Camping Tips: The Sleeping Pad

[mesha]

The importance of a sleeping pad
When sleeping heat is lost to the ground very rapidly. Sleeping pads are there to slow down the heat loss. Even though you have a sleeping bag your body crushes the insulation making it less effective. The job of a sleeping pad is to keep you off of the ground. The further away from the ground the better. Pads stop conductive (the fastest form of heat transfer) heat loss from happening.


Types of sleeping pads

Closed cell - Dense foam filled with little air bubbles.

Examples:

Open cell - Low density foam mainly designed for comfort

Examples:

Air - Tubes that you manually fill with air.

Examples:

Air bed - The big thick kind that are made to mimic beds at home

Examples:

Self inflating - An air pad with open cell foam inside. The valve is opened and the foam expands and draws air into the pad.

Examples:

Closed cell
Pros
- Light weight
- Does not absorb water
- Really cheap
- Nearly indestructible
- Easy to customize

Cons
- Bulky
- Not as comfortable

Open cell
Pros
- Lightweight
- Comfortable if thick
- Mid range in price
- Durable

Cons
- Compresses underbody similar to sleeping bag insulation
- Absorbs a lot of water
- Breaks down over time
- Bulky

Air
Pros
- Light
- Comfortable
- Very compressible
- Can be very thick for low weight and pack volume
- Some have insulation in tubes for 4 season warmth
- Water proof

Cons
- Can be expensive
- Not as durable
- No insulation if punctured
- Convective heat loss can occur
- Requires effort to inflate

Air Bed
Pros
- Cheap
- Very thick
- Home bed “feeling”
- Water proof

Cons
- Least durable of them all
- Cheap construction
- Heavy
- Requires a lot of volume to inflate

Self Inflating
Pros
- Easy to inflate
- Low bulk
- High warmth to weight ratio
- Some insulation if punctured
- Fairly durable
- Water proof

Cons
- Expensive
- Can be punctured
- Some types can be bulky

Warmth ratings
- Sleeping pads are rated using R-value. The “R” is for resistance to heat transfer.
- R-values generally rate from 1 to 12
- A thin summer rated pad will have a lower number. Winter pads will have a higher number.
- Thicker generally means higher R-value when compared to similar designed pad.
- All insulation is designed to slow heat transfer. The slower the heat transfers the warmer you will be.

Size of pad
Length
On a spec sheet
- A short will be 48”
- A women will be 66”
- A regular will be 72”
- A long will be 78”

Width
On a spec sheet
- A regular will be 20”
- A large will be 25”-28”
- An Xl will be 28”-30”

Considerations
· Pads can be combined to achieve the wanted R-value. Many people will combine a closed cell foam pad and an air or self-inflating pad. While it seems like you should put the closed cell pad under the air pad it is actually better to put the closed cell pad on top of the air pad. It will be warmer that way.
· If you have an inflating pad of any type you can take a repair kit with you.
· Remember to properly store your pads. Inflatable and self-inflating pads should be stored unrolled with the valve open. Under your bed is a really good place to store them. Closed cell pads can be stored rolled up, but they will “remember” the shape they are stored in and be harder to unroll when you get to can and resist laying flat. All camping gear should be stored out of direct sunlight. Open cell pads are particularly susceptible to UV damage. Cats will claw your pad.
· You can make your sleeping experience more comfortable by wading up a jacket or similar and placing it above or below the pressure point. If your pressure point is your hip put the wad above your hip at the waist. It will relieve a lot of the pressure on your hips. If the pressure is on your tailbone put the wad in the small of your back.

 

[sixstringsteve]

Many people will combine a closed cell foam pad and an air or self-inflating pad. While it seems like you should put the closed cell pad under the air pad it is actually better to put the closed cell pad on top of the air pad. It will be warmer that way.

Interesting, I did not know this. Thanks for putting this resource together.

 

[Tonkaman]

Great write up! Thank you

 

[Kevin B.]

Find the picture you want to use - right click on it, choose properties, and copy the URL for the picture itself. Put the cursor where you want the picture in your post, hit the "insert image" button in the toolbar above the edit window, and paste the image URL. Hit enter.

My biggest gripe with air mattresses is the space they take up when packing. Between the mattress and the pump, they're huge, and they take longer than they should to set up and take down. I've gone to an air pad when I'm not using my hammock, but you've got a good point about the lack of insulation. I was planning on rolling out a wool blanket underneath it at FYTO, you think I should put the blanket over it?

 

[Unimog]

I've never used many closed cell pads because my skinny hips need more padding. Can someone comment on the waffle style pads vs flat? Also, how much better are the reflective coated models?

 

[sixstringsteve]

Can someone comment on the waffle style pads vs flat? Also, how much better are the reflective coated models?

I'm no Davy, and I look forward to his response, but here's my experience. I have a closed cell waffle pad (Therm-a-rest Z-lite sol). I bought it as a second pad for winter camping (to use in conjunction with my air pad). It's the accordion-style waffle with reflective coating. The reflective coating is an extra $10, and it moves the R-value from 2.2 (non-reflective) to 2.6 (reflective). Not a HUGE difference really, but it's something, and the reflective coating doesn't weigh any more. I like how light and sturdy this pad is, but I'm a side sleeper and it doesn't have near the padding/comfort that I need. I can't sleep on just one of these. In conjunction with an air pad, it should really up my insulation in the snow.


On the therm-a-rest air mattresses, the reflective coating makes a big difference.

Neo Air X-lite: 3.2 R value, 12.2 oz
Neo Air X-Therm (same pad, just with reflective material): 5.7 R value, 15 oz

I sleep cold, so I figured the extra 2.5 R rating was worth the extra 3 oz of weight. It really is a toasty pad; I can usually feel the heat radiating back toward my body.

 

[mesha]

Find the picture you want to use - right click on it, choose properties, and copy the URL for the picture itself. Put the cursor where you want the picture in your post, hit the "insert image" button in the toolbar above the edit window, and paste the image URL. Hit enter.

My biggest gripe with air mattresses is the space they take up when packing. Between the mattress and the pump, they're huge, and they take longer than they should to set up and take down. I've gone to an air pad when I'm not using my hammock, but you've got a good point about the lack of insulation. I was planning on rolling out a wool blanket underneath it at FYTO, you think I should put the blanket over it?

The reason the insulation on top works better is because the closed cell pad keeps your body heat from going past that layer and into the air pad. Air is a great insulator, but with the closed cell (or wool blanket) on the bottom you will be heating up the air between you and the closed cell pad before heat loss is slowed down (convection loss). Also, It makes a really, really big difference to have your air pad more inflated. The more inflated, the warmer you will be. It can be less comfortable, but warmer because your body heat must move through more "good" insulating air before it is cooled down by the "bad" insulating ground. In a pad like my Exped synmat we are talking a few full points in R-value.

I've never used many closed cell pads because my skinny hips need more padding. Can someone comment on the waffle style pads vs flat? Also, how much better are the reflective coated models?

The waffle style pads are a little better than the flat style closed cell. The closed cell pads with a waffle style pattern like the z-rest or ridge rest are also a little better. They will never be as comfortable as an air pad or self inflating pad. You should give the wad thing I talked about a try. It is very helpful. Another option is to cut a circle out of a thick open cell foam pad and use it just under your hips. that way you can have the cushion where you need it without the weight of an extra full length pad. The sleeping situation is where many people choose to carry extra weight because it is very hard to hike after a bad nights sleep.

The reflective models work. They stop reflective heat loss from happening. While reflective heat loss is not the main form of heat loss it is definitely a contributing factor. When given the choice I would choose a reflective pad. In the summer if it is too warm you can always flip it over and sleep on the non reflective side to keep from over heating. In an air pad the reflective side makes a bigger difference than it does in a closed cell because air is a good insulator and your main enemy is convection. the reflective layer "bounces" your body heat back toward you, thus, less heat is in the air insulation of the air pad so you get less thermal movement. WIth a closed cell pad the main enemy is conduction, the reflective layer does not slow that down as much.

 

[Kevin B.]

I started using a reflective tarp as a footprint under my little tent last summer. I made highly scientific observations noticed a little more condensation in the tent in the mornings, so I think it helps a little.

 

[Herzog]

I have an old military/air-force air mattress that has a bag on the end that you "fluff" up then roll to air up the mattress. It's actually very quick and extremely durable. I've used it for several lone camping trips. The downside is that the rubber is kinda thick so when it's rolled up it can be a little heavy, but it's also pretty small when rolled up. No need to carry a pump or anything. It is also pretty much the only air mattress I've ever had that doesn't slowly leak down or cause condensation on your body at night.

I'll get some photos of it tonight.

 

[sixstringsteve]

what about condensation inside your pad? My pad takes about 25 full breaths to fill up, and I'm sure I get a lot of condensation in it. Am I permanently damaging my pad by allowing so much condensation in it? Also How should I store my pad when I'm done with it?

 

[mesha]

I have an old military/air-force air mattress that has a bag on the end that you "fluff" up then roll to air up the mattress. It's actually very quick and extremely durable. I've used it for several lone camping trips. The downside is that the rubber is kinda thick so when it's rolled up it can be a little heavy, but it's also pretty small when rolled up. No need to carry a pump or anything. It is also pretty much the only air mattress I've ever had that doesn't slowly leak down or cause condensation on your body at night.

I'll get some photos of it tonight.

Most of the major manufacturers or air pads offer an inflator bag to do the very same thing. The inflator bag I use for my Exped synmat weighs 3 ounces and doubles as a backpack liner/ dry sack. Sounds like they got the idea from the military. It is MUCH easier than blowing up my pad.

what about condensation inside your pad? My pad takes about 25 full breaths to fill up, and I'm sure I get a lot of condensation in it. Am I permanently damaging my pad by allowing so much condensation in it? Also How should I store my pad when I'm done with it?

Condensation will form in your pad. No matter what you do. How moist the air is when you put it in and how much of a temp difference you see over night will determine how much. As far as permanently damaging the pad that is up for debate. Mildew can occur inside the pad, but the foam inside is mildew resistant. Also, how would anyone living in a wet climate have a pad that didn't get moldy inside. We live in Utah, I wouldn't worry about ruining your pad. I would worry about the moisture making your pad heavier and hurting the insulating properties. Especially on long extended cold trips. In greenland I dumped moisture out of my air pad every morning. I had some success with filtering my breath through a bandana as I blew it up. That helped significantly, but didn't stop it. Moisture is not good for your pad, but if you store it properly then it shouldn't be a problem.

Speaking of storing. Open up the valve on your pad during storage so some air movement can occur. Leave the valve open all the time. I like to hang my pad with the valve facing down so it can drain if possible. Storing the pad rolled up might save some space in your closet, but it is not good for your pad. The foam will break down over time, just like in a sleeping bag that is stored rolled up.

 

[sixstringsteve]

Do most air pads have foam in them? Does my x-therm pad have foam in it?

 

[mesha]

Do most air pads have foam in them? Does my x-therm pad have foam in it?

Only some air pads have filling. Your x-therm does not have foam in it. It has stuff that looks like a dryer sheet. It will not be ruined much be being stored rolled up. I would still leave it unrolled and with the valve open.

 

[Unimog]

How many of you fill your cold weather pads with an inflator to avoid condensation? The pouch for my xtherm doubles as a pump bag type thing. I try to fill it using that and then top off by breath. Before I had the xtherm, I had one of those long inflator bags - don't remember the name.

 

[mesha]

I used to just blow them up, but then I took notice of how much condensation I was putting in it. I use a bag now to inflate them. Thermarest even has a little battery powered pump for the Neoair series.

 

[Rock Taco]

I have noticed a few sleeping bag manufactures making them with ways to attach or hold on to sleeping pads on the exterior of the bag. Would there be any advantage to placing your pad inside you sleeping bag since the bottom of your bag is relatively useless being compacted with your body weight?

 

[moab_cj5]

I usually put my pad on top of a cot. Sometimes i put the pad in my bag so it doesn't move around. I haven't noticed any additional warmth inside the bag vs outside, but I am sure others will have more informed input than me.

 

[jackjoh]

I used a closed cell ensolite pad with a ground cloth of some kind. It also helped in the back of the Scout or on a cot for insulation. Not meant for comfort but could always make a hip hole in sand, snow, or dirt with leaves.

 

[spencevans]

One thing that was missed and is worth mentioning is weight capacity. The air pads will be able to fat guys like myself off the ground more easily. I use a Exped Downmat XL and it keeps me off the ground. The filled air pads typically have the highest R-value of all the pads. I have also noticed my Downmat is much more durable than I expected. The life of the Downmat will be atleast 20 years. I have owned two for about 10 years and they are still going strong. I do still use 3" open cell pads from Smith's Market Place but I need about 6" of padding to keep my 300lb fat but off the ground. Over the past 30 years of using open cell pads I have noticed they are pretty worthless after 6-7 years.

 

[DAA]

I've been using the same open cell pad for more than ten years now. Still going strong - used it on some below zero nights last weekend.

I almost always use it on a cot though. And I use the relatively cheap cots. They typically only last me about three years.

- DAA