Tyvek is somewhat breathable, more like long-term migration, sort of like the membrane in an egg shell. That's what makes it so good for wrapping houses. When used as a ground cloth on wet ground, you will probably have a damp spot in your sleeping bag where you applied pressure while sleeping. It falls somewhere between the old canvas ground cloths and black plastic sheeting. The best part is a Tyvek ground cloth will weigh less than an ounce which means you could take a spare in case the old one gets too muddy to contend with. Except for the noise in the wind, it would make a suitable tarp tent.
Jim Foreman
Subject: [ultralightbiking] Tyvek breathability
I use tyvek for my ground cloth under my bag when using a silnylon
tarp. I have the kite tyvek that's not as thick or noisy as the
house wrap. I'm thinking of making a bigger ground cloth with a
joined section at my feet when I need the extra warmth and also for a
little more water protection under the tarp if it's windy, I know
it's not water -proof-. This idea got me to thinking of sizing the
material large enough to wrap over the whole bag, leaving the down
wind side open to breathe. Or, if it's really cold maybe wrapping my
bag in it. I know Tyvek does breathe, but do any of you know if it
would breathe well enough to avoid condensation in this application?
I'm doubtful. On clear nights it would also work well to protect the
bag from dew. I probably should just make one with water proof
breathable fabric but the Tyvek would sure be quick and easy.
Gary
Having problems with message search?
Fill out this form to ensure your group is one of the first to be migrated to the new message search system.
Offline 
Send Email