I get what you’re saying about air sealing—makes a ton of sense in most cases. But living in a house built in the 1890s, I’ve learned there’s a point where you can go overboard with the caulk and foam. Old places like mine need to breathe a bit, or you end up with trapped moisture and all kinds of weird issues (think peeling paint, musty smells, or even mold). I tried going hardcore on air sealing a couple years ago, and let’s just say... the house didn’t thank me. Had to undo some of it after the attic started smelling funky.
Insulation’s still important, but sometimes I think folks forget every house is its own animal. For me, it’s about finding that sweet spot—tight enough for comfort, but not so tight the house can’t do its thing. Anyone else run into this balancing act with older homes?
Totally get where you're coming from—old houses are a whole different beast. I’ve seen folks seal up every crack and then end up calling me about condensation on the windows or weird damp spots in the corners. Ever notice how some of those older plaster walls just seem to want to breathe? I always wonder, is there a “right” amount of air exchange for these places, or is it just trial and error until you hit that balance? Sometimes I worry new insulation methods don’t always play nice with 100+ year-old materials... anyone else ever regret using spray foam in an attic with old wood?
Sometimes I worry new insulation methods don’t always play nice with 100+ year-old materials... anyone else ever regret using spray foam in an attic with old wood?
I’ve actually run into that exact issue. Used spray foam in a 1920s attic, and the old rafters started showing signs of moisture not long after. Turns out, those materials really do need to breathe a bit. In hindsight, I’d probably go with mineral wool or something less aggressive—seems like a safer bet for these older structures. Finding that “right” air exchange is tricky, but I lean toward erring on the side of a little more ventilation rather than less.
I’ve seen that too—spray foam can be a double-edged sword in these old houses. I’ve had better luck with cellulose in a couple of my projects. It’s not as airtight, but at least the wood doesn’t get trapped moisture. Sometimes “old school” methods just work better for these places.
Timing really depends on the method and the house’s quirks. For older homes, I like to break it down room by room—start with a walk-through, check for any weird gaps or historic details you want to keep exposed. With cellulose, you can usually get a small room done in a day, but factor in prep and cleanup. I’ve found that working in stages helps avoid surprises, especially if you want to preserve original trim or plaster. Sometimes it’s less about speed and more about respecting the character of the place.