Should You Blow Into Your Sleeping Pad?

Have you ever topped off your sleeping pad with a breath of fresh air? The directions recommend not blowing into your sleeping pad, but I definitely have.

My sleeping pad was fine in the short term, but was there unseen longterm damage? Just how bad is the moisture my breath, for my sleeping pad? What kind of disaster did I create for myself because I wanted to top off my sleeping pad?

Should You Blow Into Your Sleeping Pad?

When I first started backpacking I had a hard time believing water vapor could cause damage to my sleeping pad. Of course, I heard the rumors that you should only use a pump sack inflator, but I didn’t believe them.

I had been blowing into my pads for decades without any major problems. Sleeping pad longevity and hygiene never even crossed my mind.

I decided to give Thermarest a call to ask if I could blow up my sleeping pad. Surprisingly, they said it wasn’t a big deal. It was fine to blow up my pad by mouth and there shouldn’t be noticeable damage to the pad.

Why Are People Afraid to Blow Up Their Sleeping Pad By Mouth?

There are two main reasons why backpackers don’t like blowing into their sleeping pad. They think that the water vapor in your breath will cause mold buildup. You might also deal with freezing in the winter and condensation the summer.

These seem like very legitimate concerns, but they’ve never caused much of a problem for me. But what about all the hidden mold on the inside of my pad?

Yes, water vapor will penetrate the material in your pad to some degree and bacteria/mold will grow. Is this a critical problem? No of course not! It would take a very long time for bacteria/mold to damage your pad. Your pad isn’t going to last long enough for this to cause any major problems.

I can’t guarantee there’s no mold in your pad, but check out the video below for a look inside a well-used sleeping pad. There might be a little mold around the seems, but other than that nothing.

A Few other Concerns

To me, it just makes sense to minimize the water vapor in my pad so I always use an inflatable stuff sack pump. That doesn’t mean I don’t top it off with a few puffs of fresh air.

That being said, not all pads are created equal and some climates will be worse than others. People that live in hot arid climates don’t really have to deal with mold. It all depends on where you live and how much moisture is getting into the sleeping pad.

The least harm will be done to basic uninsulated air pads. Throw in some foam or down and you might run into a little bit of mold growth. This is less of a safety issue and more of a delamination problem when mold compromises the glue.

If you start to notice mold just continue to use the pad with an air bag or inflator to limit further moisture. After a few years just replace the pad and call it a day.