Which underlay for click engineered boards on chipboard subfloor?

[redhexagonal]

So I have these click engineered boards that are 2200mm x 180mm, and 14mm thick. I’m laying them on a chipboard subfloor on joists on the 1st floor. The chipboard is sound and mostly flat. The company i bought the boards from recommended 3mm rubber crumb underlay with a silver vapour barrier.

I’m unsure about this first because I’ve read you shouldn't use a vapour barrier on a suspended floor, and second because I’ve read rubber crumb contains heavy metals and I don’t want to deal with a load of toxic dust if I ever take this up again.

What is a suitable underlay for this kind of flooring that won’t be too bouncy , ideally that will help deaden noise transmission a bit too?

Thanks

 

[crazydaze]

Duralay Multitex would be perfect.