1920’s Baltimore masonry row home, stripped to the shell, floor decks and roof installed.  “Cockloft” roof  framing.  Low sloped roof has modified bitumen over only 2 inches of polyiso and 3/4 ply sheathing.  Roof had been replaced recently, so we’re stuck with that assembly.  

In an ideal world, I use that term with hesitation, we’d have more polyiso and the sheathing seams would have been taped prior to insulation install and tied into the parge coat (and/or our liquid applied membrane – design stages at the moment).

Wall assembly is intello plus over 2×6 framing, held off the masonry (parged), cavities filled with dense pack cellulose (we can argue the merits/pitfalls of this assembly elsewhere), service cavity over the intello, at the moment, cavity will not be insulated.  

I’m happy to provide more details, but given our original plan was an unvented roof assembly, with dense pack gutex (we have enough room at the lowest portion between the roof deck and ceiling framing to get r-49, but holding it below the sheathing about 3 inches) and those sheathing seams aren’t taped (to form our secondary air barrier), should we be modifying the aspects of the roof/ceiling assembly that we have control over?  

ACH50 goal is 1.0.  Spray foam is not an option though I’d be happy to hear how that could potentially be implemented for future projects.  I’m very much aware that there are many ways to do this, and that depending on your constitution, which party line you’re toeing, some are certainly more preferable than others.  

I imagine I haven’t provided nearly enough detail, so please let me know what other information would be helpful.  Thanks very much.