In the outdoors, unexpected situations can arise at any moment, and few things are worse than being unable to get a good night's sleep after a full day of hiking or alpine exploration. In a previous article, we discussed how owning multiple sleeping pads serves as a valuable safeguard against exactly this kind of scenario. However, inflatable sleeping pads always carry a degree of risk. After all, no one wants to crawl out of a warm sleeping bag at minus 20°C on a snow-covered mountain to patch an air pad. But if you pair your inflatable with a foam pad — or carry one as a backup — you can handle most emergency situations with confidence.
Foam Pads and Egg Crate Pads
Because closed-cell foam is used, the durability of a foam sleeping pad is largely determined by the density of the raw material. Foam pads are not easily cut or torn, and even if damage does occur, the pad remains functional. As long as the damage is not a large, open gash, performance is virtually unchanged. This is exactly why you so often see extreme alpine climbers and expedition teams in harsh environments with a foam pad strapped to the outside of their packs.
To put this to the test, we conducted an experiment on Mountain Spring's egg crate pads, deliberately inflicting varying degrees of damage — and even exaggerating the severity — to measure the actual impact on R-value.
Below is the test video documenting the post-puncture results (available on Bilibili):