. The Haven’s flysheet has a hydrostatic head of 2000mm plus, which is more than enough to keep even the heaviest of rain from getting through it. Due to being a Silicon coated fabric, SilNylon can not be taped at the seams. Instead the seams can be sealed with a silicone seam sealant, provided with the tent. Once sealed the seams will be waterproof for life.