Couldn’t agree more about shims being a temporary fix. I’ve seen too many jobs where folks just wedge them in and call it done, only for the window to go out of square a year later. For drafts, I’ve had better luck with rope caulk—sticks through winter, peels off clean in spring. As for those weatherseal tapes, mixed bag here too... some brands hold up, but the cheaper ones seem to peel right off once the temps drop.
I tried shimming a window in my place last fall, thinking it’d buy me time till I could do a full fix. It held for a bit, but by spring, the frame was out again—guess the shifting just kept going. Rope caulk worked way better for drafts than those foam tapes, at least for me. The tape started peeling once the first cold snap hit... maybe I just picked the wrong brand. At this point, I’m leaning toward just biting the bullet and rehanging the whole window.
Totally get what you mean about shims being a short-term fix. I’ve done the same thing on a couple of my old windows—seems like the house just wants to keep moving no matter what I do. Rope caulk’s been my go-to for drafts too, especially in weird spots where nothing else sticks. Rehanging sounds like a pain, but honestly, sometimes it’s the only way to actually fix the problem for good. Weird how some of those foam tapes just give up as soon as winter hits... maybe it’s the brand, or maybe they just don’t like old wood frames.
Foam tape can be so hit or miss, especially with older wood frames that have a bit of character (aka warping). I’ve had better luck with the thicker, closed-cell stuff, but even then, cold snaps seem to make it shrink or peel. If you’re thinking about rehanging, I’d suggest checking if the sashes are square first—it’s surprising how much difference a slightly out-of-square frame can make. Have you ever tried using wood epoxy to fill out the worst gaps before caulking? Sometimes that holds up better than shims alone, at least in my experience.
I get where you’re coming from with epoxy, but I’ve actually had mixed results with it on old frames. Sometimes the wood just keeps shifting and the epoxy cracks after a couple seasons—especially in spots where there’s a lot of movement. I’ve found that a combo of shims and flexible caulk works better for me, since it can move a bit with the wood. The trickiest part is definitely those weird angles where nothing seems to sit flush... I guess every old house has its own quirks.
The trickiest part is definitely those weird angles where nothing seems to sit flush... I guess every old house has its own quirks.
This is pretty much the story of my 1927 bungalow. I hear you on epoxy—tried it twice, and both times it looked solid at first, but as soon as we hit a humid summer, the frame shifted and the epoxy just popped right out. I think the issue is that the older woods really do keep moving, especially if there’s even a little moisture getting in.
The shims + caulk combo has been my go-to for the past few years. I usually start by gently prying the frame open just enough to slide in cedar shims (they seem to resist rot better). I tap them in until things feel snug, then cut them flush with a sharp chisel or utility knife. After that, I use a high-quality, paintable silicone caulk—never the cheap stuff, it cracks way too fast. The flexibility helps a ton with those seasonal shifts.
For those odd angles, I’ve found it helps to trim the shims at a matching angle before sliding them in. It’s a bit of trial and error—sometimes I end up shaving them down two or three times before they fit right. If there’s still a gap, I’ll backfill with a little caulk or even a sliver of wood glue and sawdust, but only in spots that don’t move much.
One thing I learned the hard way: don’t overstuff the frame with shims thinking it’ll be “extra solid.” The wood needs a little room to breathe, or you’ll just end up with new cracks somewhere else. And yeah, every old house is like a puzzle—what works on one window doesn’t always work on the next.
If you haven’t already, it’s worth checking for any underlying rot before shimming. I had a window that kept sagging no matter what I did, and it turned out there was a hidden patch of soft wood behind the trim. Digging that out and patching it before shimming made all the difference.
Anyone else ever try those adjustable plastic shims? I’ve only used wood, but I’m curious if the plastic ones hold up over time, especially with all the movement in these old frames.
That’s a solid approach. I’ve had similar luck with cedar shims and silicone caulk—definitely agree on skipping the bargain brands, they just don’t hold up. I’ve wondered about the plastic shims too, but something about them makes me think they’d be too rigid for old, shifting frames. Maybe I’m just set in my ways, but wood always seems to flex just enough without snapping.
I’ve wondered about the plastic shims too, but something about them makes me think they’d be too rigid for old, shifting frames.
I get where you’re coming from—wood’s got that classic feel, and it does flex a bit. But honestly, I’ve had surprisingly good results with the heavy-duty plastic shims in my 1940s place. They don’t rot or compress over time like wood can, especially in damp spots. Yeah, they’re stiffer, but sometimes that’s what you want for a snug fit and less air leakage. Maybe it depends on how much movement your frames actually see, but I wouldn’t write off plastics just yet.
Plastic shims have really come a long way, honestly. I used to be a wood-only person too—just seemed like the “right” thing for an old house. But after a couple of soggy seasons where my wood shims started to get a bit spongy, I tried the plastic ones out of desperation. They’re definitely firmer, but I actually appreciate that when I’m trying to square up a frame that’s settled over the years. The fit feels more secure, and I haven’t noticed any shifting since.
That said, if your frames are moving a lot—like actual seasonal expansion and contraction—you might still get some creaking or minor gaps. The plastics don’t compress the way wood does, so you lose a bit of that forgiving nature. For me, though, the tradeoff has been worth it in terms of durability and not having to redo work every couple of years. Plus, no worries about rot if there’s a bit of moisture sneaking in.
Guess it’s one of those “depends on your situation” deals. If you’re dealing with a lot of movement, maybe stick with wood or mix both? Otherwise, I’d say plastic’s definitely worth a try.
The plastics don’t compress the way wood does, so you lose a bit of that forgiving nature.
Yeah, that’s the part that bugs me sometimes. I tried plastic shims on a door frame last fall—super solid at first, but when the house shifted a bit over winter, I ended up with a hairline gap. Never had that issue with wood, but then again, I’m tired of replacing soggy shims every couple years. Maybe mixing them is the way to go, like you said. Old houses always keep you guessing...