Therm-a-rest does recommend that you store
any self-inflating pad with the integrated valve open. When they ship the pads they are
in a compressed state so when you purchase a new self inflating pad it’s recommended
that you open that valve and give the pad 24 hours, or whatever time you can give it,
open so that the foam can rebound a little bit and get to something closer to full inflation.
The self inflating design on these pads allows you to get where you’re going, get your
pad out of your pack or out of a stuff sack, open the valve and basically lay it in place.
You can flatten it out and you can hear right away air is beginning to draw into that valve
and that air is then inflating the open cell foam core on the interior of this pad. If
I’m backpacking I’ll lay it out, walk away, come back later and it’s pretty much
where it needs to be. That said, a self inflating pad will not fully inflate itself and if you
want that full firmness you’ll want to introduce just a puff or two of air into the sleeping
pad. In this case, a single puff of air was sufficient to get that to a full inflation.
To adjust the firmness, lay down on the pad, reach over your shoulder and open that valve
just slightly, let a little air to come out and the pressure of your body will sink into
that pad and if it’s as firm as you’d like it to be, close the valve and enjoy a
comfortable nights sleep.