I dealt with this on my 92 Winnebago. I tried taking down the material and stripping off the foam and gluing it back up, but that didn't work. The material is too heavy and once it begins curling and falling down, it doesn't like to go back to a factory-flat form, regardless of how much glue I used. I ended up just stripping the ceiling and using ceiling paint. It came out very nice....although the picture in the above pose looks pretty cool.
And regardless of the quality of material, that foam deteriorates with time and heat. It happens on cars and everything else. It's not always a defect or water intrusion that causes it to start falling down...just time. Good luck if you decide to go with it.
Tom