Would you like a warranty with that?

I'm having work done on my roof today. Over the latter part of the summer, we began having leaks in our portico roof (the part of the roof that goes over the driveway where it comes up by the front door - circular drive). We had several places in the portico roof where the ceiling had fallen through because of the leaks. We're glad to get this started before we get any more rain, but at the same time it's hard to part with the amount of money that this is going to cost. We have a flat-roofed house, which I would not reccommend to anyone. I don't know who came up with this design, but these kinds of roofs are susceptible to leaks and you constantly have to be doing something on a regular basis to keep your roof from leaking. We are having a kind of plastic covering put on the roof that will guarantee it will not leak for something like 20-30 years. Too bad we can't fix our bodies that good. My one-year-old new knees are only supposed to last me another 7-14 more years. I know a lady who has had 2 knee replacements. She says that is all you can have. You can't have them replaced more than twice. This lady is at least 20 years older than me, but it's still scary to think about. I talked to this one guy who had his knee replaced and there was something wrong with the mechanism and he had to go back into surgery so they could repair it. Talk about bionic! I asked him if they replaced it with a new artificial knee but he said, no that they just repaired it. I wonder if it came with a warranty?