Thermarests and Ripoffs

Alright, I’ll admit, I’m a cheapskate, I’ve never bought a real Thermarest, but I have bought self-inflating matresses, and figure the principle is the same, a sheet of open-celled foam inside the matress expands and then you close the valve. How come my matresses don’t fill up as nicely and firmly as the Thermarest display models at REI on their own? I get them firm by blowing air into them and they get nice and firm - is that what they are doing at REI? Is it necessary to blow into a band name Thermarest to get it like that, or are they that much better that they get that way on their own?

The mattress has to be

First, always store it unrolled and the valve open. Under your bed is a good place.

The initial uses will require manual inflation to firm it up after self inflation. This will lessen with time and use. You will probably always have to add a little lung power to achieve the firmness you want but its no big deal.

Temperature also has an effect; warmer air temps will yield faster and fuller self inflation.


"Buyer beware" of the thermarest knock-offs. A buddy went with a knock-off and when he inflated it, its form was more of a bladder than a mattress. No way he could sleep on it.

Also, I haven’t seen a knock-off yet that wasn’t heavier and bulkier (un-inflated) than a thermarest.

I’ve got two thermarests. The first I got when I was in college, so it must be 30 years old. The other I bought at a rummage sale 15 years ago. I still use both. One has a couple of patches. The other I replaced the valve.

Yeah, I’m going to splurge here soon
and get the genuine article. The materials are nicer, they aren’t lumpy, and I’m sure they are more durable. Just wanted to see before I bought if the self-inflation was better, too.

I Have A Knock-Off
also and it does need to be “trained”. I have done a poor job in training, so mine still needs training. I let mine sit in the tent for a half hour or so with the valve open. I then have to manually add a few breaths of air. I love it and mine came from Walmart and was about a third the price of the “real thing”.

Happy Paddling,


I’ve always blown into my thermarest(s), you’ll never get full inflation when letting them simply air-inflate and I’m generally impatient anyway. They say you should be careful with inflating it with your moist warm breath in winter due to condensation but I’ve never had a problem, hasn’t turned into a water balloon yet! In anycase, winter camping is more effective with a piece of cheap closed cell foam as it has better insulating qualities than an air pad in winter. In winter, I’ll bring two, a Prolite 4 and a foam pad…


Needs training
as was previously mentioned.

Back about 1979 or 1980 when I was in retail, Thermorests had just hit the market. I had seen them at a dealer show, and while I thought the price was outlandish ($29.95!) I had demoed one on a bed of rocks and was convinced of the concept.

So the first mattresses arrived, and I excitedly showed a couple of customers (who were shopping for foam pads) the new toy. Pulled it out of the wrapper, opened the valve and dropped it to the floor. Nothing. Pregnant silence. Embarressmant. “Maybe we will just get foam pads.” said the customers.

Read the small print on the wrapper!


Same here.
Although I have found that with them not completely blown up to the point where you can’t get any more air in they are more comfortable.

Maybe they are not supposed to be hard ???

Merry christmas and



I store mine inflated
I don’t have a flat place to store my Thermorest, so I inflate it and stand it behind the door of our spare room. To put it away, I let it self inflate, then add a few puffs of air to make it stiff enough to stand by itself.

When camping, I let it self inflate, than I actually bleed a little air out until it is the comfort I want. I have the 2" thick “CampRest” model, and it is perfect for my heavier weight. It is too hard for me when it is “pumped up”.

It will self inflate slower when it is cold too.

Thermarests - Double Duty
We’ve used Thermarests for the past four or five years, with no problems - we do add a puff of air or two for sleeping, tho. Ours are also used as seating in the VOLKSKAYAKs - folded double under, single up the back - and they work great - nice and soft, warm, very comfortable. We store 'em inflated, behind the living room couch where the doggies can’t get the them.

Ok, here’s another question
On the thermarest website, the Prolite 3 is 20 X 72 inches, but its rolled size is 11 X 4.1 inches. The Trail model is the same width rolled as it is unrolled. With the Prolite, do you fold it in half along its long axis before rolling it?

Prolite models come folded + rolled
I bought a women’s Prolite 4 this season and immediately put it to use on a 9-day kayak camping trip. GREAT pad!

It comes folded down the long axis. However, you do not have to fold it (I don’t). The non-Prolite models simply come rolled at full width; only the Prolites are folded before rolling.

I suspect it’s partly a marketing tactic: the folded ones immediately are distinct from the rest of the models, and they are very small when fully compressed. The foam has small cutouts to allow greater compression without losing cushiness when inflated. This has the side effect of self-inflating faster than the non-cutout models do. I know because I have owned three ThermaRest self-inflating pads and one closed-cell foam pad, the Z-lite.

Ditto the other comments about knockoffs. I first bought a knockoff, and it soon began leaking. All of my ThermaRests are still going strong, including one that got almost daily use for a year (used it as a mattress). That one is now more than 10 years old. (I have three of them for different uses–none are identical.)

You do have to “train” the self-inflaters. After that, store them with some air inside, or store them with the valve open and the pad allowed to inflate itself.

ThermaRests are expensive but they last a long time. Worth every penny.

I was just …
looking at the thermarests. So do you reccomend the Prolite vs the regular?

I’m a cheapscape too!
I have a “pre-owned” car; I have a TV that’s not a plasma; My computer only got a CD burner instead of a DVD burner; etc…

But when it comes to back country gear, I got the best I can find (at the time). I keep having vision of a leaky tent on a rainy night, or a deflating thermorest when it’s 30 degrees, 3 days from civilization! It just doesn’t appeal to me! ;o)

This fall, that point was brought home again, in a less than pleasent situation. My much abused stove of 15 years started to lose pressure, slowed down cooking and finally wasted so much fuel I had to cut my trip short by 1 day. Although I was not in danger nor total misery (unlike a leaky tent or deflating pad), I nonetheless lost a day of enjoyment. It re-enforced my believe that I don’t want to go into the back country with gears of questionable quality.

The truth is, gears like tents and pad last for quite a long time. So, spurging for a quality one will probably works out cheaper in the long run by not having to replace them for years to come.

Prolite 4
With the bright orange Prolites, they can double as a signalling device!

I would spring for the Prolite 4 myself, being a more light-freak when I’m backpacking or kayak camping. I’m also a short 65" so the 3/4 Prolite 4 is pretty much a 4/5ths to me. :slight_smile: and I simply use my pack as a foot prop.


Folding vrs rolling
From a longevity standpoint, the more you fold and especially if you fold on the same axis each time, the material is going to be a wee bit weaker each time, as opposed to rolling. The idea of stuff sacks and randomly stuffing in say, a sleeping bag, is that the randomness of it promotes the longevity of the sleeping bag. So, if you do have a choice, rolling it flat is something that is good to do. Having said that, it is most likely fine to fold, as it’ll probably get poked by something sharp long before the material actually fatigues to the point of ripping! And I do fold my Prolite 4 and put it in my backpack because it is more suspension on the frame and is much faster than trying to get it stuffed into those little sacks that you can get for your thermarest!


I just bought a new backpacking thermarest. This new full size 25" wide, 1.5" thick Thermarest packs down to 5" by 13"( approximate), half the size of my old full size Thermarest. It’s really great for kayak camping. It too is in training. By the way, my old Thermarest is about twelve years old and it still works great. It’s a good investment. Merry Christmas and Happy Hanukah! Franklin

Big Agnes Mattress
To sort of change the subject. Have you considered the Big Agnes Mattress? I haven’t used one, but I took a trip in the fall with a guy who did. He loves his.

It is NOT self inflated, but he insists that it is no big deal. It inflates easily by mouth. He says it is far more comfortable than a thermarest. His Big Agnes is much smaller than my thermarest uninflated. It is about the size of a nalgene bottle.

If I’m ever in the market for a third mattress I’m going to consider the Big Agnes. I say “third mattress” because the two thermarests I have will last forever.

RE: Slumberjack pads
I too had a problem with a Slumberjack. It had a slow leak from teh get-go, so I returned it for credit.


I bought a knockoff and the cover separated from the foam making it useless.

Rather than worrying about training your mattress store with some air still in it. To fill it pull it out and open valve first thing in camp. Then set up your tent. Put the Thermarest inside and then attend to everything else. When it’s time to hit the rack your mattress will be almost full. I like mine hard so I add a couple of puffs. I should mention air temperatures affect the mattress. In the winter it takes much longer for a mattress to self-inflate and even then it won’t inflate as much as in summer.