Day 12
They got to it and made pretty good progress; they didn't really need a ground crew at this point. |
Art shot: another little vignette that happened to be right out the back window next to my desk. |
So let's think about this for a moment. The screws they had were sized to
go through strapping and the foam layers, and if sent into just the foam
face would penetrate deeper than usual. What if they had hit the wiring
instead of the steel
box? Two inches higher and they might have. The screw is potentially in
contact with some part of the foam's
foil facing, at any of the layers thereof. This leads to two and a half
potential scenarios: 1> the screw contacts a hot lead, thus electrifying
it and anything it's touching to the AC hot voltage, or 2> the screw
lands on the ground or neutral, or perhaps the grounded box itself, and
thus grounds the foam too. The "half-th" and less likely scenario is that
the screw manages to cut through enough insulation to *bridge* across hot
and something else, causing an
immediate and obvious short which hopefully kicks the circuit protection
instead of starting a fire in the wall. But it's the first two situations
that could be much more subtle and hazardous because the error wouldn't
be immediately obvious.
If part of the foil-face was driven hot and a guy put one hand on it and the other on something grounded like a scaffold pole or a corded power tool, he'd get 120VAC right across the chest -- probably with good solid conduction, as they were sweating pretty hard most of these days. If connected to ground it could remain un-noticed entirely, but a screw driven into a piece of wire at all could either slowly become a short or an arc-fault later or possibly *another* screw somewhere else on the wall that hit a hot would complete a wacky circuit between there and a grounded point through any combination of foam sections. A stretch, perhaps, but not impossible. Extraordinarily bad ju-ju all round. I had done what I could to try and indicate where such potential [ha, get it?] electrical pathways were through the walls, but I couldn't cover all possibilities. With base construction of this vintage there's no guarantee that wiring was correctly fastened to the midlines of studs everywhere rather than just slung haphazardly through the bays, and I was really trying to account for that. A few peeks in through the stripped-down sheathing above my marks with a flashlight might have been able to located any problem points, not to mention revealing the stud offset issue itself. In fact I should have tried that just for curiosity's sake at the time, but it was hard to get near the walls being demoed without feeling like I'd be in the guys' way or raising questions they didn't want to think about. |
Day 13
Major task for today, though -- the massive rear overhang. They started collecting measurements for the plywood. |
These parts were quite a bit heavier, and infeasible to hold up against the wall while aligning. A couple of screws served as quick support pegs. |
Some of the plywood went on, and the second ladder half was raised and wrestled into place. |
The plywood run was completed, precisely matched up to the rest of the over-deck above. |
The plywood itself was a little bendy, though, so they added little midway braces underneath at about every other crosspiece. |
Here's what it all looked like shot through the new soffit space: a colonnade of rough framing suspended over empty air. |
The whole electrical issue was still gnawing at my brain, and I wanted to
try and determine if there were any other issues between the insulation
job and the wiring. As I pointed out, some of the scenarios could be
subtle and ordinarily impossible to detect in the building process.
I figured an energized foam panel would have been noticed long since,
unfortunately the hard way, but what about a grounded one? Were they
perhaps already
grounded through some path I couldn't see? Foil-face against flashing
metal in turn against moist cinderblock could do that, but at what
resistance level?
Much could depend on just how the various parts were in contact, but
I wanted to get some idea of baseline.
A voltmeter between a foam panel near the side door and an electrical ground from inside showed a decidedly nonzero level of AC, but nothing I could actually feel. Problem there was that a voltmeter is too sensitive and likely picking up the capacitive effects from nearby wiring. I needed a test setup that could actually put meaningful current through any possible fault and indicate where there might be a dangerous path. When I started going after the foam with a multimeter I'm sure that any of the guys who were still undecided about me being a nutcase or not made their decision right then and there. The lead guy seemed fairly interested in this, though, and encouraged me to continue investigating. Maybe he was just leading me on, but it didn't matter -- I was on a major roll of geekdom, and I was going to figure this out. It seemed more likely that an errant screw would contact a ground than a hot, with two out of three wires in the romex and the surrounding iron connected to the neutral/ground side of things. The effort would therefore focus primarily on finding ground faults. |
Ground-fault testing the foil-face didn't actually take that long, and
meanwhile my roofing-material samples from
ATAS
had arrived that day so I wanted to check out how they might match up
against the siding. Jumping back a little here -- in my roofing research
I had a nice conversation with the tech people at ATAS and they fedexed me
a handful of swatches for the types/colors I was considering. What I was
looking for was aluminum and a fairly good solar reflective index (SRI) in
the coating to keep the whole roof cooler, which implied the lighter end
of the spectrum. Their whole chart is on the website in a PDF with
surprisingly accurate representations of the appearance, given how photos
can so often be off with respect to lightness and color balance.
The PM had brought me a sheet of siding samples from GP a week or so before, and I already had a similar folder from CertainTeed on hand. I held both sets of those up next to my view of all the *other* houses around me to make sure nothing I'd consider was the same as them. The swatch of GP's generic "blue" immediately spoke to me, and it didn't take long to make my pick so they could order the stock. This was one of those indeterminate colors that's almost no color, changing how we see it depending on how it's lit, what else is visible nearby, etc. Cool but not saturate or punchy. I happen to like colors like that; for example the car is another one of those that a lot of people call "grey" but I see as a more subtle green. So the roofing color wanted to be in keeping with that theme but still have the physical attributes I needed. The siding hadn't really been unpacked yet but a couple of trim pieces had been pulled out to check, so I could match up my little fistful of roof colors to it and do some serious art-fagging. These two shots were in diffuse fading daylight with the same white-balance; see how the blue vinyl and even the roof samples wind up looking different just a few minutes apart? I had already mostly eliminated a couple of these in my mind but wanted to give the whole set a fair shake. The middle color, "Champagne", had a definite greenish tinge almost like the car but I knew that if I did anything in the domain of *green* that my neighbors who had to put up with twenty-plus years of the previous putrescence would come kill me. The mottled galvanized-steel that got sent along just for comparison was just plain ugly. The clear-coat aluminum looked like tinfoil and I didn't really like it -- unfortunate, because it had far and away the best SRI. That left "Dove Grey" and "Silversmith", the latter of which some part of my brain was already favoring. This particular evening my neighbor was having some sort of family gathering, with daughters and spouses and relatives all hanging out in their driveway next to my side yard. For completeness and good relations I figured I'd consult him to make sure I wouldn't make any choices that would irritate him for the next twenty years. I walked over with all this stuff and stood there with the big silver box behind me and asked, "whatcha think?" He was funny, saying "you need a *woman* to help make decisions like this!" which really was a little sexist but it so happened that he had several women available right there. A bunch of folks clustered over and one of his daughters, I think, pointed straight at Silversmith and said, "ooh, that one's kind of jumping out at me." They also sort of liked the Champagne, but more importantly they were just loving the general class of picks I was making including the siding color. They thought it and just about any of the roofing would work together beautifully, and I think my ol' green-disapproving neighbor himself was really digging this conversation. It all helped, lending third-party perspective to my own thoughts. |
Day 14
This didn't work out, though, because the gap was too tight to push the edge into. A bit of cussing and metal-mangling later, he gave up for the time being. |
Finally it was fastened in. These guys are really good at the rock-climbing-style steep roof carpentry techniques. |
Lots more soffit had to get installed, pretty much everywhere. |
This involved some more gymnastics on the cheek-walls to work up into the split as far as possible. |
The first piece happened to fit *perfectly* on one side. |
The other side needed just a little shave-down to fit. Every so often we find it necessary to use a saw as a power sander to do that teeny little bit of trimming we need... |
_H* 121203