View Full Version : Therm-a-rest Question

Mike Drinkuth
09-17-2002, 12:24
OK...Simple question

The Self-inflating "Ultralite" weighs 1lb 8oz
The "Ridge Rest" weighs 14oz

I know how much more comfy the self-inflating is but does anyone carry the extra weight? Is it worth it? Also does a self-inflating stand up to the AT?

My guess is NO but I wanted to see what everyone else thinks cuz that's a BIG weight difference!

09-17-2002, 14:05
just finished 35 mile bucktail path in cameron county, pa, this weekend using ridgerest cut in half(36 in.) and after 3 nites am ready to work my 3/4 thermarest back into my liteweight system. my son did katadin to duncannon, pa in 2000 using a full length ultralite thermarest and said it was welcome inthat he used the hard plywood shelter bunks often. i love to walk but if it were not for my friends complaining of my horrendous snoring i wouldn't believe i even slept most nites. i think it is possible that i really have not spent enough nites on the ground to get used to it, since i rarely can get more then 4 days off in a row.

SGT Rock
09-17-2002, 14:14
I personally didn't feel much difference between my Thermarest and my closed cell foam pad (not a Ridgerest). I've still got the Thermarest collecting dust in the garage.

09-17-2002, 15:54
Maybe I should let my t-rest and r-rest collect dust in the garage and just break down and try a hammock. the weight vs. comfort debate goes on. are there any hammocks that will cradle a water buffalo?(215lbs.)

09-17-2002, 16:18
Like most equipment, the question is does the weight justify the safety and comfort.

I think that closed cell pads work best for those hikers with young bones. Also, sleeping on the ground is usually softer than sleeping in a shelter.

Most thru-hikers value a good nights rest. So, probably close 50% of the thru-hikers carry a therma-rest

By the way, the 3/4 Therma-rest guide lite is 1 lb, 3 oz (19 oz). The Therma-rest 3/4 ultralite is 1 lb. The lighest closed cell pads are about 8 oz. So, the "weight premium" is 8 to 11 ounces.

Now, the question is what works for you? I'd suggest that you spend the $18 to $20 and buy a Ridge Rest. Then try sleeping on a hard floor with it. If it works for you, then don't buy a Therma-rest. If you want more padding, then buy a Therma-rest.

For what it's worth, I carried a Therma-rest, and haven't punctured it yet. But I also tried to be careful about where I spread it out, and tried to keep a ground sheet under it.

09-17-2002, 17:09
I concur with Peak's remark about closed-cell pads and young bones. If yours are young, you can afford that more spartan sleep. But as your bones get older, the heavier pad sure becomes much more comfortable. So, I use the 3/4 Thermarest ultra-lite under my old back, blown up very hard. It folds, before rolling so, once rolled, occupies less room then a loaf of bread and goes inside my pack.I dangle nothing on the outside but water. Actually, as the weight dimenished, so did the pack volume.

Anyway, take some marbles to an outfitter and put both mats on them, lie down and see which levels them out, which you had rather sleep on. Dont just lay them on the floor but put at least something under them to represent irregular ground.

Mine is slightly over 1 pound as I carry the stuff sack and repair kit, both of which I am probably going to stop lugging around-dont think I need either one

09-17-2002, 20:25
I carried the larger Thermarest on my Thru. Had no problems with it. Of course I am a senior citizen, and need to be comfy. 1.8 lbs is not much, you just have to cut weight somewhere else.

SGT Rock
09-17-2002, 20:59
The young bones argument probably has merit. But just a word of caution, if you go hammock, it does not mean you will not need a pad. In a hammock, you will have the loft of you bag compressed under your body weight, so you loose a lot of insulation at that point, and this area creates a large surface area for convective heat loss, to combat this you will be best serve by a closed cell foam pad. If someone tries to tell you a radiant heat reflector works too, they are ignoring physics.

09-17-2002, 23:56
Yes you are right SGT. But the hammock will cure his complaining about comfort. Then he can used his closed cell pad and even cut it in half.

Uncle Wayne
09-18-2002, 07:27
I have to agree that old bones vs young bones make a difference on this subject. I have used both but the older I get the better I sleep on the thermarest than the closed cell foam. I consider the thermarest one of my "luxury" items!
One advantage to the closed cell foam is it can be used as something to sit on during a break. Regardless of where you're at, just drop it and sit down. Keeps the "butt off the ground" and dry during early morning or rainy weather. It can withstand more abuse than the thermarest. Have to be a little more particular with the thermarest.

09-18-2002, 07:49
I lusted after the Hennessey A-Sym but was heavier than 200 pounds. Called Tom Hennessey and at no extra charge he beefed mine up with 1600 pound ropes for a hammock that just goes over the 2 pound mark. Call him. Plus, there are other models for that weight range but I wanted the stealth version of the A-Sym. Here's his site:


09-18-2002, 13:17
I have a ul-asym and it holds my 250 just fine. Hennessy does have models rated up to 350 availible.

The Weasel
09-18-2002, 19:34
I carried my Therma-Rest FULL LENGTH "ultralight" model from Springer to Damascus, and YES it is worth the weight. That was my "luxury" item, and I'm glad I had it when I was in shelters, especially, with flat HARD floors.

The WEasel

Hammock Hanger
09-18-2002, 20:26
I am (or was) using the same pad for over 10 years. That was long sections, hiking every night during the summer in the ADK as an instructor, using it as a sleeping mat when too many extra guest were in the house. What I'm trying to say is I abused it to death. It still works great. I patched one hole the first year I got it. The patch and the matress have held up fine since then. When I changed to my hammock and was in the process of cutting back some weight I let it go. I am able to sleep in a shleter with no pad, so as far as comfort goes I'm not good at comparing. That said I really don't see any difference between the z-rest and the thermarest. There are many hikers who will disagree and would never part with theirs regardless of weight. I know of at least 2 who sent them home and asked for them back. So to some it does make a difference. In cold westher it makes a difference in the hammock but I'm still unwilling to return it to my weight ratio. Hammock Hanger

09-19-2002, 09:20
I keep wrestling with trying to move to a Z-Rest or other closed cell pad and give up my Ultralite 3/4 Therm-a-Rest to save about half a pound. I think I've decided to keep the TRest, even though I'm moving to a hammock since (a) I expect to sleep in shelters with some regularity; (b) I sleep on my side, which is much more comfortable to do on a TRest, and (c) I now qualify for "old" bones.

Rather than carry a full-length TRest and add another 4 ounces, I carry a Z-Rest sit pad at 2 ounces that I attach to my pack and can pull out to sit on when I stop. In camp I use this for my feet, although I usually need to put some clothing underneath the pad to keep it from sliding over the floor in the middle of the night.

10-10-2002, 02:50
Over the years I have tried them all and am still trying various options.....for the next hike coming up soon I will use an Ultralight 3/4 coupled with the 6-section of Z-rest that is the packframe on my GVP-4....and we will see how that does...
personally I am a big believer in stealth camping, stop at the shelter and grub down then pack up and go 2-3 miles further down the trail then take a left or right and get off the trail a 100 or 200 yards or when you find a pine grove that can supply the needles needed for padding and loft....this gives you more padding than you can ever carry and more insulation at the same time, cooking/eating at the shelter keeps the scraps there for the bear lovers and if you have to have a fire you have a fire ring so more scaring of land....anyway back to the pads, i like thermarest and yes my bones are old! have tried the sleep pad by Golite, the one that went with the fuzz and fur..not much difference between it and hard ground

10-10-2002, 08:20
Has anyone noticed that the listed weights of some of the thermarest mattresses have changed? The current online catalog has the following information:

1.0" Ultralite (2.6 R-value): 3/4 at 18 oz; full at 29 oz.
1.5" Guidelite (3.8 R-value): 3/4 at 22 oz; full at 32 oz.
1.5" Explorer (4.7 R-value): 3/4 at 22 oz; full at 34 oz.

I discovered this when I went to buy what I thought would be a 16 oz three-quarter length ultralite. When I saw the 18 oz weight on the package, I decided hold off on buying it and to do a little more research.

What I think the thermarest mattresses use to be listed as:

1.0" Ultralite: 3/4 at 16 oz; full at 24 oz.
1.5" Guidelite: 3/4 at 22 oz; full at 32 oz.
1.5" Explorer: 3/4 at 22 oz; full at 40 oz.

My take on this is that there is reason to take another look at mattress pads, especially since I am looking to my first cold weather season with a Hennessy Hammock. Does anyone have any ideas how to align R-values with temperature ratings? For instance, with a 25 degree Western Mountaineering Ultralite sleeping bag, what R-value mattress pad would complement it? What R-value would complement a 40 degree Western Mountaineering HighLite sleeping bag...etc?

For reference, Cascade Design publishes the following R-values in their on-line catalog:

2.0" Luxury Edition: 4.1 R-value
1.6" Camplite: 4.1 R-value
1.5" Guidelite: 3.8 R-value
1.0" Ultralite: 2.6 R-value
1.75" Standard: 5.8 R-value
2.0" Basecamp: 6.1 R-value
1.5" Explorer: 4.7 R-value

0.75" Z-Rest: 2.2 R-value
0.75" Ridge Rest Deluxe: 3.1 R-value
0.625" Ridge Rest: 2.6 R-value
0.44" Ling Rest: 1.9 R-value

Big Agnes also makes inflatable air mattresses and their on-line catalog list a temperature rating. (I believe that at one time their on-line catalog listed R-values and that they have switched to temperature ratings.) The Big Agnes catalog shows that their foam is cut most similar to the Camplite/Guidelite/Ultralite series from Cascade Designs. Big Agnes list the following information, but I don't know how accurate it is or how it was determined (I guess my own experience with a 1.5" Guidelite and other comments I have read about people getting cold with a 1.0" Ultralite makes me surpised by their ratings):

1.0": 25 degrees
1.5": 0 degrees
2.0": -15 degrees

What I found out last winter sleeping in a tent, was that you can get danged cold from the bottom side if you don't have enough insulation under you. For those of us who are very concerned with carry weight and pack-size, I believe it would be nice if we could match-up sleeping pads and sleeping bags with temperature ratings...which is what Big Agnes is doing with their products.

Any comments would be appreciated.


10-10-2002, 11:21
I can't answer the R-value vs temperature question exactly, but I can offer some experience. In the '70s, we considered a proper winter sleeping pad to be 1/2 inch thick closed cell solid foam. I don't know an R-value for such foam, but it should be significantly larger than a Z-rest or Ridge-rest. However, I always found this marginal for sleeping on snow and supplemented it with clothing under my body. Even so, checking the spot where I had slept the next morning showed that enough body heat had leaked through the pad to melt snow underneath and leave an ice patch the next morning. But I was reasonably comfortable this way. More recently I have been using a Thermarest 3/4 standard pad on top of 3/8 or 1/2 inch thick closed cell foam and sleep very warm. There is virtually no melting of the snow under my body. I have also recently tried a Mountain Hardwear High Mountain pad (R-value 6.75) and found that I melt snow below me. M.H. claims that this is a winter pad.

Note that just thickness doesn't tell you everything with self-inflators, or even closed cell pads. The self-inflators with "lite foam" or lots of air channels will not be as warm because air can circulate within the pad. Also, they need to be fully inflated (I blow them up hard by mouth) to achieve maximum insulation. Non-solid closed cell foam (like Z-rest and Ridge-rest) is not as warm as solid closed cell foam.

Hope this helps.

10-21-2002, 19:56
i switched from the ultralite to a ridgerest this year and was very pleased mainly due to the fact that im a restless sleeper and found with the thermarest i would wake up only half on the damn thing. i seem to stay on the rr better plus you can just throw it down anywhere. it also makes a pretty good framesheet if im going ultralite. no doubt the thermarest is more comfy if you can stay on it.

02-15-2004, 00:45
OK, let me clear up this R value thing. the R is for "rated" of course. The numbers correspond to inch thickness of fiberglass comparison. In other words, R-4.7 is equivalent to having something 1.5 in. thick but "Rated equivalent to 4.7 inches of fiberglass insulation. That's pretty warm...partner. So, they're basically comparing it to house insulation. I know because I helped engineer some of that stuff.

02-15-2004, 19:24
OK, let me clear up this R value thing. the R is for "rated" of course. The numbers correspond to inch thickness of fiberglass comparison. In other words, R-4.7 is equivalent to having something 1.5 in. thick but "Rated equivalent to 4.7 inches of fiberglass insulation. That's pretty warm...partner. So, they're basically comparing it to house insulation. I know because I helped engineer some of that stuff.

Here's a case of good marketing. R is a thermodynamic property. It stands for the resistance to heat flow, not thickness of fiberglass insulation (6 inches of fiberglass insulation is R-19). Think of it as a denominator. An R-value of 2 is 1/2 the resistance of something. When you double it to 4, that 1/4 the resistance. Now, if you put another 6 inches of insulation in your attic, that makes it R-38, which means you are changing the heat loss factor from 1/19 to 1/38.

02-15-2004, 19:33
I have a ul-asym and it holds my 250 just fine. Hennessy does have models rated up to 350 availible.
Ditto: Only 215 lbs, though.


02-18-2004, 18:20
I own three Therm-a-rests. The regular long and the 3/4. The 3/4 inflateable has gone the entire AT, the Maah Deh Heey and many other long hikes without leaks or problems. I also have the 3/4 ultra lite which I will be using for my AT hike this year. As always there is the give and take. I have two closed cell pads as well but find them much less comfortable even though quite light compared to the inflateables.

Did hammock use only resently become popular? I Section hiked the first time over 1999, 2000, and 2001 in the traditional sense (no slackpacking, no skipping). I must admit I did not encounter one single person using a hammock in that time frame and mileage.

Kozmic Zian
02-18-2004, 20:18
Yea......Mattresses. I've used both closed cell foam (z-rest) and Thermarest. I'll tell you there is nothing like lying down on a Thermarest. Immediately the warmth comes up to met you. It's hard to explain how and so fast. The Z rest sleeps cold and packs akwardly. You see zrest campers and they always got this big rubber thing swingin', man. The 3/4 ultra light weighs 16-18oz, and rolls to 4X10". I mean it fits in my pack beside the Sleeping Bag in the bottom compartment, The Sleeping Bag dosen't even know it's there. I'll pack the Thermarest for the extra comfort. Alot o' guys are talking about old bones, and I'm sure after you pass 50 or so it could make a little difference, but the biggest thing is, how much meat you got on yo' bones, Heavy guys sleep softer than 'boney' guys. So if you're and endomorph, you might be able to get by with a Z-rest. But, ectomorphs might like the Thermarests better. Now, in my case, I'm a pretty big guy, 5'11" 230, but I still prefer the warmer, more comfy blow-ups. There, again it's about choices....go to the outfitter, throw the two out on the floor and roll around. Another thing is length. I found that my ankles took a pounding on hard floors with the 3/4....so you may want to consider that also. You can always put your jacket under your feet, which I do. Rolling around can be a problem as stated earlier by another hiker. The Thermarest will 'pop out' from under you sometimes, if you get too far on one edge. Just remember to sleep centered. If you can't, you might want to consider a hard mattress. I swear, if you have to roll those things out-side your pack, makes you look like a rookie! Some guys use them for support inside the 'infurnal' frame packs. I say, keep it simple, get a 3/4 ultra-lite Thermarest. Drove one Thru in '96.KZ@

02-19-2004, 08:28
Therma rest. And take the patch kit.