UKH

Looking to get a sleeping mat (Alpkit cloud base) to use inside a lightweight bivvy bag (been looking at the Alpkit Hunka).

My question is when used on rocky ground, potentially on a bivvy ledge up a route, would you be in danger of popping/damaging one of the air filled sleeping mat's?

Does anyone have experience with this?

Cheers 

Rich

Be careful putting larger inflatable mats inside a bivvy bag, they can take up a lot of room and stop your sleeping bag from lofting.

I would call the Hunka more of a sleeping bag cover  than a bivi bag, especially for use on other than grass.
If you get one go for the XL if your of larger proportions.

I am old school on this and use a closed cell foam roll mat at all times. I've had too many 'let downs' with self inflaters in the past. 

Go XL. I wish I had and I'm on the smaller side 

I'd say both are quite fragile for stoney ground. This is easily solved by the use of a good closed cell mat either as a replacement for the cloud base or as well as, under it. 

Very interesting cheers. I will have a look around at slightly tougher bivvy bags, as I'm not sure I will always be on the softest terrain.

A friend of mine mentioned army surplus bivvy bags as well which might be on the slightly tougher side

I think I will look into a closed cell foam mat. I was trying to save space in the pack, as I know the air mats pack down very small, but I feel durability outweighs size.

Thanks all for your help

You can get Tyvek house wrap, on that auction site. Get a 2m strip, to use as a groundsheet. It very strong and light. Its what they make festival wristbands out of, I've been told.

I've got the Hunka xl and the Elan. If its going to rain or be midgey, then the Elan is better. The Elan can be used without the poles, to get a best of both worlds approach, but its slightly heavier and bulkier.

Might be worth considering that a foam Mat can go on the outside of your pack in the compression straps. The z type are good for this.

I thought this was going to be a lonely hearts thread.

edit: albeit quite a specific one!

I'd do the same or even use a combination of a 3/4 length closed cell foam mat with the air mat on top, and leg section protected by the rucksack. 

Always worked ok for me and the 3/4 length mat is so light that it's no problem to carry strapped to the sack.

Do you find the Elan is noticeably bulkier than the hunka XL when packing? 

The Elan does look like a much nicer setup.

I use an army surplus bivvy and have done for years. Apart from being weighty and cumbersome, I love it. Very robust and the green has some advantages!

Yes yes yes, this this this. You could even seam-seal it to the bottom to stop it blowing away and make setting up easier if you're going to be on a ledge or something. 

For 'proper' bivi use — ie where you could be sleeping anywhere, on any manner of inadequate ledge — I think the classic closed-cell foam mat is the winner. They're indestructible, infallible, and will happily go places where any sort of inflatable mat would be awkward, cumbersome or plain annoying. I've experimented extensively now (albeit not in very demanding places, no sloping ledges thus far!), and I'm very certain you can't beat the old-school on this.

For taking up routes, cut it down. It doesn't need to be full-length when you have packs, ropes, etc as well.

For bivi comfort, like wild camping where you can predict having a human-sized bit of accommodating ground, I have an Exped Synmat and rate it highly. Or I did rate it highly, until I used it on a stony alpine bivi. It's never stayed fully inflated since!

After many years of alpine bivvies ( I'm a slow learner! ) I would agree with what most others have said in this thread.

- Keep mat under the bivvy bag, not in it.

- If on soft ground or smooth rock an inflatable mat is a lovely comfort.

- Where there are stones, gravel, sharp glacial granite powder and on sloping ground a foam mat cut to size, such as a Zlite, is a safer option. Often carried outside the pack.

- If bivvying high ( perhaps on a glacier ) or where weight is less of an issue ( not far from a 'lift' ) sometimes a  foam mat can be put under an inflatable mat for extra warmth and comfort.

- Use your rucksack, rope and spare clothes for extra insulation and comfort. ( 'Comfort' may be an optimistic word ).

The Elan, when packed, is about the size of a 2L plastic bottle. If you take the poles out, it will scrunch down a little more. The Hunka xl, about 1L. There is a little room for further compression with the Hunka. E.g. You could squash it down between other bits, rather than stick it into a compression sack.

+1

If its really bad weather , make sure your mat does not collect water, no bivi bag will cope between a backside and a puddle. Slightly sloping or cut some drain  holes in the foam mat.

I suspect an inflatable mat isn't going to work well on rough terrain as there's too much scope for air to move to the bits not in contact with the ground i.e. the pressure points won't have much air between you and the ground and you're going to feel the ground through the mat and it's going to be more susceptible to punctures.  The last thing you're going to want in a bivvy situation where you're losing heat relatively quickly is a lack of insulation due to a puncture.