The designers at my firm have enjoyed using Tectum roof deck systems:

http://tectum.com/roofdeck.htm

We are trying to avoid using XPS because of blowing agent issues, so we were encouraged to find out that Tectum offers an EPS option. Ideally though, they would offer a polyiso option. Since they don’t, do any of you know of a similar product out there that offers polyiso instead of EPS or XPS?

Thanks!