I live in a top-floor apartment with a flat roof.
19 years ago (when built) they put in R2.5 PINK Batts in the flat roof. They are not working so I want to upgrade.
Should I have the R2.5 removed and put R5 PINK Batts or should I just add Sisalation on top of the R2.5?
What will insulate my apartment the best?