15

It depends on the thickness of the mattress and the ground below it. With a very thick mattress and a level ground, it's the opposite: Less air is softer/more comfortable.** The thinner the mat or the less even the ground (e.g. roots), the bigger the chance that you "touch" the ground (i.e. only compressed foam in between) - usually that happens at your hip (...


14

Pads have several measurable characteristics that may be important for you when you make a decision: Weight. How much you carry is important if you actually carry it. Weights ranges from ~250g to several kilos. Don't forget to consider the repair kit if needed, the pump if you take one, ... Dimension folded. If you carry it outside your pack make sure it ...


13

Air Mattress Pros: Comfortable (Come in many varying thicknesses.) Warm (Some air mattresses are down-filled.) Compact (I have one air mattress that can pack down to fit inside a pop can.) Lighter (Not necessarily true for all air mattresses.) Cons: More Expensive More Maintenance (Can easily be punctured.) Some experience required (How firm do you make ...


13

Yes, the R-value will add of your different layers. If you wear layer A with R=5 and layer B with R=2.5, the overall insulation value will be R=7.5. To explain this a bit, we think of two layers or flat walls which interact only due to thermal conduction. This is just a model and in reality other effects will come in play. The Fourier Law for thermal ...


12

If you want to test a sleeping pad's insulation yourself at home, then the way to do that would be to try sleeping outside your house in and see how they work. That is worth doing because you might sleep differently from the next person. On the other hand, it seems like there is no simple way to retest for the R-value assigned by the manufacturer as that ...


11

Depends on the situation and therefore the gear you have along and the environment you are in. For example if you are on an alpine tour, you can do similar as we did this year in a bivouac: try to get in wind protected area (not so important in your case but even with a tent it changes your comfort) get a flat surface (heads up) lay your ropes directly ...


11

I have a self-inflating mat, and I think the foam serves three purposes. In order of importance: It sets the shape of the mat when inflated. Think of the foam as limiting how far the opposite walls of the mat can be in any one place. If you didn't have this, the mat would become more of a circular tube as it is inflated. For cushioning, the foam does ...


10

I think the reason for this difference in slipperiness is purely a factor of surface material. Most foam pads have a tacky surface finish. Inflatable pads, on the other hand, usually have a sturdy synthetic fabric as the surface. Fabric on fabric (sleeping bag on inflatable pad) will stick less than fabric on foam, unless the fabrics have been treated ...


9

For the characteristics of the pads you selected, here is what I can say: Weight Crucial when backpacking. 1lbs 1oz (740g) is on the heavy side, but still doable. 2.5 lbs (1140g) is enormous. If you put that on the outside of your pack, it could unbalance it, and pull you backward. Unless you put it at the bottom, but then you risk tearing your pad when ...


9

It is not clear whether you are motivated mainly by scientific curiosity or mainly by a desire to ensure comfort in the wild. My answer assumes the latter. This answer adds only one point to Charlie's excellent answer, and refutes one of your reservations to his answer. A stringent test as to whether your pad is good enough for all (or almost all) of the ...


8

My only thought is to use them as patching material for the other self-inflating pads your kitties will puncture. Cutting them to-size for inside an animal crate or other surface you want to protect.


8

You need the right balance of air pressure. Both too much and too little can reduce comfort. This can be seen by thinking about the limiting cases. With no air, you're directly on the ground. If you could put very high pressure into the mattress without it exploding, the mattress would itself be hard, and you're effectively back to being on hard ground. ...


7

My 2 Cents: Winter camping requires two pads, one inflatable and one foam. The reason for this is that not having any pad at all looses a lot of heat into the ground if you are camping on snow. Even the warmest bag will be uncomfortable without a pad camping on snow. While inflatable pads are really nice, they all eventually fail, particularly in the ...


6

Many manufacturers of inflatable sleeping pads sell repair kits. Duct tape could be used in an emergency, but I would only use it as a last resort as it will leave a residue on your sleeping pad when you get back home and want to repair it properly. Most kits will have something like the following items in them: Seam Grip Sealer & Adhesive Tenacious ...


6

Not exactly, if your sleeping pad gets wet and you lay your sleeping bag on top of it then your sleeping bag will get wet and that's not a good thing. Otherwise, your sleeping pad is preventing air from getting out, and that means its capable of keeping water out. On the other hand blowing into it will introduce moisture which can be a problem in cold ...


6

Extra air works if the reason it feels too hard is that you're compressing the filling (these mats have an open, springy foam inside). But of course there's a point where adding air makes it firmer even though the air moves so you're supported over a larger area. Just add with old-fashioned air mattresses, you need to optimise them for your own use. You can ...


5

Foam pad(s) for me! Because: inexpensive, different types can be combined, always ready, waterproof, lightweight. After years of trying just gave up on inflatables (or should we call them puncturables?). No matter how careful I was, they puncture, somehow. And the price! And yes, if you are trekking Everest (again, not) you will need both types ;) Now ...


5

This is an unsourced quote, I'm afraid, but perhaps relevant. Reflective foil is very effective, reducing radiated heat loss by 97%. That's almost all of the 5% we lose by radiation. In other words, IR reflection is useful only when you've almost eliminated conductive and convective heat loss.


5

In terms of sleeping, a sleeping pad performs two purposes. The first is to provide warmth and down is a good insulator. The Exped XP 9 LW has an R value of 8.00, a weight of 41.3 oz, a length of 77.6 in, width of 25.6 in, and thickness of 3.5 in. The ThermaRest Prolite Plus, a fairly high end self inflating pad has an R-Value of 3.4, a weight of 31 oz, a ...


5

It looks like there is not a consensus on what the minimum R value should be, but that the higher the R value the better. It will also depend on how you sleep and what your comfort level is. If it would be possible to borrow one to try it out before going I would suggest doing that. Its worth trying the pads out in advance where you won't freeze to death ...


5

Yes, they should be additive in this situation and its pretty commonly done. As long as the materials involved are dense solids in direct mutual contact,[9] R-values are additive; for example, the total R-value of an barrier composed of several layers of material is the sum of the R-values of the individual layers. Source Yes, the R-values of sleeping ...


4

I will start as everybody else... :P I'm a side sleeper too. I own a therm a rest 4 season sleeping and despite of being a nice mat for sleeping on snow (inside a tent of course) or soft grass, it's a bit too thin and I can get sore hips if sleeping on hard ground. My wife got a exped mat and because they inflate quite a few inches (her one goes around 3 ...


4

I'm a side sleeper as well, and I've found that the gaps in my x-frame help give my hips and shoulders a little extra room when I'm on my side:


4

According to wikipedia2 In calculating the R-value of a multi-layered installation, the R-values of the individual layers are added. I would imagine a slight diminishing return as the r-value is a laboratory measurement in ideal condition which is not quite the same as on the field (variable temperatures, moisture, air movement, etc.).


4

I don't know how robust the waterproof bottom of your bivy bag is, but with the bivy bags I know (which are predominantly some kind of mountaineering emergency equipment) I would not want to put the sleeping pad into them. The reason is simply, that bivy bags are designed to give a good weather insulation (primarily by being waterproof and windproof) while ...


4

The foam inside the mat prevents heat loss through convection which would be the case with the air if there was nothing to prevent it moving. This forms part of the open cell vs closed cell argument for sleeping mats.


4

At the risk of sounding like a grumpy old person it seems like EVERYTHING is slipperier than it used to be. I'm not sure if new stuff starts slippery and gets less so, or if things are now made more slippery. But I have bought a new tent, new sleeping pad and new sleeping bags this year and between them - I had better set up on 100& level ground. I used ...


4

Fully inflatable mattresses don't provide a great deal of insulation from the ground and tend to be fairly heavy plus they take a bit of effort to inflate and deflate which can become a nuisance if you are moving camp every day, especially in bad weather. A closed cell foam pad is inexpensive, rugged and provides good insulation for light weight. Their ...


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