Tyvek for ground cloth

Tyvek: Yes, this will work. Plenty of people do this. I use the stuff made for kites, called 1443R. It is lighter than the housewrap and less stiff. But the housewrap will work, too. With either one, run it through the washer once or twice to soften it up. Air dry it.

Regarding ski poles as trekking poles: are the adjustable? Aren't downhill ski poles significantly longer than trekking poles? How long are the poles and what is your height?

The skipoles are a few inches to long. I will take the grips off and cut them down. Should my forearms be level with the ground while gripping the poles?

That's how I adjust mine; arms parallel or just slight below when on level ground. Ultimately, it is whatever feels comfortable to you, of course. Can you take them out on a few day hikes before your longer trip?

Of course also consider the height you want the poles when pitching your tarp before you cut them. I use adjustable poles, and I'm on the short side, so I set them longer for pitching a tarp. If you're taller, then you may do fine with a single length for hiking and shelter.

Ya I'm short so I might leave them. Doing a training hike Saturday so will test them then.

Yeah, the kite-making Tyvek is about half the weight of the house-wrap stuff. Not as durable, of course.

This awesome site carries 14M, a type related to 1443R, which they claim is slightly better:

http://questoutfitters.com/uncoated_fabrics.htm#TYVEK

What I really prefer though is polycryo, almost half again as light (as the 14-series Tyvek), and just as durable I think:

http://gossamergear.com/polycryo-tent-ground-sheets-protection.html

Someone at GG told me that the material in the single large piece is slightly heavier than that in the 2-pack of medium pieces.

Rumor has it that this is the same stuff as shrink-film used for cheap window weather-proofing and available at hardware stores, but I haven't checked for sure.

You could also spend a little more and get some .5 or .7 cuben. I bought some cuben from dutchwaregear for $12.50 per half yard. Its so light. Probably last longer than tyvek. It will also not absorb water like tyvek or get dirty.

Actually, I'd argue a bit on cuben. Here are figures I came up with, when trying to figure out my last groundcloth:

weight (oz per sq-yard)
polycryo (large) 0.68
polycryo (medium) 0.54
Tyvek 1443R 1.18
Tyvek 14M 1.25
Tyvek building-wrap (approx) 2.3

Only the lightest grade of cuben is lighter than the polycryo, and the heaviest cuben is heavier than the 14-series Tyvek. The cuben may do better on durability, or on ability to keep something sharp on the ground from puncturing your pad, I'm just not familiar enough with it to judge.

I am going to use the tyvek for this trip because it's free but I really like that coated silpoly. Might buy some later.
Scott