Gearblog! - Waterproof Boot Liners

It's becoming increasingly difficult to find a walking boot of any sort without a Gore-Tex or other waterproof / breathable liner, something that's irksome to a lot of users, particularly in very hot weather, so it was interesting to come across a short treatise by Trail's gear tester Graham Thompson saying that 'the differences in comfort levels between a boot with a waterproof lining and a similar boot without a waterproof lining are negligible'.

Our Graham tested moisture vapour transmission levels of boot components, which were identical apart from a Gore-Tex membrane, in the lab at Leeds University, then backed that up with a field test in the Lakes.

In the latter, testers wore near identical Meindl boots, one with and one without a Gore-Tex membrane on either foot, and temperatures and humidity inside the two boots were measured.

Both tests showed that in temperatures between 10 C and 15 C, the readings inside the lined and unlined boots were actually 'almost identical' with no appreciable difference in comfort. Interestingly though, there were big differences in sweatiness between different testers, with levels of humidity varying between 60 and 95 per-cent depending on relative sweatiness.

Counter-intuitively, the sweatier testers appeared to benefit slightly from having a Gore-Tex liner, with marginally lower levels of humidity recorded in the waterproof-lined boot.

Thompson concludes, probably correctly, that the other materials used in a boot and its construction are actually more important than any wateproof liner with features like big rubber rands and heel and toe protectors rendering large areas of the boot none breathable.

So It's Myth?

We've always maintained that while Gore-Tex-lined footwear is fine in normal conditions, in very hot weather it's noticably less comfortable than non-Gore lined footwear.

In particular, fabric boots, which ought to be cooler in summer conditions, are actually subjectively just as hot as full leather ones - the issue we have with waterproof lined boots isn't about general use, but the way that approach shoes and lightweight boots with mesh panels that would otherwise work well in really hot conditions invariably end up with a waterproof liner that compromises their performance in the heat.

We'd love to see the test repeated in really hot conditions using a fabric boot with breathable mesh panels, somehow we suspect that the waterproof liner wouldn't do quite as well...

On top of that, we've also found that waterproof-lined boots take an age to dry out when water does get inside them, probably because once off the foot, there's no heat gradient to push water out through the lining.

So interesting stuff, but possibly not the full story - in very hot conditions, we'll still be steering clear of Gore-Tex and other waterproof liners. The problem isn't, as far as we can see, that waterproof boots don't work in normal British conditions, but that the sheer ubiquity of the things make it very hard to take advantage of the potential hot weather performance of fabric-based boots and shoes with mesh panels rendered useless by the linings.