Two Melbournes, two different attics
The inland subdivisions off Babcock and Wickham went up between the 1970s and the 1990s, and most of those attics are still carrying their original depth of material. They were built to the code of the day, which was well short of the R-30 a Florida ceiling is held to now, and thirty years of settling has taken more off the top.
The waterfront strip is a different assessment. Those homes span a much wider build window, and the salt air adds a decade of wear to anything mechanical sitting outside. What we look at there is less about depth and more about what the humidity has been doing to the insulation and the attic deck.
