NEED ADVICE ON REPLACING AN OLD LEAKY ROOF
Yeah, those old rafters can really throw you for a loop. I’ve run into “mystery wood” more times than I care to admit—sometimes it’s like the house is held together by sheer willpower and nails from three different decades. I get wanting to go green, but if the structure’s already sagging, lightweight is usually safer. One thing I’d add: check for hidden water damage before you start. Sometimes what looks like a simple leak turns out to be rot in spots you’d never expect... Learned that the hard way on a 1915 cottage.
Sometimes what looks like a simple leak turns out to be rot in spots you’d never expect... Learned that the hard way on a 1915 cottage.
Totally get this—had a similar surprise in my attic last year. A couple extra things I’d keep in mind:
- Don’t just check rafters—look at the ends where they meet the walls. That’s where I found hidden rot.
- If you’re thinking about insulation upgrades, now’s the time. Way easier with the roof open.
- Lightweight roofing is smart, but double-check your local code if you’re switching materials. Some places are weird about it.
It’s a pain, but catching those issues early saves a ton of hassle down the road.
Honestly, I see people skip the inspection at the eaves all the time—big mistake, especially in older homes. The transition points, where roof meets wall, are such a magnet for hidden issues. And yeah, insulation is a no-brainer if you’ve got things opened up. Curious—has anyone here had success with spray foam in these older structures? I’ve seen it go both ways, depending on ventilation and how much original wood you’re dealing with. Sometimes it solves more problems than it creates, but not always.
Curious—has anyone here had success with spray foam in these older structures? I’ve seen it go both ways, depending on ventilation and how much original wood you’re dealing with. Sometimes it solves more problems than it creates, but not always.
I’ve been down this road a few times, and I’ll say—spray foam is a double-edged sword in older homes. It’s tempting because of the airtight seal and the R-value bump, but if you’re not careful about moisture management, you can end up with rot or mold issues that are way worse than the original leaks. The eaves are notorious for hidden rot, especially where old flashing has failed or insulation was never properly installed.
In my experience, spray foam works best when you’re absolutely certain there’s no existing moisture trapped in the wood. If you’ve got any doubt, it’s worth pulling back the sheathing and checking for soft spots or discoloration. I’ve seen people skip this step and regret it later—once that foam is in, you’re not getting it out without a fight.
Ventilation is another big one. In some of these older homes, the original design relied on a lot more airflow than modern builds. If you seal everything up tight with foam but don’t address ridge or soffit venting, you can create a whole new set of problems. I’ve had good luck pairing closed-cell spray foam with a well-designed venting system, but it takes some planning.
One thing I’d add: if you’re dealing with any historic woodwork or want to preserve original beams, be cautious. Spray foam can make future repairs tricky and sometimes damages finishes if there’s any leakage during application.
Long story short—spray foam can be great, but only if you’re methodical about prep and ventilation. Otherwise, you might just be trading one headache for another.
I get where you’re coming from, but I’ve actually had better luck just sticking with traditional vented insulation and making sure the roof deck is solid. Maybe it’s just my old place, but I found that keeping things “breathable” helped avoid those hidden moisture traps you mentioned. Ever notice how some of these old houses seem to do better when you let them breathe a little? I get the appeal of spray foam, but sometimes I wonder if we’re overengineering what used to work fine for decades. Anyone else feel like the “airtight” approach can backfire in these quirky old structures?
