It should be said here that the 4" wood machimbre (tongue & groove) boards and heavy beams that were used as a base for pouring the roof slabs, and which form the very attractive open-beam cathedral ceilings in the upstairs bedrooms are, for the most part, now, non-structural. This is in the sense that we could remove them and the reinforced slab roof would still be in place. The only small area which would have to be worked over bit by bit (should all the wood be removed) would be the perimeter joint where the walls meet the roof slab. Here work would have to be done replacing (with concrete grout and metal ties) the ¾" thickness of wood that is sandwiched between the top of the wall and the underside of the slab.
In the skirt-roof I chose, only the very lowest exposed board had moisture-caused rot in it, and the protruding beam ends were in good shape. The first task was to insert a hacksaw blade between tabla and viga to cut off the nails holding the board in place.It was then a simple matter to insert a good board in it's place, toenailing up thru the corner of the beam to affix it. Very fortunately, there was enough good machimbre material left from the demolition of the skirt-roofs from the laundry building and over the double doorway into the dining room space, that I didn't have to locate a sawmill which could work up new matching t&g boards. All the wood that replaced the bad in the roofs was treated on all sides with festermicide, a preservative and termite & fungus preventative, before being put into place.
The flashing technique which I used involved inserting the slightly opened up angle between the tarpaper layer and the wood, lapping any ends in the angle stock by several inches, and caulking the metal in place along the upper angle fold and the concrete slab. I located a good quality, gray slate-colored acrylic latex/silicone calafateo (caulk), which worked as an adhesive as well as a sealant. Since the joint shouldn't "work" any, other than some expansion of the metal in the hottest weather, and no freeze-thaw cycles to worry about, this should be a long lasting joint. If there are any problems, some additional caulk squeezed into any cracks that develop should take care of things. Due to the pounding out of the angle, the metal hangs down outside the edge of the tablas, providing a sharp drip edge for water to fall free of the wood. I worked around all the roof edges reachable by stepladder (the porch and living room window skirt-roofs), leaving the upper story for the younger, nimbler guys to complete.
The only other issue to be worked out was how to replace the rotten beam ends that were under the various roof overhangs. One beam over a living room window obviously had problems, and when I started working on it is was clear it had to be totally replaced, due to end rot and then termite damage farther up. This meant, for this beam end, actually cutting it off almost flush using my sierra reciprocante (reciprocating saw), then digging out the remainder well into the wall surface with various large brocas (drill bits) and cincels (chisels) and wrestling the remaining wood out of the hole. The guys used a a good beam end salvaged from the laundry room roof for a visually perfect replacement, which they cemented into the hole in the wall and nailed into the t&g boards which were cantilvered above it.
Next: Foundation & Sewer Lines