How Do Self Inflating Sleeping Pads Work

Self-inflating sleeping pads are without a doubt the most convenient gear for outdoor enthusiasts. Even though they’re a bit bulkier compared to air sleeping pads if you have enough space on your backpack and don’t mind the extra load, in contrast to normal sleeping pads they’re more insulated and comfortable.

Quick Note: Some people prefer calling them sleeping mats, but in case you wonder, there is no difference between sleeping pads and sleeping mats, they are exactly the same thing.


How Self-Inflating Sleeping Mats Work

Between the two layers of a self-inflating sleeping pad, there is a chemical called PU (Polyurethane) which is a kind of foam, and this foam has open-cells that release the air inside when the pad is rolled up gets compressed. Therefore, when the pad is rolled up and the valve is closed it creates a vacuum effect. So due to this vacuum effect, when you open the valve the pad draws the air back in and starts to expand.

Although it depends on the sleeping pad, it takes 3 to 10 minutes to suck all the air in. But almost in every sleeping pad, you need to blow one or two puffs by yourself to fully inflate the sleeping pad.

There also other types of sleeping pads as well, and each one is better on different features.


Are Self Inflating Sleeping Pads Comfortable

sleeping pad pressure mapping

It actually depends on the person, some people prefer air pads (since they’re thicker) some people prefer self-inflating sleeping pads. But the general idea is self-inflating sleeping pads are more comfortable.

But if you’re a side sleeper you might feel more comfortable with an air pad. Since side sleepers lay on their side, more pressure is being made to the sleeping pad, as a result, they are more likely to feel the ground. For side sleepers, I recommend looking for a pad that is at least 3″ thick. If you have a bad back, check out my article where I gathered the best sleeping pads for bad backs.

Unlike solid sleeping pads, with self-inflated and air sleeping pads you can alter the firmness of the sleeping pad. You can simply release the air out to make it softer and blow some air to make it more firm.

If you inflate your pad with your mouth most of the time, I recommend getting a pump suck. Because blowing with your mouth is bad for two reasons:

  • The air you blow with your mouth is warm, and during the night when it’s cold, warm air you blow loses its volume when it gets colder which makes the pad gets softer
  • Your breath contains moisture that could gather in your pad and eventually it may cause mold.

So if you inflate your pad with your mouth a lot, then consider purchasing a pump sack.


How to Store Self Inflating Sleeping Pads

The best way to store self-inflating sleeping pads is to leave the pad semi-inflated with the valve open.

Storing them rolled down is bad because most of the self-inflating sleeping pads remember the shape it holds most often, also keeping the valve open is good since it creates air circulation inside the pad.

Lastly, the moisture is the cancer of sleeping pads, it can cause mold which eventually ends up screwing your sleeping pad, therefore, make sure to keep your sleeping pad in a dry place.


How to Repair a Self-Inflating Sleeping Pad

The sleeping pad is the gear that touches the ground every time we use it and it’s made of thin fabric, therefore it would be unreasonable to expect them not to get damaged. But that is not a big problem as you might think, most of the sleeping pads come with a repair kit. But to ensure using repair kits as less as possible it’s always good to clear out the sticks and rocks off the place where you will lay down your sleeping pad.

But let’s say somehow your sleeping pad is torn off. If the rip is big then it’s easy to find it and repair it, but if the rip is small it might be a little bit overwhelming (in that case, you’ll probably discover the sleeping pad’s leakage when you wake up and see there remains almost no air at all).

If the rip is big, and easy to discover you can just fix it in 5 steps:

  1. Discover the ripped place
  2. Put the textile glue on the ripped surface
  3. Inflate the pad just a little bit so two ripped sides don’t get glued together and wait for 5 to 10 minutes
  4. After the glue is cured put the patch that comes with the repair kit on the ripped place
  5. Let it sit for 8 – 10 hours before you sleep on it

If the rip is small and hard to discover you can just repair it in 6 steps:

  1. Fully inflate the sleeping pad
  2. Mix soap and water and put it on the sleeping pad until you see some bubbles
  3. Discover the rip by looking where bubbles are coming from
  4. Put the textile glue on the ripped surface let it cure (until it’s no longer tacky) for 5 to 10 minutes
  5. Repeat the fourth step until you have 3 layers
  6. Let it sit for 8 – 10 hours before you sleep on it

If your sleeping pad is small enough you can also use this easy method to find the rip:
Fill a bathtub or another big tank with water and dip the sleeping pad into the water. And then find where the bubbles are coming from, and there you go, you found the leakage.


Sleeping Pad Valve Replacement

Your sleeping pad’s valve might be squashed, broken, or damaged, and it might not be working properly nay it might not be working at all. But that doesn’t necessarily mean that you should throw it away and get a new one.

Most of the sleeping pad valves can be bought separately in case you need to change it. Most of the replacement kits contain a valve and a glue.

You might think it’s a hard thing to do but actually the replacement process is very easy.

So if you have a broken valve, you can replace the valve in 8 steps after buying the replacement kit:

  1. Open the valve as far as you can
  2. Grab the valve cap at the base with a pair of pliers
  3. Pull the valve away from the pad while twisting and pulling the valve straight
  4. Clean the valve seat after you remove the broken valve
  5. Put glue around the perimeter of barbed valve end
  6. Push and twist the valve into the pad until its fully seated
  7. Clean the remaining glue
  8. Inflate your pad and let it sit for at least 10 hours

Here is a Therm-a-Rest’s video of Valve Replacement Tutorial:


How to Clean a Self Inflated Sleeping Pad

Cleaning your sleeping pad is highly important for its longevity but you need to do it in a rightful way or you might end up screwing it up.

When cleaning your sleeping pad:

  • Never use a washing machine
  • Make sure to use a non-detergent soap
  • During the cleaning process always keep the valves closed
  • If you have sap on your pad you can use an alcohol wipe to remove it.
  • Before you store it, make sure to dry it well with the valves open

What Is the R Value on Sleeping Pads

If you’ve ever bought a sleeping pad or thought of buying one, you probably came across with the R-Value, the R-Value is without a doubt the most important factor for deciding what kind of sleeping pad you need.

Although it seems like a hard technical term, it’s actually very simple:

Quick Answer: The R-Value is a measure of how warm a sleeping pad is

And for those geeks who seek the technical explanation, R-Value is a measure of how well a two-dimensional barrier resists the conductive flow of heat (in our case the two-dimensional barrier is the sleeping pad, but the term of R-Value is used in every industry where you need insulation, such as building walls, windows, etc.)

Returning to sleeping pads, as you might have guessed the higher the R-Value the more insulated the sleeping pad is. This measure is highly important because it gives you the ability to compare two tents’ insulation in a technical manner.

Why Is R-Value Important for Sleeping Pads

First thing you need to know, “the heat flows from hot to cold” in the universe we live in, so in our case, you are the “hot” and the ground is the “cold”. Therefore, the cold ground sucks the heat away from your body, and the only thing that protects you from the ground is your sleeping pad.

If you only go camping in summer where it,s 70°F-80°F then the R-Value doesn’t really important for you. But if you go camping in relatively cold weather, the R-Value must be your first priority.

What Is a Good R-Value for a Sleeping Pad

Man carrying a backpack sleeping pad vs air mattress

The sleeping pad that offers the highest R-Value is the best for keeping you away from the cold but it might not be the optimum one for you, because, as R-value increases, the weight and packaged size of the sleeping bag also increases.

If you’re into cold weather camping, I’ve created a solid buying guide of best cold weather sleeping pads.

It really depends on at what temperature you usually go camping. Below I created a table to show R-value / Temperature rating correlation.

By using the table, you can decide the minimum R-Value that you should go for.

R-Value to Temperature for Sleeping Pads

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