Vapor Barrier Liners: Theory & Application

By Andrew Skurka

Occasionally during the FAQ portion of my slideshows, and frequently at the start of every winter, I receive questions about vapor barrier liners (VBL’s). The content and tone of these questions suggest a general misunderstanding of and slight mystery about them, so in this article I’ll attempt to offer a comprehensive review of VBL’s based on my understanding of and experience with them – basically, what they are, how they work, and when to use them.

I believe that VBL’s can be a critical and pivotal component of winter clothing and equipment systems—and, to a lesser degree, shoulder-season systems. Unfortunately, there is not much information available on VBL’s—an internet search returns information that is mostly outdated, incoherent rambling, or mistaken. My hope is that this article will result in (1) a greater understanding of VBL’s and (2) increased use of VBL’s by those who recreate outdoors in winter conditions, especially those who go on extended multi-day endeavors. This includes backpackers, snowshoers, skiers (Nordic, backcountry, and alpine), alpinists, ice climbers, mountaineers, and even ice fisherman and hunters.