Thanks for this great article Andy! I was going to suggest/request you share more info on your gear and gear hacks, I hope there's more in the pipeline!
Andy, why not just use a z-lite SOL and save yourself the hassle? I appreciate the flexibility of creating your own custom mat for a specific project or expedition but I also see a z-lite working well for most?
If you sleep directly on snow with a Z-lite style mat what you'll find is you lose about 40% of the insulation, as the bottom of the mat just sinks into the snow, so you have no air pockets under there, so less insulation (compare the ice/snow under someone who's slept on a z mat and someone who's slept on an air mat). Also, Z-lite style mats are great when new, but slowly lose their body, and so the R rating creeps down after a while (this is the problem with all testing, as it really only tells you about brand new kit). The Z-lite style mats are also trouble is snowy conditions, as you can't wipe snow off them (unlike a flat EVA mat), meaning the snow collects and then melts, which either means you have a higher chance of wetting out your sleeping bag, or you end up bringing ice into your tent (when I use a ridgerest I tend to carry it in a cover I've made, to stop snow getting on it when it's on my pack). An ideal expedition system needs to be two parts, both for redundancy (I've seen mats set on fire, blown away, punctured so bad they could not be mended, delaminated etc), and because the level of comfort required over a month of use is very different than over a weekend. Your body also changes, and gets thinner, colder, and more boney, so all this needs to be factured into your system. The old school expedition weight EVA mat plus an air mat is probably the best system, or two winter weight EVA mats if you really need a bomb proof system (say you're on a polar trip), but I think this exped mat system has a few things going for it that you'll not find in standard off the shell systems. BTW, I've been working on a longer piece on mats, as it's a very interesting subject, which I hope to post soon.
Thanks for the detailed explanation Andy, there's a few points I had not considered there. Definitely something to bear in mind for a Denali style expedition where increased comfort in cold conditions for 3/4 weeks makes a big difference.
I've never made a piece of kit before of this nature, might be a good Covid project to try out for the craic.
One thing you need to watch out for on very long cold trips is ice building up inside your air mat, caused by constantly blowing it up (the number one reason to use some kind of inflation device). On a Denali style trip the extra bit of luxury of two mats is worth it, and you can just leave your second mat at high camp. Having a full length Z-lite, and then a torso length 14 mm EVA mat (cut it into sections and tape it up, so you can carry it inside your pack), is a more robust option (maybe air mats become more important the older you get!). Also don't forget to draw on that chess board for those lazy days.
Thanks for this great article Andy! I was going to suggest/request you share more info on your gear and gear hacks, I hope there's more in the pipeline!
W.
Thanks. Yes, I'll share lots more!
Andy, why not just use a z-lite SOL and save yourself the hassle? I appreciate the flexibility of creating your own custom mat for a specific project or expedition but I also see a z-lite working well for most?
Cheers
If you sleep directly on snow with a Z-lite style mat what you'll find is you lose about 40% of the insulation, as the bottom of the mat just sinks into the snow, so you have no air pockets under there, so less insulation (compare the ice/snow under someone who's slept on a z mat and someone who's slept on an air mat). Also, Z-lite style mats are great when new, but slowly lose their body, and so the R rating creeps down after a while (this is the problem with all testing, as it really only tells you about brand new kit). The Z-lite style mats are also trouble is snowy conditions, as you can't wipe snow off them (unlike a flat EVA mat), meaning the snow collects and then melts, which either means you have a higher chance of wetting out your sleeping bag, or you end up bringing ice into your tent (when I use a ridgerest I tend to carry it in a cover I've made, to stop snow getting on it when it's on my pack). An ideal expedition system needs to be two parts, both for redundancy (I've seen mats set on fire, blown away, punctured so bad they could not be mended, delaminated etc), and because the level of comfort required over a month of use is very different than over a weekend. Your body also changes, and gets thinner, colder, and more boney, so all this needs to be factured into your system. The old school expedition weight EVA mat plus an air mat is probably the best system, or two winter weight EVA mats if you really need a bomb proof system (say you're on a polar trip), but I think this exped mat system has a few things going for it that you'll not find in standard off the shell systems. BTW, I've been working on a longer piece on mats, as it's a very interesting subject, which I hope to post soon.
Thanks for the detailed explanation Andy, there's a few points I had not considered there. Definitely something to bear in mind for a Denali style expedition where increased comfort in cold conditions for 3/4 weeks makes a big difference.
I've never made a piece of kit before of this nature, might be a good Covid project to try out for the craic.
Best,
Philip
One thing you need to watch out for on very long cold trips is ice building up inside your air mat, caused by constantly blowing it up (the number one reason to use some kind of inflation device). On a Denali style trip the extra bit of luxury of two mats is worth it, and you can just leave your second mat at high camp. Having a full length Z-lite, and then a torso length 14 mm EVA mat (cut it into sections and tape it up, so you can carry it inside your pack), is a more robust option (maybe air mats become more important the older you get!). Also don't forget to draw on that chess board for those lazy days.