Ground Insulation

[Mally]

-17!!!!! I thought -10 was bad enough!
A couple of years ago I improvised a vapour barrier over polypropylene thermals at -4. Very uncomfortable but no problems with the cold.
I think it would be suited to colder temperatures.

[featherstick]

Two-thirds of your bedding underneath you, one third on top.

[ForgeCorvus]

Could someone explain this whole Vapour Barrier thing please?

[grenfell]

Glorified name for a groundsheet?
Most of my camping is when re-enacting and I use a "mattress " made of a few layers of felt carpet underlay covered in cotton sheeting and I've slept out in sub zero temperatures on a number of occasions. The major disadvantage though is bulk , no good for hiking.

[Yorkshire Andy]

No its a liner like (as in like a silk sleeping bag liner) but waterproof the intention is to prevent your body's moisture from entering the sleeping bag's insulation and making it damp which reduces its loft and its insulation property's


see point 6


http://www.helsport.no/en/SERVICE/Quest ... g_bags_Q_A

[grenfell]

Ah thanks for the clarification Andy.
Going back a couple of decades a few friends and myself were camping in Hampshire and the weather was lovely and warm so we decided to just sleep outside. Unfortunately it rained at one point in the night so we had to make a run for the van. The next night was just as warm so we decided to sleep out again. However , this time one of my friend's decided he'd be prepared and wrapped his sleeping bag in bin bags. It didn't rain that night but he still woke up soaking wet

[ForgeCorvus]

Ah, so you sleep in a plastic bag and wring yourself out in the morning?

Sounds 'wonderful'

[Yorkshire Andy]

Ah, so you sleep in a plastic bag and wring yourself out in the morning?

Sounds 'wonderful'

thats the one which is why a base layer set is handy to mop up the damp.....


Never been in cold enough conditions to even think about doing it........

but the goretex bag cover gets uses a lot to stop condensation in the tent from wetting my bag... Because you always get one that is cold and doesn't like leaving the vents wide open

I paid 30 quid for mine in York market (it was unused)

http://www.thearmystore.co.uk/acatalog/ ... rplus.html

[Mally]

A vapour barrier system. It can be clothing or a bag. Mountaineers use the system in extreme cold. The idea is that you do sweat but eventually, as your temperature and the moisture increase, you create your own micro climate. When the humidity gets to a certain point you also stop sweating further. Clothing is supposee to be worn next to the skin with other clothing over the top for the greatest benefit but this is very uncomfortable. It is better used over polypropylene thermal underwear.