We get a lot of questions about our self-inflating sleeping pads. How do they work? Do I have to blow them up at all? How should I store a self-inflating sleeping pad?

All great questions, so we’ve answered them here:

inflating sleeping padsPhoto by Lisa Paarvio

1. How it works.

A Therm-a-Rest self-inflating mattress is indeed a layer of open cell foam, enclosed in a sandwich of airtight fabric. The natural tendency for foams to rebound when compressed is what draws air into the mattress for “self-inflation”.  Forty-two years ago, Jim Lea, John Burroughs and Neil Anderson mocked this concept up on a wooden press the size of a large book and it worked.  The rest is history.

Lounging on a couple of sleeping padsPhoto by Lisa Paarvio

2. Getting the Most of It.

We choose our internal foams for, among other things, their light weight and memory”, meaning their tendency to bounce back after being compressed. When you first buy a mattress, it has likely been rolled for some time. To recalibrate the foam in a new mattress, lay it out and open the valve for at least 24 hours prior to your first use, letting it re-expand to its natural resting state. Then, somewhat paradoxically, it will “remember” being fully lofted the next time you roll it for a trip and you’ll get maximum self-inflation when you un-roll it.

inflating sleeping padPhoto by Bard Basberg

3. The “Myth-understanding”

Sorry, but a Therm-a-Rest self-inflating mattress really does need your help sometimes, but just a little. Though it depends greatly on the mattress (based on the type and thickness of the foam we use), once you open the valve, your mattress will begin to inflate – by itself. That’s the “self” part. However, to be completely transparent, you may indeed need to top off your mattress with a few breaths of air to achieve your desired firmness. For a softer sleep on a thicker mattress, you might not, but most people will puff a breath or two to firm things up.

deflating a self-inflating sleeping padPhoto by James Barkman

4. Storage

To keep getting maximum self-inflation, always store your mattress unrolled, with the valve open. Storing them under a bed, in a closet, behind always-open doors or flat on a shelf are all good suggestions. Just don’t store them rolled up with the valve closed if you want to get the most “self” out of your self-inflating Therm-a-Rest mattress.

So there you have it: some great tips on getting the most of your Therm-a-Rest self-inflating mattress. See you outside!

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Updated. Originally Published April 28, 2015.