Generic “Tyvek” – heavier than silnylon

Tyvek may be heavier but it is far stronger for the weight. The fabric type tyvek used for kites and such may be a bit lighter but im not certain.

Yes, standard construction Tyvek is heavier. Makes for a great groundcloth if you are dealing with sharp jagged rocks, cactus and broken glass, but I would never use it as a shelter.

I tried once:-)

Tyvek homewrap is about 1.85 oz/yd2

At 1.85 oz/yd2, the groundcloth should weigh 4.3 oz or a little less than the factory one. Looks like the off-brand is a lot heavier than the Dupont. I'll have to keep looking for a source.

The comparison of Tyvek House wrap with silnylon is a little confusing. Why would the weight of sil compared with house wrap be helpful? Silnylon is material used for tent canopies, of course, but Tyvek housewrap is not a suitable tent wall fabric. Housewrap is not used by the commercial tent manufacturers for tent canopies. It is porous compared to Tyvek 1443 and is usually associated with use as a ground sheet but not as a canopy or rain fly. So comparing house wrap with silnylon seems as useless comparing the weight of your ice ax with the weight of your down jacket. A useful comparison would be Tyvek 1443 with Silnylon, which has been made here many times by the fabric wonks.

Well, please forgive a newby. My intended use is as a groundsheet; the factory groundsheet for my tent appears to be silnylon and I had assumed from my reading here that I could save some weight by making one out of housewrap.

I think you'll find house wrap is fine for groundsheet use. I've sold a few hundred metres of it for that purpose and have nothing but good feedback from my customers, many of whom have returned for more.
P.M. me if you want a link to my sales page, I don't want to break house rules by advertising it directly here.

Hi Will,
If you want to save weight over the stock groundsheet I would recommend you buy some polycro groundsheet from gossamer gear. It's about 1.5 oz for a 40 inch wide by 96 long piece and is surprisingly durable, excellent for a tent groundsheet.

That's what I use on my Fly Creek UL 1. The Fly creek uses a pretty light fabric, I suspect it might be a little lighter than standard silnylon (1.3 oz/yd2) so it's pretty hard to find something lighter.

Tyvek is excellent too, but of course will be heavier, though more durable.

For free tyvek just go to somewhere near you that building is going on. Look for a building or house that is framed and sheeted and even putting on the tyvek. Just ask for the big scraps. You will get more tyvek than you will even need. The scraps just go into the garbage anyway.