is it any good for a groundsheet for placing my sleeping mat on?

looking for something robust and waterproof to lay my sleeping mat on rather than putting it inside my bivi.

Aye, it is Tony.

Nowt wrong with putting yer mat inside tho, least you won't roll off it?

Edit:

I git one of these for Christmas..

http://www.backpackinglight.co.uk/shelt ... WB101.html

'Tis what it's for Tony but be aware that Tyvek isn't 100% waterproof ... direct focused pressure such as a knee, can push water through it. Permavent on the other hand, is completely waterproof and in my opinon probably makes a nicer groundsheet ... ya pays yer money, etc, etc.

Nowt wrong with putting yer mat inside tho, least you won't roll off it?

Nick, me, my bag and mat wont fit inside my bivi...........

cheers Stu.

Used the permavent on the Cafe Racer. Made the inside of a muddy bivvy a whole lot nicer place to be.

Slightly OT, but do people use Tyvek to protect inflateable mat, I've got a Exped Hyperlight and I'm worried about puncturing it on splinters/flint/sharp stones/nails/twigs etc? I've not stayed in a bothy but pictures I've seen show rough wooden benches !

Rich3rd wrote:Slightly OT, but do people use Tyvek to protect inflateable mat, I've got a Exped Hyperlight and I'm worried about puncturing it on splinters/flint/sharp stones/nails/twigs etc? I've not stayed in a bothy but pictures I've seen show rough wooden benches !

I've not had a puncture (yet). The timber used in bothies is planed in the same way that the floorboards in your house are. There's nearly always a brush or two in bothies for cleaning up so you can sweep down the sleeping area if you feel it might require it.

It's one reason I use a bivy bag and have sleeping mat and bag inside as that provides a little puncture protection. It's always best to check the area you are going to lie on though and remove what you can before you put things down.

I’ve got half a roll of permavent left over from a shed build, never realised it was so useful.

i had a tyvek sheet for a ground sht but dont use it, the damn thing is so slippy and scrunchy ( if thats such a word )

pop it in the washing machine, no liquid, very cool wash, softens it up...also softens with use

as Stu says, not actually waterproof, but not bad, tough and cheap

As Shawn says, Tyvek can be 'softened' with a trip through the washing machine. Permavent on the other hand is more 'material like' so doesn't have the same 'scrunchy' properties.

As said above, it will soften over time the more you use it. I made a diy tyvek footprint for my tent as i couldn't source the footprint made for my tent.

I have some of Stu's Permavent as a groundsheet in Deschutes, it work's really well no issues. With a bit of sticky tape and scissors you can make it into a bathtub style groundsheet. I also have an Ookworks bathtub but which is great on a flat surface, slight slope and off you go down it.... seam grip! The permavent is just so easy

If this thread was a cunningly disguised ploy to drive up sales of Tyvek and Permavent, then it's working! Mine arrived today, with an unexpected bonus in the parcel... Cheers Stu!