The original builders of my house used a material called "Aluma Sheath", also known as Dennyboard, to sheathe my house. Dennyboard is a radiant coating on two sides of a 1/8 sheet of a fiberous material similar to what pegboards are made out of. It disintegrates when it gets wet and is very susceptible (and seemingly quite delicious) to insects, which eat out the core and leave nothing except the sheet of metal or mylar that's not thick enough to be used as tinfoil. It obviously was never providing any lateral rigidity, so in theory none should be required now although it is called for in code.
In the past thirty-two years, the Dennyboard has rotted as it was exposed to the elements. There was no tarpaper, housewrap, or other material between the Dennyboard and the brick. So I'm left with brick, which while a decent and fireproof rainscreen, is decidedly not waterproof, and there exists (many,many) ways for insects and moisture to directly access the insulation and sheetrock layers of the building envelope.
Is there a good and code-compliant way -- and barring that, just a good way -- to rectify this situation WITHOUT REMOVING THE BRICK OR INTERNAL STRUCTURE? My current concept is not code compliant as far as I'm aware. (It might be, but I don't have the experience to know.) I am planning to remove all of the sheetrock and insulation in the affected rooms, cut the brick ties (most of which are rusted anyway) after supporting the fascia from the exterior, slip housewrap between the studs and the fascia, and then slip a sheet of 4x8 1/2" (or less, I think I saw 1/4") of extruded foam sheathing between the studs and the housewrap. The entire thing will be re-anchored and affixed from the outside using CTP Grip Ties or a similar product. This should provide a watertight, sheathed, and even (insufficiently) thermally broken envelope without having to do any tearout work beyond the sheetrock.
Can anyone comment on the legality or feasibility of this idea? Tearing down the brick fascia is not possible; I'm very hesitant to alter the structure of the house in any way without getting a lot of (expensive) engineering advice first. Note: I have not begun tearout of the drywall yet and won't until this winter; the assumption that the brick ties are mostly rotted is because the fascia moves pretty freely and after doing a bunch of work to the roof and trim above this area I got a good look down inside between the fascia and the internal wall and saw the rotted dennyboard.