Last winter I knitted a few throw rugs from "yarn" I cut from old t-shirts. It took 10-12 adult tees to make one decent sized doormat. Size 13 or 15 needles.
The yarn would be good for weaving too, I think. The rugs take forever and a day to dry, they are pretty heavy.
Here's a video on how to cut tees into continuous strands. The useful bit starts around 1:15.
I just cut up about a dozen t shirts and made them into yarn. My husband made me some awesome knitting needles from large dowels and I have been having a ball! I was thinking it would be fun to knit a patchwork type of hammock with the yarn, using the netting patterns used for the grocery bags, k2tog, yo...what do you think? Will the yarn hold up?
“The best things in life are nearest: Breath in your nostrils, light in your eyes, flowers at your feet, duties at your hand, the path of right just before you. Then do not grasp at the stars, but do life’s plain, common work as it comes, certain that daily duties and daily bread are the sweetest things in life.” Robert Louis Stevenson
Location: Torrey, UT; 6,840'/2085m; 7.5" precip; 125 frost-free days
I don't think I'd invest a lot of time in that without testing it first! But maybe double stranded with something strong but not so soft would work. The rugs are tightly knit, so I don't worry about the old shirts falling apart. A looser knit and a couple hundred pounds would make me nervous. Do post some pictures of what you end up doing!