I get where you’re coming from. After a couple decades of projects, I’ve learned to accept a little imperfection, especially in older homes where nothing’s truly square. I’ll tweak until it’s functional and looks decent, but if it takes hours just to shave off a millimeter, I call it good enough. There’s always another project waiting anyway.
I’ve learned to accept a little imperfection, especially in older homes where nothing’s truly square.
I hear you there—older houses are a whole different animal. Sometimes I’ll measure a window opening three times and still end up with a slight gap on one side. I’ve found that shimming and backer rod can only do so much before you just have to let it be. Out of curiosity, do you ever find the aluminum frames themselves are out of square from the factory, or is it mostly the rough openings giving you grief?
Sometimes I’ll measure a window opening three times and still end up with a slight gap on one side.
That’s the story of my life with these old walls. I’ve had a couple aluminum frames come slightly racked right out of the box, but honestly, it’s the rough openings that usually throw everything off. My trick is to dry-fit first, check for daylight around the edges, then shim where it matters most for air sealing. It’s not perfect, but it beats fighting the whole thing into place and ending up with drafts.
I get the whole dry-fit and shim routine, but I’ve actually found that sometimes it just masks a bigger problem, especially in these old houses where nothing is square. I used to do the same—shim here, caulk there, hope for the best. But after a couple winters with cold spots and a window that never quite looked right, I started getting a bit more stubborn about prepping the opening itself.
One time, I had this 1920s bungalow with plaster that looked like it’d survived a few earthquakes. I kept blaming the window frames for not lining up, but after pulling out the old trim, I realized the sill was bowed and the sides were out by almost half an inch. No amount of shimming was going to make that frame sit flush. Ended up biting the bullet and rebuilding part of the rough opening. Not fun, but after that, the frame dropped in like it was made for it.
I’m not saying everyone needs to rip out their sills or anything, but sometimes shimming is just putting lipstick on a pig. If the opening’s way off, you’re always going to chase gaps and drafts. Aluminum frames especially don’t have much forgiveness—they’ll show every little twist or bow.
On the other hand, I’ve had a couple new-construction jobs where the openings were dead square and still managed to get a frame that was racked from the factory. That’s its own headache... but at least then you know it’s not your walls.
Guess my point is, shimming works up to a point, but if you’re always fighting gaps on one side, it might be worth checking if the opening itself is the real culprit. Sometimes you gotta go a little deeper than just fitting to what’s there.
I get where you’re coming from, but I think there’s still a place for shimming, especially if you’re not ready to tear into the structure. You mentioned,
For me, in a 1950s ranch with slightly wonky openings, careful shimming plus backer rod and low-expansion foam actually got things tight enough—no drafts this winter. Maybe not perfect, but I didn’t have to demo half my wall. Guess it depends on how far out of square things are and how much hassle you want to take on.“sometimes shimming is just putting lipstick on a pig.”
Totally get what you mean about shimming not being just a bandaid. I’ve had to do the same—my place is a ’60s split-level, and nothing is truly square. What’s worked for me: stack shims in opposing directions, check with a level after every tweak, and don’t over-tighten the screws or you’ll end up tweaking the frame out of alignment. Backer rod and foam are lifesavers for drafts, honestly. Sometimes “good enough” is way better than tearing the whole wall apart... especially when it’s below freezing outside.
Sometimes “good enough” is way better than tearing the whole wall apart... especially when it’s below freezing outside.
Couldn’t agree more—sometimes you just have to call it a win if the window opens and closes without a fight. My house is old enough that I think the floors are doing their own thing, so getting anything square is basically magic. I’ve snapped more shims than I care to admit trying to “get it perfect.” At this point, if the drafts are gone and nothing rattles in the wind, I’m happy.
Funny you mention snapping shims—I’ve gone through a whole bag in one weekend trying to “fix” an 80-year-old frame that just refuses to cooperate. Sometimes I wonder if these old houses are just stubborn on purpose. Honestly, as long as the wind isn’t howling through the gaps, I’m calling it a success. Perfection’s overrated when your toes are frozen.
I hear you on the shims—last winter I was retrofitting a set of aluminum windows into a 1920s bungalow, and it felt like every stud had its own agenda. Ended up with a pile of snapped shims and a few choice words for whoever built that place. Sometimes you just have to accept “good enough” when the whole house is out of square. As long as the lock latches and you’re not getting a breeze, that’s a win in my book. Funny how old houses seem to fight back every step of the way...
Man, I totally get what you mean about the studs doing their own thing. My “new” place is from the 1950s, and I swear none of the windows are even close to square. Tried installing an aluminum frame in the kitchen and ended up questioning if my level was broken or if gravity just works differently in old houses.
I kept thinking maybe I was missing some pro trick or special tool, but nope... turns out it’s just a lot of trial, error, and muttered cursing. After about the third snapped shim I started using those composite ones instead of wood—seemed to help a bit since they don’t split as easily, but getting everything lined up still felt like herding cats.
Is there some secret to making these frames fit better in old houses, or is it just always a game of compromise? I keep telling myself as long as it opens and shuts without a draft, that’s good enough... but part of me wants those crisp lines you see in renovation shows. Maybe that’s just TV magic?