What surprised me (and what went wrong) installing my own windows

Yeah, stacking too many shims always feels like a temporary fix. I tried that on my old place and after the third one, I just didn’t trust it anymore. The window never quite sat right, and I’m pretty sure it leaked more air than before. Trimming the framing is a pain (especially if you’re dealing with old plaster or weird angles), but it’s way less nerve-wracking in the long run.

I’ve found that getting the rough opening as close to square as possible makes everything else go smoother - less fiddling, better seal, fewer drafts. It’s wild how much difference a tight, well-insulated fit makes for keeping the house comfortable and cutting down on energy bills. I get why people try to avoid the mess, but honestly, that extra effort up front pays off every winter.

Guess it’s one of those “do it right or do it twice” situations...

I get where you’re coming from, but I’ve actually had some luck with shims - at least when you’re careful and don’t go overboard. In my old farmhouse, the framing was so out of whack that trimming just wasn’t practical without tearing up half the wall. I used a couple solid cedar shims, sealed around them, and honestly, it’s held up for years. Not saying it’s perfect, but sometimes “good enough” really is… good enough, especially if you’re working with weird old construction and don’t want to open a can of worms.

That’s actually a good workaround, especially with old houses where nothing is square. I totally get the “good enough” approach - sometimes you just have to pick your battles or you’ll end up gutting the whole place. That said, I’ve found shims can be a bit of a double-edged sword if energy efficiency is a priority. Even small gaps around them can become air leaks over time if they aren’t sealed up tight.

What’s worked for me: after setting the shims, I always run a bead of low-expansion spray foam around the perimeter to close up any sneaky gaps. Then I trim off the excess and finish with flexible caulk on the interior side, just to be sure nothing’s getting through. It’s not pretty behind the trim, but it keeps drafts out and makes a real difference in winter.

Definitely not saying you need to go full perfectionist mode, but if you’re noticing cold spots or higher bills, it might be worth checking those shimmed areas again. Sometimes it’s just a matter of adding a little extra sealant and calling it good.

That’s a solid approach, and I’ve had similar results with the spray foam and caulk combo. It’s wild how much of a difference those tiny gaps can make - my old place would get these weird cold drafts right by the trim until I sealed everything up. I do wonder sometimes if all the extra sealing is overkill, but honestly, my heating bill dropped a bit after I did it, so maybe not. Sometimes “good enough” really is good enough, especially when you’re dealing with 100-year-old walls that have their own ideas about being straight.

Can’t argue with the heating bill going down, but I’ve actually found that sometimes you can go a little too far with the sealing - especially in these older houses. I did the foam and caulk thing all around my new windows last winter, and while it definitely stopped the drafts, it also made the place feel almost too airtight. Ended up with condensation on the insides of some windows I’d never seen before, and a bit of that musty smell after a few weeks. Old houses just seem to want to breathe a bit, you know?

Here’s what worked for me after a bit of trial and error:

1. Sealed up the obvious gaps, especially where you could literally see daylight or feel a breeze.
2. Left a few spots (like above the trim or at the bottom corners) just a little less tight, so air could still circulate.
3. Got one of those simple humidity sensors to keep an eye on things - turns out, my place was creeping up over 60% humidity once I’d sealed everything tight.

I get wanting to stop every draft - nobody wants to pay extra for heating - but if your place is older and has that “character,” sometimes it does better with a touch less perfection. I guess it’s about finding that balance between comfort and letting the house do its thing. Plus, chasing every last gap can turn into a rabbit hole... ask me how I know.

Anyone else find that too much sealing made things weird?

Totally get what you mean - after I did a full round of caulking and weatherstripping in my 1920s place, the air just felt... stale. My bathroom mirror started fogging up even with the fan on, which never happened before. I ended up cracking a window open just a touch most days, especially when cooking or showering. The drop in drafts was great, but like you said, there’s definitely such a thing as too tight. Old homes really do seem to need that bit of airflow or things get funky fast.

Interesting you mention the stale air - after I swapped out my old windows for tight new ones, my place started smelling musty, especially in the closets. Did you ever try adding any kind of vent or trickle vent to balance things out, or just stick with cracking a window?

Did you ever try adding any kind of vent or trickle vent to balance things out, or just stick with cracking a window?

Honestly, I tried the whole “just crack a window” routine, but in the middle of winter, that’s just asking for frozen toes. Ended up installing one of those little trickle vents above my bathroom window - wasn’t as tricky as I thought, and it actually made a difference. My closets still get a bit funky sometimes though. I guess there’s only so much you can do without going full-on HRV system, which feels like overkill for a 900 sq ft place. Anyone else notice that newer windows are almost *too* good at keeping air out? My old drafty ones at least kept the socks from smelling like a gym bag…

Yeah, those new windows are like living in Tupperware. I swapped out my old single panes for the fancy double-glazed ones, and now my bathroom mirror never fogs up - but my laundry room smells like a wet dog half the time. Did you notice any weird drafts popping up in places you didn’t expect after the install? I swear I’ve got a mystery breeze coming from somewhere behind my fridge now...

- Had a similar thing after my window upgrade - house got way tighter, but then weird airflow popped up in spots I never noticed before.
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“I swear I’ve got a mystery breeze coming from somewhere behind my fridge now...”