I get where you’re coming from about sealing up every crack, but I’d actually push back a bit on the idea that it’s not worth doing unless you fix all the big envelope issues. Even if your siding or house wrap isn’t perfect, tightening up those window openings can make a noticeable difference—especially in older homes where the drafts seem to find every little path. I did my 1950s ranch last year and just focusing on the windows and doors cut down on cold spots and outside noise way more than I expected.
One thing I learned: foam isn’t always the winner for every gap. Backer rod plus high-quality caulk works wonders in spots where foam just doesn’t want to cooperate, like those weird, uneven gaps around old brick. It’s slower, but it gives you more control and doesn’t expand into places it shouldn’t (like those weep holes you mentioned... been there too).
I wouldn’t say it’s a miracle fix, but every bit helps with comfort and bills. Sometimes you gotta chip away at these projects one spot at a time, even if the rest of the house isn’t airtight yet.
That’s exactly how it went for me, too—every time I thought I’d sealed up the last draft, another one would sneak out from somewhere weird. I got a little too enthusiastic with the spray foam at first and ended up with a window that wouldn’t open for weeks (oops). Backer rod and caulk definitely saved my sanity around the old stone foundation. It’s slow work but honestly, even just tackling the windows made a bigger difference than I expected. Sometimes you just gotta celebrate the small wins, right?
I learned the hard way that less is more with spray foam—once it hardens, there’s no going back if you overdo it. For me, shimming the window square before sealing made a world of difference, especially in an old frame. Patience pays off, even if it feels like you’re moving at a snail’s pace.
Patience pays off, even if it feels like you’re moving at a snail’s pace.
Man, you nailed it with that. I got way too hyped to finish and ended up rushing the caulking part... which I totally regretted when I saw daylight peeking through a week later. Had to redo the whole thing. Also, I underestimated just how wonky my old house is—none of the frames were even close to square. Shims are a lifesaver, but I wish I’d checked for rot around the sill before starting. Ended up having to patch some soft spots after the fact, which was a pain.
And yeah, spray foam is wild. The first time I used it, I thought “more is better,” and then it puffed out everywhere and hardened like some mutant marshmallow. Had to chisel it off the trim. Now I use the low-expansion stuff and go super light.
I guess the big lesson for me was not to rush and to check everything twice before sealing stuff up. Windows are way less forgiving than I thought.
Had to redo the whole thing. Also, I underestimated just how wonky my old house is—none of the frames were even close to square.
That’s the part that got me too. My house is like 80 years old and apparently nothing is level anywhere. I thought shims were just for minor tweaks, but ended up using a whole pack just on one window. And yeah, I learned the hard way that “good enough” with caulk is never actually good enough.
That’s a common surprise with older homes—framing standards have definitely changed over the decades. I’ve found that even after shimming everything as square as possible, there’s always some compromise between how the window sits and how it looks with the trim. Caulking can hide a lot, but if the gaps are too big, it just ends up looking messy or cracking later. Out of curiosity, did you end up pulling off any old casing to get things to fit better? Sometimes I regret not just reframing sections, but that’s a whole other project...
- Pulled all the old casing off—no way around it in my 1940s place. Nothing was square.
- Tried to just shim and caulk, but yeah, big gaps = ugly finish and air leaks. Not worth it.
- Honestly, wish I’d budgeted for some reframing. Would’ve saved time fighting the trim later.
- If energy loss is a concern, those hidden gaps behind the trim can make a difference. Learned that the hard way.
You’re spot on—those old houses are a whole different beast. I ran into the same issue with out-of-square openings in my 1950s place. I thought shimming and caulking would be enough, but once winter hit, I could feel the drafts sneaking in. If I could do it over, I’d bite the bullet and reframe too. The upfront hassle is nothing compared to chasing down leaks later. It’s wild how much energy you lose through those tiny gaps... not to mention the ugly trim lines. Sometimes shortcuts just don’t pay off.
I thought shimming and caulking would be enough, but once winter hit, I could feel the drafts sneaking in. If I could do it over, I’d bite the bullet and reframe too.
I’m right there with you on underestimating how bad those gaps can get. When I replaced the windows in my 1948 house last fall, I figured a solid bead of caulk and some shims would do the trick—seemed logical at the time. But as soon as the first cold snap hit, it was clear that air was still finding its way in. I guess I didn’t really appreciate how much movement and settling these old places go through over the decades. Even a window that “looks” square can be off just enough to make a mess of things.
I’ve been wondering if anyone’s tried using those expanding foam products instead of just shims and caulk? I was hesitant because I’ve heard horror stories about the foam warping the window frames if you’re not careful. On the other hand, just relying on caulk seems a little optimistic, especially with temperature swings.
Another thing that caught me off guard was how much harder it was to get the trim to look halfway decent. You mentioned “ugly trim lines”—yeah, that’s exactly what I ended up with around two of my windows. No matter how much I fiddled with it, there were always weird gaps or uneven reveals. At some point I just gave up and called it “character,” but honestly, it bugs me every time I walk past.
I’m curious if anyone’s found a reliable way to deal with the out-of-square problem without going all-in on reframing? Or is that just wishful thinking? Maybe there’s some clever trick I missed...
- Totally get what you mean about old houses shifting over time. Even when a window looks square, it’s rarely perfect after decades of settling.
-
That made me laugh because, yeah, I’ve got a few “character” spots too.“At some point I just gave up and called it ‘character,’ but honestly, it bugs me every time I walk past.”
- Low-expansion foam can help with drafts if you use it carefully—just a little at a time and let it cure. It’s not foolproof, but better than just caulk in my experience.
- For weird gaps on trim, I’ve had luck scribing the trim to fit the wall (tedious but worth it). Sometimes a little wood filler and patience goes a long way.
- Reframing is ideal but not always realistic, especially in older homes where nothing is standard. Sometimes you just have to pick your battles.