In regards to them being weakened by UV exposure.....I've not noticed much 'degredation' of any kind....true there may be some but....I wouldn't hesitate to use these for shelter building or pack repair. I keep them in the car too for use as a band clamp on hoses. The only thing I'd have concerns over using them for would be suspending my (or any persons) weight. When I cut them down it took quite alot of force to do so.