We all know that most synthetic insulation in jackets, etc. degrades over time, especially with repeated compression. I never considered the impact on my sleeping pads. I’ve had a Big Agnes insulated pad (primaloft I think) for years and it spends most of the time rolled up. It was a 4.1 R pad when new, but how much has it lost, if any? Any studies / experience here?
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Pad insulation longevity
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Has no one had any experience with a pad losing insulation? Any speculation that a 5 year old pad is still providing its original warmth?
I have a Thermarest Prolite Plus; that’s the oldest pad I still own.
Off course I have no scientific/engineering-like-gear, but after three years of use it stills feels as warm.
In all honesty, it spends a lot of time in the gear closet; I prefer my NeoAir XLite S.
I wonder what Thermarest has to say about this. I’ll try contacting them.
I think mostly, the insulation value is determined by the thickness
as long as the pad is the same thickness, it should be the same
if you had a space greater than an inch or whatever, and all the internal insulation clumped at the bottom, then there would be internal air currents which reduce the warmth significantly. Like an air mattress with no internal insulation
The thermarest NeoAir pads dont have any actual insulation in them so they wouldn’t be effected.
I would think that other mats like the down mats would loose some loft if stored compressed just like a sleeping bag or a jacket would.
My pad is an air mattress with synthetic insulation. My concern is the synthetic insulation has degraded. Foam pads should last pretty much forever.
Well, standard foam pads do loose a bit over time. The old NightLite pads from Gossamer Gear used to post a warning about it. And yes, I can confirm that the “Wally World Blue” pads do to after a few seasons. Good or bad? Well that sort of depends. On hard level surfaces, they tend to be worn in where the most weight is conforming to my body better, BUT not supplying as much cushion/insulation. In my multiple layer pads, I have actually removed old tape (with only minor damage to the foam,) and retaped the sections in a different order. For insulation, the loss of “loft” is never good if you cannot rearrange it.
I had a Thermarest Prolite. After a while it delaminated – a bubble formed and then got wider and higher.
It was where when I laid down on the pad, I put all my weight with my hand on the pad. I think there was too much pressure.
I returned it to REI (bad old days when there were unlimited returns) and got a new one
Since then, I don’t put all my weight with my hand on the pad. I put my hand to the side. No sign of delamination yet.
The delamination was slow enough I just finished my trip and replaced it before the next trip. Not a catastrophic failure.
Jerry Adams explains inflatable pad delamination and it’s a common occurrence at least with some of the Thermarests I have used.
As far as inner pad foam degradation, well, I’ve never seen it happen like with a polarguard fill bag but the test is easy—take your old pad out in the backyard tonight and sleep on it. Preferably at 20F. You’ll know soon enough if the foam is ruined.
Then again, I treat all my inflatables like socks—Disposable after a season or two of backpacking. A well-used inflatable pad (300 nights?) needs to be replaced before any sudden surprises.
My replacement Prolite is now 4 years old. About 300 nights. So far so good. (which isn’t inconsistent with Tipi : ) My previous pad delaminated after about 180 nights.
There was someone several years ago that posted that her pad delaminated a couple times. Each time Thermarest replaced it for free. She was a full time user so maybe got 300 uses per pad before delamination.
Picture of delamination (circled):

Jerry—Excellent pic. It shows exactly how the poorly engineered Thermarest starts its journey down the rabbit hole—with a few tiny bladder-bulges. These “delams” are not self-healing, by the way.

My Thermarest started in the same exact way, with a couple small bulges. “I can live with that!” I said but I was on a long backpacking trip and dangit if after 3 more days became this—

POW!! Luckily as is visible in the pic I had my Ridgerest Solar pad at 3.5R which I could double up for a torso pad at 7R. I also had a NeoAir All Season buried in a cache 10 miles away. Oh and btw, such a bulge DOES NOT make for a good pillow.
Was really hoping to get more experiences on air mattresses and synthetic insulation, I think we’re all familiar with self-inflatables and delamination.
First the glue fails, then the insulation slides to one end, then your pad has cold spots.
POE is out of the biz, but I imagine other companies provide the same experience.
Paul S says: “Was really hoping to get more experiences on air mattresses and synthetic insulation, I think we’re all familiar with self-inflatables and delamination.”
You must’ve not read my first post. I have never seen a Thermarest inflatable lose foam loft or have it degrade, even after 30 years of storage. So point is, way before any such foam degradation occurs the pad will either get pin holed or have a leaky valve or YES delaminate. Glue degradation is a much bigger problem with Thermarest inflatables than synthetic insulation failure.
sorry Paul : (
So, Tipi, was the delamination where you put all your weight on the pad with your hand getting down onto your sleeping bag? My theory for why it delaminates
My picture was like after a week of use, only gradually getting worse. Maybe if you didn’t blow so much air into it you could limp along for a few days until the end of a trip
I’ve had the same BA Q Core for over five years. Since it’s heavy I only use it in winter ( ugh what a brick! ) but it’s still going strong this winter, ( So far three weeks straight use ) and it spends all the rest of the year rolled up as it was shipped to me. Despite the weight it’s an absolute delight to sleep on as the rest of the year I use a skeleton torso pad with my backpack under my legs.
I emailed Thermarest years ago about the pad delamination problem and they said it was due to “overuse and body oils.” And in 35 years of almost continuous Thermarest use—from the old orange standard with the metal valve to the old original Ultralight pad to several Camp Rests and Base Camps and Explorer pads and Backpacker pads and several Prolites and Prolite Pluses, a Toughskin, 3 yellow 40th Anniversarys, a NeoAir All Season and a current Trail Pro pad, with all these models and in all these years I’ve had around 8 to 10 pad delaminations as pictured in my post.
Some guys go a lifetime without such a failure but then I have lived on these pads literally for thousands of bag nights. When I lived at my NC ridgetop Tipi for 21 years, all I used was Thermarest pads for sleeping. They will delaminate eventually, it’s the nature of air pressure, foam, a thin shell, and suspect glues. Along with a Thermarest design system unable to solve this problem, even after 35 years.
And no matter how you toss and turn as you sleep, no pad should pull apart due to body mvt. Oops, my pinkie finger tore the shell. Oops, my elbow blew out a seam. Oops, my body weight caused a giant catastrophe BULGE.
There are several options for backpackers on long trips who depend on an inflatable pad for comfort and/or survival (think frozen ground at -10F).
** Carry a Ridgerest Solar pad as backup—offers 3.5R spread out and 7R doubled up.
** Carry the lightest smallest NeoAir and keep it in your pack. It’s what I did on my last trip.
** Cache an emergency Thermarest at the trailhead and circle back if disaster strikes. I did this on two occasions: Once when my sorry Exped downmat blew a baffle and I hiked 12 miles out of my way to get a cached Prolite Plus. Last time my yellow pad (above) blew a gasket and I retrieved a Neoair all season from a cache 10 miles away.

Here’s my emergency NeoAir which I keep with me in the pack. It, when inflated along with my ccf Solar pad will keep me going for another 2 weeks.
Do all of your pads delaminate at the same place? When you get onto your pad do you put all your weight there with your hand?
Laying down, the most weight is at my hips, but it’s only a portion of my total body weight and it’s a bigger area than my hand. Much smaller pressure.
It makes no sense body oils would do it because that’s on the outside. I suppose it could soak in.
overuse? hmmm, I suppose it’s reasonable to trade off low weight for reduced lifetime. I had 180 days before delamination which seems a bit short of a lifetime. 300 days and still going on my 2nd Prolite seems more reasonable.
I have a neoair xtherm. It uses chambers of mylar or something like that. I’m wondering if, since it’s not foam or puffy insulation, if the insulation will never really degrade.
the neo air has layers of aluminized mylar baffles
if the aluminized coating came off, internally, you wouldn’t see it or anything and it would loose some of it’s insulation value
if the internal baffles came un-attached, it would puff up, something like the delamination pictures so you’d see it
10 or more years ago I had a POE inflatable with synthetic insulation laminated to the top surface. I loved that pad at the time but after awhile the insulation started coming loose and bunching up. At the time I suspected that moisture from inflating by mouth was the culprit, but I will bet the constant folding and rolling didn’t help any. Logically I think that design is destined to suffer a failure of the insulation attachment.
I made the move to NeoAirs and rely on them still. To my mind the thermal barrier design is superior to filling the mat with natural or man-made insulation. Yes, it is possible for the reflective coating to come off the Mylar film, but I think you *can* see that by holding the pad in front of a strong light. And if that does happen, TAR’s lifetime warranty will take care of it.
NeoAirs are great, but I do not reccomend putting any inherent trust in their “R-Value” rating system, or anyone else’s for that matter. As one who deals with this in the architecture profession, the pad companies attempt of quantifying “R-value” is a noble quest, but they have a long way to go. Because NeoRests solely depend on their thickness for their R-value, unless you are constantly filling the thing up over night to maintain its “loft”, it will never remain consistent as the air/ground temp and humidity change during the night. In above freezing conditions, this is not an issue. In sub freezing conditions, this could be catastrophic.
Until there is some agreement for creating a common standard amongst manufacturers, it’s all just marketing hype.
If you are going on any trip where you might have a few days of sub-freezing weather, always supplement with a ccf pad.
Either way, sleeping pads are kind of like people: Over time, depending on use (and abuse), we all get bloated, flat in spots, or brittle over time, but never in the same way, or at the same time.
(Too bad I can’t go to REI for that knee replacement.)
Matt – good info on R-value…I always assumed that measurement was straightforward and easily comparable between pads. I am often far too trusting.
Personal experience with the NeoAir XLite is that I am comfortable down to +20F on them given my sleep system. I find that personal experience is the only thing I can truly rely on, and that’s why this forum is so valuable. Yes, individual personal experiences differ, but over time I think they converge to something that is more or less universally applicable.
Paul, I’ve often wondered the same thing. I’ve had a couple of catastrophic Exped synmat fails (ahem…always my fault…ahem…or at least I can blame CharlieDog) and it was fascinating to see the layer of synthetic insulation in them and how the pad was constructed. If Richard found that a week of wearing a Rab Xenon synthetic puffy made it lose a good percentage of its CLO value, what would year of folding/rolling/inflating/deflating/smooshing a layer of the synthetic insulation do to the exped?
[I also have an Exped Downmat UL7 that has been my absolute favorite pad to date, but in the middle of one night Charlie (yes, him again!) pounced on the pad and punctured it from the top – sending a geyser of down into my mouth, eyes, and tent before I could locate the hole and stop the bleeding. I was able to patch the hole and save the pad, but I’ve never had the chance to test the pad in really cold temps since. They have temporarily discontinued the pad so I can’t replace it just yet (Exped assures me they will bring it back in 2016), so a below-freezing Big Bend trip in January should be an interesting test of how much insulation I actually lost and how well it’s going to work for me. I think I’m going to go ahead and bring a CCF to supplement just in case…despite the extra weight of the now-lighter downmat…..]
Anyway – good question about the synthetic insulation that really hasn’t been answered just yet….
Paul,
WHY did your BA insulated mattress “… spend most of its time rolled up.”??? That’s a sure way to ruin any insulation, especially synthetic fiber insulation.
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