[enochian]

I thought it was as simple as having a couple layers of polyiso foamboard glued to my 0.5" birch plywood.

But then I read that foamboard cannot be exposed. So I have to glue a piece of drywall on top?

 

[Bud9051]

The insulation in the attic usually needs perimeter protection to prevent it from falling through the hatch or getting damaged as you go up and down. Then, the perimeter plywood can get an air tight cover and everything below remains as it was.

The other part I mentioned is air sealing that hatch, which would be hard with rigid foam below.

Bud

 

[joecaption]

It's not a living space so I would not worry about it being exposed in an attic.
If you still have to cover it, do it with drywall not plywood.
The reason it needs to be covered is because it gives off toxic fumes when burned.
If a fire is that bad it gets to that attic door that would be the last of my worry's.