Man, old plaster is always a wild card. I’ve had spots where it just crumbled if I looked at it funny. Joint compound works but you kinda gotta feather it out way wider than you’d think, or it’ll show every bump. Sometimes I’ll use setting-type mud (like Easy Sand) for the first coat since it sets up harder and doesn’t shrink as much, then finish with regular joint compound. Still, matching that old texture is never perfect… I usually just call it “character.”
That’s definitely the reality with old plaster—sometimes it’s solid, other times it just falls apart if you touch it. I’ve run into that a lot when pulling out original windows. Even with careful demo, the plaster can crack or crumble around the opening, especially on exterior walls. I usually end up doing a pretty wide patch with setting-type compound too, just to stabilize things before finishing. Matching that lath-and-plaster texture is tough—sometimes I’ll use a dry brush or sponge to try and mimic the old look, but it’s rarely perfect. At a certain point, I figure a little imperfection just fits with an older house.
Matching that lath-and-plaster texture is tough—sometimes I’ll use a dry brush or sponge to try and mimic the old look, but it’s rarely perfect.
Totally get what you mean about the texture. I’ve tried a few different things—sometimes even pressing a crumpled paper towel into the mud while it’s setting. Still never quite matches. Did you ever find a way to keep the edges from cracking later on? I’ve noticed my wider patches sometimes want to hairline after a season or two, especially where old meets new. Maybe it’s just the house settling, or maybe I’m missing something with the prep.
That cracking at the edges drives me nuts too—it’s almost always where the new joint compound meets the old stuff. In my experience, mesh tape helps, but honestly, sometimes nothing stops those hairlines if the wall keeps moving. I’ve even tried a flexible caulk under the top coat in spots that flex a lot, which worked better than I expected. Prep is huge, though. If there’s dust or the old plaster’s chalky, it just won’t bond right, no matter what tricks you try.
Prep is huge, though. If there’s dust or the old plaster’s chalky, it just won’t bond right, no matter what tricks you try.
I get what you’re saying about prep, but I’ve actually had a bit of luck with bonding agents when the old plaster’s super chalky. There’s this stuff called Plaster Weld that’s saved me a few times—definitely not foolproof, but it gave the joint compound something to grab onto in spots where I just couldn’t get all the dust out. Not saying it’s magic, but it might be worth a shot if you haven’t tried it.
On the mesh tape vs. paper tape debate, I know a lot of folks swear by mesh for cracks, but I’ve had more luck with paper tape and a setting-type compound (like Durabond). Mesh always seems to crack on me eventually, especially if there’s any movement. Maybe it’s just my old house settling more than most.
Funny enough, I’ve never tried the flexible caulk trick under the top coat—does it actually stay hidden, or do you notice it over time?
I hear you on the bonding agents—Plaster Weld’s definitely helped me out in a pinch, especially on those old crumbly walls. Still, I’ve run into situations where even the best bonding agent just wasn’t enough if the surface was too far gone. Sometimes, you gotta bite the bullet and skim a little deeper or even patch in some new board. Guess it depends how much time you want to spend chasing that perfect bond.
On the tape debate, I actually lean the other way—mesh has saved my bacon with hairline cracks in spots that flex a lot, like around window frames. Maybe it’s just luck, or maybe it’s how I’m bedding it in, but paper tape always seemed to bubble or lift on me unless I really nailed the mud consistency.
As for that caulk trick, I’ve tried it behind top coats on ceiling cracks. If you feather it out wide enough, it stays hidden, but if you cheap out on mud or sanding, you’ll see a faint line when the light hits just right. Not perfect, but better than chasing the same crack every spring...
On the tape debate, I actually lean the other way—mesh has saved my bacon with hairline cracks in spots that flex a lot, like around window frames.
Funny, I’ve had the opposite luck—mesh always seems to crack on me after a winter or two, especially in those old plaster walls. Maybe it’s the temperature swings here, or maybe I’m just cursed. About swapping out windows yourself, though... did you run into any surprises once you pulled the trim off? I’ve heard horror stories about hidden rot or weird framing from past renovations. That’s what’s got me hesitating.
Pulled the trim off one of mine last fall and, yeah, found some sketchy framing—looked like someone just made it up as they went. Had to add blocking and foam to stop drafts. Didn’t hit any serious rot, but honestly, you never know till you’re in there. If your place is older, I’d budget extra time just in case... those surprises are almost a given.
That’s been my experience too—once you start pulling things apart, you’re at the mercy of whatever shortcuts the last person took. I swapped out a couple of windows in my 1950s place last spring, and it was clear some previous owner wasn’t too worried about following code. Found random bits of 2x4s acting as “headers” and a whole section where the insulation was just newspaper stuffed behind the jamb. Ended up re-framing almost half the opening to get it square enough for the new window to sit right.
If you’re dealing with anything pre-1980s, I’d say expect at least some degree of wonky framing or missing insulation. It’s not always rot, but you’ll probably need to shore up something—blocking, shims, or even new sills if there’s water damage. And like you said, air leaks are almost guaranteed. I used low-expansion foam around the perimeter and then backer rod where things were really uneven; made a huge difference in drafts.
One thing I’d add: window sizing on older houses can be inconsistent. Even if your replacement is “standard,” be ready to modify the rough opening or do extra trim work inside and out. I had to custom order one window because nothing off-the-shelf would fit without major surgery.
It’s definitely a hassle, but if you’re comfortable with basic framing and have the patience for some curveballs, it’s doable. Just don’t underestimate the time investment—what looks like a weekend job can easily stretch into a week if you hit unexpected issues, especially if you have to let framing dry out or wait for special order parts.
All in all, I’d say it’s worth it for the energy savings and comfort, but only if you’re ready for some surprises behind those trims.
what looks like a weekend job can easily stretch into a week if you hit unexpected issues
That’s the truth—there’s always some curveball hiding behind old trim. But honestly, getting rid of those air leaks and weird “insulation” (if you can call crumpled newspaper insulation) pays off big time. The comfort difference is real. I’ll admit, it’s definitely not a fast project, but the lower energy bills and fewer drafts make all the hassle worthwhile in the long run.