Tyvek for underquilt cover?

[pdxhanger]

I picked up some Tyvek cheap at my local fabric store. Now I'm trying to figure out how best to use it.

I am considering sandwiching it between 2 layers of thin fabric (ripstop? taffeta? 1.1 something-or-other?) and sewing attachment loops to use it under my underquilt for colder temperatures. This would give me a flexible modular system, only using (and carrying) the tyvek in cold temps.

I have no experience with Tyvek. Would sandwiching it between 2 layers of nylon fabric substantially increase it's durability/longevity? Also, I'm wondering how much tyvek really breathes. I have some fabric that is waterproof but may not be breathable (my fabric store does cheap stuff that is not well identified), and I'm wondering if it would be better to use something else. If so, how important would it be for it to be waterproof? And how much windproofing does the tyvek provide? One option for the sandwich fabric would be light taffeta which wouldn't provide any extra wind- or waterproofing.

Any and all experience, opinions, suggested are appreciated!

[OutandBack]

I believe most prefer breathable UQP'er. Keeps you dryer thru the night.

[nuttysquirrel]

tyvek is breathable. i don't see the point of sandwitching it between layers? its tough enough for groundsheets and can be sewn.

[SimonMc]

I would use Tyvek Type 14, which you can source from Quest Outfitters.

Tyvek breathability demonstration

[pdxhanger]

I believe most prefer breathable UQP'er. Keeps you dryer thru the night.

What is UQP? I'm afraid I don't understand.

[nuttysquirrel]

under quilt protector

[OutandBack]

tyvek is breathable. i don't see the point of sandwitching it between layers? its tough enough for groundsheets and can be sewn.

OP it would be a simple test to see if it was breathable enough.
Before cutting just do a gathered end UQP with some shockcord and sleep in it one night.
The old backyard test...

[nuttysquirrel]

or just try to suck air thru it.

[Poedog]

I use a peice of kite-grade Tyvek (soft, light) as an UQP, my groundsheet, and sometimes I'll gather the ends and make a hammock for my smaller forest brethren.

As an UQP I use it only to protect the quilt from blowing rain and ground splatter. I attach it to the underquilt with 4 binder clips, and let it drape under the quilt without touching it, allowing air to flow between it and the quilt. Works like a charm, and it's multipurpose.

[ntxkayakr]

+1 for how poedog uses Tyvek UQ protector etc as with almost all breathable "waterproof" or at least water resistant fabrics there are often condensation issues at certain humidity levels and temperatures. (i.e. dew points)