How much fabric needed for a bivy?

Generally 2.5 yards can do it depending on your design. 3 if you want to play it safe.

Thanks Nathan!

Good estimate

Maybe you should actually design it first. Get dimensions of the pieces you need. Width of the fabric you're buying. "Lay it out". Then you will not buy too much extra or not have enough, not have to compromose the size of your bivies to fit the fabric you have.

Maybe do one bivy first, the one with the cheapest fabric.

What kind of fabric are you using? Is silnylon 1.3 enough for the floor? Is pertex quantum durable enough for top? If not, which fabrics for top and bottom?

Jerry,

I am thinking about mocking one up with tyvek first, think that would work?

Tom, I plan on using thruhiker Shield sil on the bottom of each bivy

tyvek mockup? good idea

tyvek is stiff and hard to sew. You could use an old bed sheet. Don't do any details, just the bag to see if it's big enough for your sleeping bag and so forth.

thru-hiker shield has worked for my bivy bottom. Kind of slippery so I put some silicone:spirits to not slip around so much.

Evolution of a MYOG bivy

Figuring out size will be the most difficult part of making the bivy in my experience. Actual sewing of the bivy was quite easy.

Derek