House retrofit 08

House energy retrofit project 08

Day 0

[Click any image for a larger version.]

It was nice to finally have a hard start date, as I really wanted this thing to get going. The builders were wrapping up the prior project and were ready to move some of their gear between sites. They arrived one afternoon to drop off a trailer with a bunch of scaffolding, ladders, and miscellaneous other large tools of the trade. And several buckets of fasteners and hardware. They put some of it in the basement, which by that time had a generous cleared area for them, and would actually start work the next day.
After a quick refresher tour around the place the project manager seemed really pleased with all the prep work I had done to accomodate them, joking "We'll be done with this in a week!" He said that his guys had been looking forward to this project as sharp contrast to one down in Jamaica Plain they were on before, a more urban area where they had a serious space-squeeze and were having to foot ladders in neighbors' yards and such.

This was the right time to do a little publicity, and send mail to various local lists and friends telling them how an "unusual renovation" was just beginning here and that they should wander by and look at it. While a deep energy retrofit isn't necessarily for everyone, I was hoping it would at least give other people some ideas.

Day 1: the main retrofit begins

It was a perfect day to tear a house apart -- mostly sunny, with moderate temps and fairly low humidity. The crew began arriving in stages, probably hindered slightly by figuring out their first time driving to the property [read: poking at their GPS units], and the first guys on site found me up on the roof taking off my redneck-patch tarp and battens. I used the tarp to wrap around the Daikin unit to protect it somewhat from flying debris.
First thing they did was unload the trailer and their pickup beds, and brought everything into the backyard.

They wasted absolutely no time starting to rip and tear, as a couple of guys grabbed the stripping shovels and began attacking the siding even before everybody else had arrived.

This moment represented a significant point of no turning back for me; it felt like once the old siding had been breached like this, the retrofit had to proceed to completion for the house to ever become a home again.

Those first small stripped areas were to better facilitate attaching scaffolding brackets to, so they could get their Alum-a-pole system set up. Having the siding out of the way would reveal more solid material to screw into.

Taller poles went up onto the high shed-dormer wall.

The rest of the crew had filtered in by now -- there were eight or nine guys on the job for this first demolition phase. The project manager gathered everyone up for a brief orientation walk around the house, pointing out some of the features and pending changes and things like where I'd marked the walls where electric wiring was likely to run up inside.

I must admit that like they said they were going to, they do come to a jobsite fully self-sufficient -- coffee, food, port-a-john [which was actually delivered a day later, minor mis-coordination] , plenty of drinking water, and even bringing in their own microwave to facilitate hot lunches. In theory, as little drain on a client's resources as possible; all they needed was power which they mostly pulled from the convenience GFCI in the HVAC disconnect box.


The first efforts focused primarily on the front and the roof, including removal of the little portico piece. Here I would vindicate my design thinking for eliminating it. Once it was stripped and opened up to the framing, it seemed a lot simpler a structure than I'd thought -- not giving me any second thoughts about it, just observing that it didn't seem that complex to disassemble.

But parts of it were tough and well nailed together, and resisted the demolition efforts a little here and there.

Here was another symbolic moment, not to mention one of several fun action shots -- a little part of the house's old facade, or a component of its supposed curb-appeal [hah] or "cute little Cape" personality or whatever -- required only a bit more force to finally make it go spinning to the ground, and the whole nature of the front would be different from then on.

Another few minutes and a bit of sawzall work later, the rest of its support structure fell and was promptly cut up for disposal.

From here it was obvious that the portico wasn't really an integral part of the house structure, it was just sort of tacked onto the front. Well, if the term "tacked" could apply to the pair of frankly *massive* slabs of wood forming its upper frame, which seemed like total overkill for the amount of roof they had to hold up. But the main roof sheathing ran continuously right behind its roof, explaining why I couldn't find any obvious opening into the portico volume from inside the kneewall area upstairs.

The ugly amorphous brown thing hanging out isn't a monster hornet nest, it's just more of that crappy crepe-paper Kimsul insulation that was in the rafter bay. We can't see any of my crap stored in the kneewall area behind there, but if I had gone inside and opened the hatch into that space I would have seen daylight.

With the old rake-boards removed at the gable, I could now see how the original siding and roof sheathing went together at the transition. I hadn't thought about it that much, but here it's clear that all the siding up along the roofline had to be site-cut to match the angle and placement.

With the obviously decrepit wood around the periphery of the roof gone, the rest of the wood underneath was looking surprisingly sound.

Next time I happened to look at the HVAC stuff, I found that the guys had constructed a quick-n-dirty plywood rooflet over it to protect the whole thing from falling debris. They probably rightly figured my tarp wouldn't be good enough for what they were about to drop overboard, and took appropriate proactive measures.

And drop they did. They spent a couple of hours shoveling shingles off the edge onto the tarps below, and pulling up large chunks of stuck-together assembly where it could easily be pried loose ...

... and summarily flung off into the yard below. Whee! Hulk smash!

As soon as the front was clear enough with the lowest courses of sheathing taken off, the "chainsaw retrofit" could begin. Only here it was done with a sawzall. This would conveniently take away even more decayed wood in the discarded rafter ends.

After getting sawed most of the way through, a quick knock with a hammer and the rafter tails fell one by one. This wouldn't compromise the house structure at all, because most of the stress on any rafter end is straight down and maybe slightly outward where the "birds mouth" sits on the top plate.

The same thing happened all the way along the front, thus simplifying the whole roof-to-wall transition. What's hard to see in any of these shots is the fact that the rafters were actually cut about 3/4 inch back from the outer face, to allow space for replacement sheathing wood to sit and form the new simplified corner.

A friend came over to view the chaos later in the day, and I happened to be standing in the backyard examining a couple of the rafter cutoffs as she walked up. As I enthusiastically burbled "Look what I *don't* have any more! Rafter tails!" trying to express the awesomeness of why they'd been lopped off the house in the interest of a different shape, she probably thought I was nuts.

Meanwhile, the guys working on the shed-dormer roof in the back had it almost clear.

With the shingling and tarpaper gone, daylight could stream in through the spaces between the tongue-and-groove sheathing planks. [The gaps in plank sheathing are intentional, to allow for expansion.] This had to be the weirdest way I had ever seen the attic.

Like at the front, the lowest sheathing and soffit pieces were gone and now I could see straight out the rafter bays to the backyard -- over the catch pans I had put in and shuffled around in a mostly futile attempt to try and catch some of the leaks and stave off the inevitable.

That's why I was somewhat amazed that the shed sheathing didn't have far more water damage than we found. In fact, only this smallish area would need total replacement -- the very part over where the yellow mold had been starting to creep up the structure underneath.

As the guys ripped up that part of the sheathing, they tried to huck the boards straight into the dumpster from there -- succeeding most of the time. While it made another nice action shot, this one happened to miss and clattered onto the ground.

I went over to pick it up and realized it was one of the moldiest boards from that area, featured near the beginning of section 01, and now I could examine that fungus up close.

I didn't spend too long on this, though, because now that they had that whole area of the attic open I wanted to hop up and get rid of the rest of the obvious mold on the rafters themselves. The guys were fine with me coming up and straddling across the scaffolding and house framing to wipe away the yuck, after which I sprayed the area liberally with anti-mold stuff and said "all yours!" as I ducked back out of the way. While not every homeowner gets up on the working ladders and staging, they could quickly see that I'm fine working at height and knowing what I can step on.

The open part got re-sheathed in new plywood later, which I didn't get a picture of but it was clear that the rest of the deck up here was in pretty good shape. There's the hole where the chimney used to stick through, with all the old tar and flashing gone and about to get framed in and leave the stink-pipe as the only remaining roof penetration.

The toilet-stack hole had to get enlarged a little later, so they could get a cutter in and chop off the cast-iron pipe and transition it to PVC before exiting the roof. First noted in part 01, this was my idea but based on numerous references I'd found about condensation resistance -- a metal pipe sticking through the roof would transmit cold to the inside and collect moisture that would then drip down the chase, so changing to PVC as low down as practical would remove that thermal bridge. What I didn't get was a look at, let alone a shot of, the tool they used to cut the pipe but it was probably similar to the chain cutter described here.

Why "stink pipe"? The phrase seems to have been coined when the first "water closets" were being built, as plumbing designers began to realize [sometimes the hard way] that sewer systems need to be vented. This page gets into some detail on the subject.

The project-manager had gone out to fetch the rubber coupler earlier, and at this point was on the roof helping work on the pipe-cutting operation but had left the coupler on the bench down below. He spotted me near it and called down for me to toss the coupler up to him, which I managed to in a beautiful lob up two stories' worth and right to him. He snatched it out of the air and said "you're *hired*!"

That made reference to my amused observations about the way the builders toss stuff to each other and fling stuff down. I quickly learned that this team has highly developed ability to throw and catch, as that's how numerous items travel between the work area and the ground. They're very good at it -- even with heavy stuff like tools and screwgun batteries, hunks of wood, water bottles, demolition debris, or whatever, and often one-handed -- it was often like a well-practiced circus act and I was having a total blast watching the guys go at it. I began referring to it as "air traffic control". It obviously saves a lot of time and climbing, so this sort of elegant juggling is an integral part of their workflow.

The front roof deck was soon entirely clear, and we all stood looking at its surprising [well, to me] structural soundness and going "this is like-new perfect!" This was a huge relief, as I thought there would be a whole lot more rot repair going on.

More work was needed before the new edge could be filled in, though, including yanking the rest of the portico-area trim and cutting back its supports the rest of the way. I don't think the big beams were cantilevered very far into the house framing, but it was evidently infeasible and/or not worth removing them entirely. The point was to just get it all flat.

With the top of the shed-dormer stripped it seemed appropriate to start ripping the "cheek-wall" sides of it along with.

I refer to these thin roof strips and the walls next to them as either cheek walls or wing walls, because I heard them interchangeably called both.

Art shot: a bit of tarpaper or shingle hung up in the tree, amusingly intercepted on its trajectory to the dumpster from above.

In the thick of the activity, the lumberyard delivery truck arrived with all the foam insulation and some other supplies.


The delivery guy couldn't drive his forklift all the way into the driveway with the dumpster and other stuff in the way, but even these big bundles of the polyisocyanurate foam are so light that two guys could just carry them toward the back and stack them up. [The wheelbarrow is not involved, that's just another batch of debris headed for the back door of the dumpster.]

Seven bundles of foam, and a bunch of plywood and strapping. This was now the supply stock area. This also shows the work-table they'd set up out back, for battery chargers and the lunch-nuker and whatever else.

Now that they had plenty of plywood, they could start ripping down some of the 3/4" stuff.

And here's what they did with it: filled in for the removed sheathing, and formed the new and very simplified roof-to-wall transition. Right here is the essence of the "chainsaw retrofit", as a simple membrane wrap over this gives a solid air-seal.

Here we see why the rafter tails couldn't just be cut back flush with the old sheathing, as the outer surfaces all have to match. A few gaps and holes didn't matter, as all this would no longer be an air-sealing element and it was all going to get covered with new layers -- it just had to be flat. As the new wood got attached, the locations of the rafter and stud center lines were marked and transferred outward.

Then it was time to start applying the first layer of waterproofing, using peel-n-stick Grace Ice & Water Shield. They used the "ripcord" feature to only remove one half of release paper to stick onto the sheathing, letting the lower half with its backing still on flop over the edge where it would later cover other material.


A few nails to temporarily tack the layer down would prevent the edges from flapping in the breeze. Here's where the house started becoming a giant advertisement for various building products, and the guys all referred to this stuff simply as "Grace" for obvious reasons.

They rolled out another course all the way across, and then kept working more of it upward.

The day's demolition had already filled the dumpster and more needed to go into it, so the PM had called for a pickup. The driver dropped the empty one next to the full one, and then hooked up to the full one and tried to haul it onto the roll-off truck.

With all the shingles and wood this sucker was *heavy*, and had wound up placed on slightly low and soft ground on one side. As the roller on that corner dug in, the thing almost twisted off his hook and tried to tip over but was fortunately caught by the tree next to it -- which sustained a minor injury but at least handily prevented a big nasty mess all over the neighbor's lawn. As the driver repositioned to regain control of the thing and slowly dragged it out, it left a giant rut gouged into the ground with torn-up pine roots hanging out of it.

We made sure the new dumpster sat a little farther onto the property, on harder and more level ground. Chalk up one learning experience.

What I'll probably never know is what happened to all this debris. At least it wasn't a huge lead-paint hazard, per my tests, but while Synergy and I had talked about a *possibility* of recycling the shingles and such which would have required a second dumpster and more careful sorting that didn't even come close to happening, and everything got indiscriminately pitched into one skip and hauled away and that's all we knew about it.

A line of cleats was attached to the little roof strip, and from there the cheekwall cleanup could get finished. At this point the new wood had also been cut and slotted in on the shed dormer, closing up the rafter bays the same way as in the front.

I realized later that the guy on the staging [as they call it, rather than scaffolding] was at that very moment taking a bunch of measurements for where all the rafters sat relative to this edge, and writing them down on a scrap of plywood.

That led to these amusing items kicking around the worksite for the rest of the job. I still have them, in fact.

The back deck needed the same Grace treatment, but they needed to pause at the [new, brilliant white!] stink-pipe and make sure it was flashed up correctly with some smaller pieces.

More courses went up the deck the same way, as the release paper was simply fed overboard for the ground guys to pick up.

Gracing the cheekwall strips was a little trickier, as the cleats had to be removed and transferred to on top of it. Note how the Grace extends up the sidewall a little, soon to have other water-resistive material flashed down over it.

Those unfamiliar with the ice & water shield products might think "but they just drove a bunch of screws right through it!" with a bit of alarm. The flexible bituminous layers of this are designed to seal around small penetrations, so for the most part this is perfectly okay to do. *For the most part.* There are some caveats, explored later.

With the whole front of the house now flat, a layer of Tyvek could go onto it and get attached up under the Grace flap. This wasn't typical flat housewrap, they'd brought "drain wrap" which has many vertical creases to create tiny channels up and down for water and/or air circulation. So while this would be the ultimate ohshit water barrier for anything that managed to get through the layers yet to be added, it would still allow the sheathing to breathe and dry, ultimately toward the inside after the rest of the assembly was in place. But it wouldn't trap thin layers of moisture against the wood.

Here's another trick I learned that day: you can bulk-cut a long roll of tyvek down to the size you need by just ripping through it with a skilsaw.

We were nearing the end of their first workday at this point. The guy in the background was beginning the daily ceremony of raking the yard around the house. They did this and a magnetic nail sweep every afternoon before departing, to try and leave the homeowner with relatively clean surroundings overnight.

With July weather fairly unpredictable, some quick battens were added to fasten down edges that could flap up in a thunderstorm and let water in. One of the prime directives governing the work methodology was to keep the building watertight when they weren't there, and for the most part they were really good about that.

The basement turned into a massive tool dump, as they put everything away for the night. I wouldn't have this part of the basement back for another two months, but they were definitely appreciative of having all that stash space that could be secured. They were all cleaned up and on the road for home around 4pm -- their leaving time would vary quite a bit day to day, as they worked on a completion-of-tasks basis rather than trying to meet set hours.

Here's how the chimney hole got framed in -- simple and effective, and now covered with Grace on the outside. As I'd said, like the chimney was never there.

The vent-stack adaptation was a nice clean transition and left a healthy length of PVC before reaching the roof deck. One might think here that since the pipe is open to the outside, why wouldn't cold air come down and make the lower section of cast-iron cold anyway ... but sewer and septic systems tend to be warmer than their surroundings, and in general warmer air tends to waft upward out of them. It's thermal *conduction* we wanted to prevent here.

I was also really glad I'd strung up a tarp under the chimney hole, because the stripping operation had let a large amount of detritus fall in and all I had to do was fold up the tarp around it and take it outside. There was actually shingle grit *everywhere* in the attic that had fallen in through the sheathing gaps as they shoveled the deck. Much later in the project I vacuumed a lot of that up off the ceiling drywall below.

They had run a little short on Grace that day and weren't able to complete the roof membrane, so they tarped over the ridge for the night and hoped for no rain -- they generally don't like using tarps, as they are often kind of ratty and tend to leak, but it's what they had. With the lapped Grace layers over the rest, this attic in theory would never see water again.

And here's how things looked after day one. The guys had accomplished quite a bit, and *I* was tired from just chasing them around with the camera all day. And we would do it all over again tomorrow.

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