Insulating walk-up attic in 1910 duplex in mixed-humid Climate Zone 4a
I have read *many* of your articles and comments (Martin Halliday, Dana Dorsett and Allison Bailes) about insulation, but still am having a couple of problems preventing me from getting moving on a project.
We just bought a 1910 1268 sq ft stucco balloon framed duplex (side by side), moved in at end of January last year. Despite no wall insulation, very old storm windows and badly installed fiberglass batt at the unfinished basement ceiling, the first floor is pretty comfortable for us. We have upgraded most rooms’ storm windows (and added one where there was none), and got a programmable thermostat (keep it at 67 in evening when home, let it fall to 56 overnight/when out, have it at 63 during morning hours when getting ready to go out). We do not plan to insulate the walls, because we didn’t use any air conditioning/don’t have a bathroom fan/have a sometimes wet basement, so we want to trust the plaster/stucco assembly to move moisture out.
But here’s the problem. There is a walk-up attic (not behind a knee wall, the door is on the full second floor), with floor boards almost all the way to the edge. (One floor board near one edge was pried up; there is about seven inches of space from edge of floor to eave walls or slant of roof). There is NO insulation in the attic. And you can see the sky in a few places in the walls in the attic. And the upstairs is *noticeably* colder than downstairs, you feel the difference 3/4 way up the stairs.
We have a more than 25-year-old natural gas boiler and 24-year-old roof (still sound), so there are a lot of big $$ demands coming soon.
We hired one insulation contractor, and I don’t trust him at all. He wanted to do open cell foam against sheathing in between attic joists (some 2 by 6, some 2 by 4), leave it without any ignition or thermal barrier, was only promising R13 in the smaller joist spots, and wanted to do closed-cell foam against the pine-plank party wall. Claimed there would be no problem with either humidity from the house or spotting leaks in roof after installation. Also said we would have to air seal ourselves where you can see the sky with can foam. Ignored the fact this doesn’t come close to R-38.
Even this would cost about $3,000, which would be a more than 10-year payback at the temps we keep the house now, especially if we didn’t get that much reduction in heating cost b/c it would only be R-20 or R-13. (If we get foster kids, we will be required to keep it much warmer, so our bills would be far higher than what we had last year)
I do have a just-shy-of 9 inch space between the lath of the ceiling below and the top of the floor boards. Because the place is small, we do have quite a few containers/boxes in attic (and a cedar closet there too). We had an electrical upgrade in attic, so I think we’re safe on knob and tube; no can lights on second floor.
Does anyone know how to find a consultant in the Washington DC area that can give us advice of what to do without being biased toward that company’s insulation product?
Is there a way to create an insulated hatch that would cover the top of the entire staircase, if we sought to insulate under the floorboards instead of against the roof sheathing? It is something like 30 feet long by 29 inches wide, if memory serves.
Or do we need to just wait until we redo the roof and do rigid foam under new shingles combined with foam against roof sheathing, and then drywall? If so, what is the proper approach for the party wall?
Can send pictures if you like, or more accurate measurements, but would be happy to pay for a consultant if I knew how to find one. Asked the city environmental dept., and they were no help, and local utility doesn’t sponsor this kind of thing in our jurisdiction.
I want to do the right thing for the planet (see avoiding a/c even in this climate!) and improve our comfort, but also don’t want to spend so much that it will take decades to recover the cost in lower natural gas bills.
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