Vapor Barrier My deck ceiling

[Gemini]

I want to insulate our enclosed deck and heat it. I went into the attic and discovered there is no vapor barrier above the deck portion of my home. Instead of ripping out the plywood sheeting that is currently the ceiling can I put vapor barrier on the warm side of the plywood then drywall over top of it. Making it Drywall / vapor barrier / Plywood sheeting / attic insulation

[pushkins]

It would be easier and better to just insulate the attic space above the porch with "faced" insulation.......Problem solved !!
Don't forget your going to need to use faced insulation in the floor joists below the floor as well.