Bushwalk Australia

I have a Tyvek ground sheet (the heavier type) which I purchased ‘off the roll’ then washed 3-4 times to soften it up a bit. It’s been used for about 30 nights over the past 3-4 years.

I camped in rainy conditions this weekend and noticed that water soaked through where weight was on the fabric. This also occurred when I knelt on it. There don’t seem to be any actual holes - though there are some creases where the fabric is softer.

What’s your experience with Tyvek?

I remember reading somewhere that it's HH rating was around 1000-1500, I don't remember exactly and I might be wrong. But that would suggest water could be forced through without too much weight needing to be applied.

I replace my Tyvek groundsheet, for a Macpac Minaret, every 12 months, during which it is used about 8 to 10x in all conditions. The last replacement in June showed a few pinholes and punctures from small stones, and a noticeable attraction for water to be absorbed. It had also become progressively harder to clean up, which probably does nothing to improve "waterproofness", of whatever degree. From my experience, regular replacement based on how often the material is used would be better than leaving it to chance.

I think the use of tyvek is less for waterproofing and more for holeproofing whatever you're putting on top.
You can make things like tarps from it but they work more like a wicking cotton fly rather than 100% rainproof.

There are many types of Tyvek.
here is an old chart :

Tyvek home wrap makes a wonderful ground sheet, but the fact that it is cheap and easily replaceable is a key part of this. Over time you'll definitely prick lots of tiny holes in it, particularly when crawling around on it. You don't notice these until you're suddenly on wet ground. If I'm expecting a dry trip or protected camp caves, I take an old ground sheet with me as it's just about stopping dirt and protecting my mat. If I expect wet weather I take a newer one to deal with water.

The other point is that the process of washing the ground sheet (to stop it making so much noise) definitely seems to shorten the lifespan. It's still fine as a protective layer, but the waterproofness seems to get degraded. As a result I no longer do this. Just use enough rocks on the corners / sides to stop the wind catching it and the crinkliness doesn't matter.

Tyvek is NOT waterproof. If pressure is applied (as in a groundsheet with your weight on it), it will leak. It's ideal for preventing rips, tears and holes forming in your tent and for keeping it clean.
If needing something extremely lightweight, long lasting AND waterproof - use DCF.

I've sat on Tyvek on very wet ground and not had any water come through. But its waterproofness certainly does degrade.

I have a friend who uses HardieWrap. It's marginally heavier than the usual Tyvek Homewrap, but it's much more durable in our experience. Things like coral fern stick to the Tyvek, damage fibres and . This doesn't appear to happen with HardieWrap. I've been keen to get hold of some, but my friend's source is no longer available. Anybody have access to HardieWrap in bushwalker-friendly amounts?