Chris Townsend is a world-leading authority on outdoor gear. In his weekly column, he assesses new innovations and tests exclusive early samples of new kit. This week he is impressed by Lightwave’s innovative new approach to single-skin tent design with the S20 Sigma

Revolutionary new products don’t come along very often but I think Lightwave have one with the fabric for their new Sigma range. This consists at present of two single-skin tents, the s10 and s20, for solo and duo use. Now single-skin tents have always had one big problem: condensation. This has made them unsuitable for use in the UK and other countries with damp climates. Over the years I’ve tested several and have always had too much dampness inside for comfort with the inner walls often dripping with condensation and pools forming in the corners of the groundsheet. Only with such good ventilation that the wind can blow through the tent has it been possible to reduce condensation, and even in such tents condensation is copious on still nights. Also, massive vents rather defeat one of the potential advantages of single-skin tents, which is that they can be sealed for maximum heat retention and weather resistance.
When I heard that Lightwave had a new fabric that overcame the condensation problem I must admit I was dubious, having been disappointed by such claims before. However after three nights in damp rainy weather I am pleased to say that I’m very impressed. This new fabric really does work. It’s called X-tex and is a polyurethane-coated nylon with activated carbon. The latter is the key to the performance as it is highly attractive to water so condensation is absorbed into the fabric. No drops are visible on the surface and the fabric feels dry to the touch. That’s the case even when the outside is wet with rain. Conditions were certainly right for condensation on the nights I was camping as shown by the silicone-coated nylon porch, which was running with moisture every morning. There was a little condensation on the raised groundsheet walls too and a few drops on the taped seams, but nowhere near enough to cause even slight problems.
Single-skin tents are roomy for the weight as there’s only one layer. They’re easy to pitch as well. The X-tex fabric is much quieter in the wind than most tent fabrics too and also dark inside, a useful feature on light summer nights. The Sigma tents have an inner door to the main tent as well as the porch door. With both doors closed the tents are pretty well sealed off from the weather.
Lightwave s20 Sigma porch
The basic design is a simple two-pole cross-over dome. To this Lightwave have added an extra short pole to give more space at one end and to aid stability. The tents can be pitched with six pegs. Another six are needed for the guylines in windy weather. Pitching takes little time. Having adjustable loops or double eyelets at the pole ends would be useful though as the poles are a tight fit.
I’ve tried the s20, which weighs 1.72kg. That’s a bit heavy for solo use – the s10 weighs 1.42kg – but I did relish the space. There was room for all my gear including the pack. I was also able to stand the latter up when packing inside in heavy rain. Headroom is excellent in the centre and pretty good everywhere due to the steep walls. The porch runs along one side of the tent. It’s not that roomy though – fine for one but probably not for two, especially if there were wet packs and clothing to store. Only the short side of the porch opens, making for a small door. The inner door is the same. A bigger porch or perhaps even two porches would be welcome.
Lightwave s20 Sigma pic 2
Overall though the s20 is excellent. It stood up to strong winds and heavy rain on one night and was always dry inside. Pitching it after it had been packed away with the outside wet it was still dry inside.
X-tex is an exciting fabric and Lightwave has utilised it well. I’m looking forward to future designs. It is quite expensive but then there really is nothing else like it.