Funny, I had the same debate with myself (and my wallet). I’ll admit, the Marvins do feel more solid—my office window’s got that same “tank” vibe. But honestly, if the install’s sloppy, even the fanciest window won’t save you from drafts or leaks. Still, I get what you mean about peace of mind. Sometimes you just want to open a window without feeling like it’s gonna bend in half.
That “tank” feeling is exactly why I leaned toward Marvin too—just seems like less flex, especially on bigger windows. But you’re dead on about install making or breaking it. When I swapped out the old sashes in my 60s split-level, I spent more time shimming and sealing than actually setting the window. Even a tiny gap can undo all that quality. Honestly, if you’re handy, double-checking the squareness and using good spray foam makes a world of difference... doesn’t matter how fancy the window is if there’s air sneaking around it.
Yeah, it’s wild how much the install can make or break things. I went with Marvin for my upstairs last winter, mostly because I wanted that solid frame feel—less flex like you said, and they just seemed beefier. But honestly, even with the higher price tag, if the gaps aren’t sealed right, you’ll still feel a draft. I learned the hard way with one window where I got lazy on the shims... had to go back and redo it after noticing cold air sneaking in. Spray foam’s great, but I’d say don’t overdo it either or you’ll bow the jambs. It’s a balance.
Spray foam’s great, but I’d say don’t overdo it either or you’ll bow the jambs. It’s a balance.
Yeah, I totally messed up my first window with too much foam. It looked fine at first, but then I noticed the sash was sticking and realized the frame had actually warped a bit. Had to pull it out and start over. Since then, I just use a little and check for drafts with a candle before calling it done. Marvin does feel sturdier, but install’s everything.
Interesting you mention the candle trick—I’ve found that works, but sometimes it misses micro-leaks near the corners or in weird framing spots. Have you ever tried the low-expansion foam specifically made for windows and doors? It’s pricier, but I think it’s worth it to avoid the warping issue you ran into. Also, with Marvin, I’ve noticed the frames hold up better to a little more pressure, but I still wouldn’t push my luck. Curious if anyone’s had better luck with backer rod and caulk instead of foam for those tight installs...
I’ve actually had mixed results with backer rod and caulk, especially on the older framing in my 70s split-level. The foam feels more reliable for the weird gaps, but it’s definitely messier and can be overkill if you’re not careful. Has anyone dealt with the Integrity sashes swelling a bit in humid months? I’m wondering if that’s a caulking issue or just the material reacting to weather.
Honestly, I wouldn’t pin the swelling just on caulking. The old Integrity sashes are fiberglass, and while they’re more stable than wood, they’re not immune to humidity swings—especially in a 70s frame that’s probably shifted over time. I’ve seen more issues from the frame itself being out-of-square or the sash weatherstripping getting compressed. Caulk can help with drafts, but it won’t fix material movement. If you’re seeing binding in summer, check the reveal all the way around the sash first, then look at your weatherstripping before blaming the caulk job. Foam’s great for weird gaps but yeah, it can get messy if you’re not careful... I usually stick with backer rod and high-quality sealant unless there’s a real monster gap.
That’s a solid take on the caulking—seen plenty of folks blame it when the real culprit is frame movement or old weatherstripping. I’ve worked on a bunch of houses from the 60s and 70s, and those frames rarely stay square after decades of settling. Even with fiberglass sashes, you’ll get some seasonal expansion, especially if the frame’s already tweaked. I usually pull the stops and measure the diagonals before doing anything else, just to see how far out things are.
Backer rod and high-quality sealant have saved me more than once, but like you said, foam can get out of hand fast. Had a job where someone went wild with spray foam—took longer to clean it up than to actually fix the window.
Curious, for those who’ve swapped out old Integrity for new Marvin, did you notice any difference in how they handle these frame quirks? I’ve heard the new units are a bit more forgiving, but haven’t installed enough to say for sure.
I swapped out a couple old Integrity units for the newer Marvin ones last winter. Honestly, I did notice a bit more play with the new Marvins—seemed to handle my less-than-perfect frames without as much swearing. Still had to shim one side more than I liked, but at least the sashes didn’t bind up every time the temp dropped. Not magic, but definitely less headache than wrestling with the old ones and a caulk gun.
Had the same kind of experience with Marvin—swapped out three old Integrity windows in my 90s ranch last fall. I get what you mean about the play.
That’s exactly it. My frames were anything but square, and the Marvins just slid in with a lot less fighting than I expected. Didn’t need to bust out the multi-tool or curse at warped jambs for once.“seemed to handle my less-than-perfect frames without as much swearing”
Only thing that bugged me was the price jump compared to Integrity. Not sure if it’s all in the hardware or just the name, but my wallet felt it. Still, I’ll take that over dealing with sticky sashes every winter. Haven’t noticed any drafts yet, even after a couple cold snaps, so I’m calling it a win for now.
Wouldn’t say they’re perfect, but way less hassle than the old ones, that’s for sure.