canesisters
Garden Master
I have used those feed bags that are a woven plastic mesh as weed barrier (under mulch) in areas that I plan to set up and leave for a few years.  Like when I set up Mom's old wooden swing in that WEEDY corner of the yard.  chopped, pulled and mowed weeds. covered in a heavily overlapped layer of feed bags & mulch.  I've pulled a few surface weeds - things that fell & germinated in the mulch or things that crawled in from the sides, but so far NOTHING has come up from underneath. 
As long as water will get through, I don't see why your plan won't work. Give it a try!
			
			As long as water will get through, I don't see why your plan won't work. Give it a try!