Honestly, I gotta push back a bit on the incense stick trick—works in some spots, but it can miss stuff if the draft is coming from under the floor or through the crawlspace. I’ve seen folks get obsessed with windows and baseboards, but half the time it’s those old rim joists or even plumbing penetrations in the basement that are leaking like crazy. Did a job last winter where the crawlspace was basically acting like a wind tunnel, just like you said... but until we sealed up the sill plate and some weird old vents, nothing else made much difference.
half the time it’s those old rim joists or even plumbing penetrations in the basement that are leaking like crazy
That rings true for me. In my 1890s place, I spent weeks chasing drafts with caulk and weatherstripping upstairs, but the real breakthrough came after I tackled the basement rim joists and sealed up some ancient pipe holes. The incense trick barely picked up anything down there, but the difference in comfort was night and day once those gaps were closed. Sometimes the “invisible” leaks are the worst offenders.
Definitely agree—those rim joists are sneaky. I’ve had contractors focus on attic insulation, but honestly, the ROI from sealing up basement penetrations is way better in drafty old houses. It’s not glamorous work, but it pays off fast.
Rim joists are one of those spots folks just don’t think about until they feel that cold draft sneaking in around their ankles. I get why everyone’s obsessed with attic insulation—heat rises, right? But in these old houses, air leaks down low can be just as brutal for comfort and bills. I’ve seen people dump thousands into blown-in attic insulation and still complain about cold floors and high heating costs. Nine times out of ten, it’s those basement rim joists and utility penetrations letting all the warm air escape.
Honestly, sealing up those gaps with rigid foam or spray foam isn’t glamorous work—nobody’s posting before-and-after shots of a sealed rim joist on Instagram. But if you’re looking at ROI, it’s hard to beat. I’ve had clients notice a difference within days, especially in the dead of winter. The job itself doesn’t take forever either. For an average-sized house, you’re looking at maybe a day or two if you’re thorough and not rushing. Compare that to the mess and disruption of redoing all your attic insulation.
One thing I’d push back on a bit: sometimes folks go overboard with sealing every tiny gap in the basement and forget about ventilation. You want to stop drafts, but you don’t want to create moisture problems or trap radon. It’s a balancing act—tighten up the envelope, but make sure you’re not causing other headaches down the line.
If you’re weighing where to start, I’d say hit those rim joists and big penetrations first. It’s not flashy, but your toes will thank you... and so will your wallet when the next utility bill comes around.
Totally agree—rim joists are the unsung heroes of comfort. It’s wild how much difference a few hours with a caulk gun and some foam can make. Love that you mentioned ventilation too. People forget you can go too tight and end up with a whole new set of problems... balance is key.
