But you know i would rather see you just sort of map out the area in the center of the attic that you re going to use for storage and fill up the rest with insulation because that s the way you re going to get the most energy efficiency.
Plywood in attic over insulation.
Make sure you don t block the air flow from the soffits.
How to lay attic flooring on top of fiberglass insulation.
Before you lay your plywood onto the joists check to see if your insulation is couple of inches above the height of the joists.
Wear long sleeves and pants since fiberglass insulation irritates.
Leaving part at r 19 is fine the rest will still be beneficial.
What you could do is you could put insulation down in the floor joist first then plywood over it and then you could add another layer of unfaced on top of that.
Most attics are dry plywood is a smart vapor retarder with variable permeance.
Your plywood will be fine especially if you are paying attention to airtightness when you build your ceiling.
Put on work gloves safety glasses and a dust mask before entering the attic.
If you lay plywood and it squishes and compacts your.
In most houses getting a 4 by 8 sheet of plywood into the attic is nearly impossible without cutting a bigger hole in the ceiling.
That s clearly your plan if any moisture makes its way to the plywood the damp plywood will dry out on hot sunny days.
If you can do it there really are no down sides except the.
It s not a vapor barrier.
Technically you should pull the plywood but adding insulation above will actually keep the wood warmer and reduce the risk of condensation.