Bivi bag question

[dirty ben]

What is the preferred method of using a sleep mat and bivi bag together,whenever i use mine i place my mat inside but i have read that it is better to keep the mat outside to keep humidity down,going out wild camping on dartmoor this weekend and im tempted to place a gas fire in the bivi with me as the forecast is pretty chilly

 

[Shewie]

With it inside you won't roll off in the middle of the night, with it outside there's a good chance you will.

The rest of the bag will breath so don't worry about condensation, you might get a bit on your mat but it's nothing to worry about for the sake of a weekend.

 

[Jinsin456]

It really depends on you, personally I keep the mat outside the bag but I tend to roll a lot and the mat would probably end up on top of me! On the other hand it means you can roll off the mat but mine has small baffles that surprisingly keep you on. I think the sleep mat inside the bivi suits hooped bivis more as they can't move around so the mat stays in place.

All down to your own preference though mate, experiment and see what suits you.

As for keeping warm, make sure you are well fed and hydrated and have been to the toilet before you go to bed and you should be okay, failing that boil some water and put a nalgene / issue water bottle in a pouch and use it as a hot water bottle

 

[SimonM]

I always put my mat inside the bivvy bag with me as it stops me rolling off and getting cold in the night.

I've done this with issue bivvy bags and, more recently, hooped with no ill effects.

Simon

 

[bilmo-p5]

I have the mat outside the bivvybag and frequently roll off it but I find it easier to roll back onto it than sort it all out when the mat is on top of / wrapped around me inside the bag.

 

[sandbag47]

inside

 

[Chiseller]

I've slept in several bags , from nasty issue ones to the at the time latest gas permeable goretex, in woods , mountain, Moor and garden. A mat inside wont make a difference that's notable. It's more down to how your body temp is due to prior activity and how you've eaten , drank etc.
An inflatable mat can help contribute to condensation as its warmer air if you blow it up.
If its an expensive bag you may want to keep the mat outside the bag. I'd be more concerned with water ingress if your not using a tarp / basha for cover ? Goretex is not much good when exposed to driving rain in strong wind. Experience......

 

[Chiseller]

I've slept in several bags , from nasty issue ones to the at the time latest gas permeable goretex, in woods , mountain, Moor and garden. A mat inside wont make a difference that's notable. It's more down to how your body temp is due to prior activity and how you've eaten , drank etc.
An inflatable mat can help contribute to condensation as its warmer air if you blow it up.
If its an expensive bag you may want to keep the mat outside the bag. I'd be more concerned with water ingress if your not using a tarp / basha for cover ? Goretex is not much good when exposed to driving rain in strong wind. Experience......

 

[sandbender]

What is the preferred method of using a sleep mat and bivi bag together,whenever i use mine i place my mat inside but i have read that it is better to keep the mat outside to keep humidity down,going out wild camping on dartmoor this weekend and im tempted to place a gas fire in the bivi with me as the forecast is pretty chilly

Inside, to prevent slippage during the night. I never have a problem with humidity but my bivie bag has a large diagonal opening and it is usually always unzipped.

I have used a sigg bottle as a hot water bottle, nice and toasty.

 

[dirty ben]

My bivi is a army bag and i use an exped 7.5 sleep mat with a snugpak chrysalis bag,going to be taking my softie jacket and trousers as back up if it gets too cold and try not to pull the bivi hood over my head which i have done before resulting in condensation on a previous trip

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[lannyman8]

i normaly use mine outside unless im on a bad slope then its inside as the slipping of is not so bad, as said above....

ref keeping warm at night, now this might sound weard maybe, but get down to your underwear, a maximum of socks and boxers, unless its really cold then a t/shirt on too, but thats it, keep your spare kit, t/shirt, trousers etc inside your bivi bag and use them as a pillow or lay on them, then when you wake up they are warm to get into in the morning...

when you first get into bed its cold for 5 mins untill your body heat warms it all up, but i do it every time and never have any problems...

hope this helps a bit...

regards.

chris.

 

[Bigfoot]

Depends on the weather conditions but if you prefer to have your mat outside and not keep slipping off, try running a zigzag bead of bathroom sealant down one side of the mat (test a bit first to make sure no chemical reaction ) and you will find it provides enough traction to grip your bag. In extremely cold weather the sealant may give up the ghost however.

 

[dirty ben]

Thanks guys for the replies,top notch as always.probably take the tiger paws plus bivi on this trip

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[JAG009]

I leave my rollmat on the outside of the bivi bag ,and to stop yourself rolling off it put yor boots to the side of you or something you will feel if you roll over to far


Jason

 

[Shots8]

Gas Fire inside a Bivvi? Surely not Dirty Ben, you may need to change your name to blisteredben! If using a bivvi remember the different materials have their ways of working and thus advantages and disadvantages-gore-tex does not mean dry per se, you still need the differential to achieve maximum design breathability.

 

[greenwood]

I use my roll out side, you can try this; when you make your night time brew, make extra boiling water and put it in your bottle and place it in your sleeping bag as a hot water bottle between your legs or feet this will help in the morning for a brew too as the water will be slightly warmer so boil a bit quicker.
When you go to bed change your socks as they always soak up moisture, so change them this will make you feel very warm, i always put on thermals before bed as this always makes me feel warmer as well.

Don't put any type of flame heater in your tent/bivi it will use up the oxygen and leave carbon dioxide.

 

[Native Nathan]

Another angle to look at:

I have a Foam Roll mat and an Issued Bivvy Bag
I use mine outside

Bivvy Bag £85
Rollmat £15

The mat protects me not only from the cold ground but small rocks, twigs etc that might tear or puncture my Bivvy bag
I'd much rather shell out £15 for another mat
than have to find £85 for another Bivvy Bag

 

[Deaner666]

I've slept both ways but never really found much of a benefit to keeping the mat inside the bag. I don't seem to slip off when it's outside, but keeping it inside is definitely more of a faff.

I'm all the way with Native Nathan... I can't believe no one else mentioned this point. Your roll-mat - whether it's a cheap closed-cell foam or a posh thermarest - is likely way more robust than your bivy bag.

 

[tiger stacker]

Matt outside, someone mentioned boots as a anti roll wedge, try placing your bergan rucksack on the slide off side. Gas heater inside is tempting fate, why not use a nalgene or sigg bottle as hot water bottle. Although a skull cap and socks left on will help no need to sleep with all your clothes on.

 

[copper_head]

I'm an innie.