Hello, everyone. I recently watched the Ask TOH segment where Tommy helped a homeowner supplement the insulation in his attic. As you may recall, the homeowner already had insulation in the floor joist cavities- Tommy showed him the value of adding more insulation perpendicular to the joists.

I would like to accomplish a similar task in my attic. The difference, however, is that I have some plywood flooring nailed down over the joists. I don't need this flooring since I don't use this area of the attic and it would be very difficult to remove.

I know that I have insulation beneath the plywood, so my question is: can I simply add the new insulation above the plywood or do I need to remove the plywood floor?