“You end up chasing leaks around every little gusset plate and web intersection.”
That’s been my experience too. Trusses are great for material efficiency and they make the framing process a lot faster, but air sealing is a real pain. I spent a couple weekends last winter crawling around with cans of foam and a caulk gun, trying to get every joint. Still ended up with some cold spots, especially near the eaves. It’s just tough to get it perfect when there are so many connections.
I agree that rafters make it easier to get a continuous air barrier—especially if you’re doing something like rigid foam or even just a well-installed membrane. But like you said, losing attic storage is a big deal for some of us. I’ve got boxes of holiday decorations and old tax records up there... not sure where else they’d go.
The rigid foam between webs trick is clever, but honestly, I priced it out for my place and between the cost of the foam and all the cutting/fitting, it wasn’t much cheaper than just hiring someone to do open-cell spray foam (which I couldn’t really afford either). Plus, as you mentioned, it’s tedious work. My neighbor did it and said he was still finding little gaps months later.
One thing that helped me was using “flash and batt”—a thin layer of closed-cell spray foam just to seal things up, then filling in with batts. Not perfect, but better than just batts alone. Still not cheap though.
I think you nailed it with this:
That’s where I landed too. If you’re in a climate where moisture is a big concern (I’m in the Midwest—lots of freeze/thaw), then yeah, more attention to detail pays off. But for most folks on a budget, getting 90% there is still way better than nothing.“Sometimes ‘good enough’ really is good enough—especially if you’re not ready to shell out for full spray foam everywhere.”
If I ever redo my roof structure, I might lean toward rafters just for the simplicity of air sealing... but until then, I’ll keep patching up those truss leaks as best I can.
That’s pretty much how it went for me too—trusses made the build go faster, but sealing every little spot was a headache. I tried using tape on the bigger seams before foaming, which helped a bit, but it’s still not perfect. If I had to do it over, I’d probably budget more time for air sealing from the start. The attic storage is a must for us though... can’t imagine where all our camping gear would go otherwise.
Trusses are a real time-saver, but yeah, air sealing is where the fun ends and the cursing begins. I’ve found that if you go overboard with the spray foam, you end up with a sticky mess and still miss those sneaky gaps. One trick I picked up—use a flashlight at night from inside the attic, have someone outside look for light leaks. Not perfect, but it catches stuff you’d never see otherwise. And I hear you on attic storage... my fishing rods would be living in the bathtub if I didn’t have that space.
Trusses are a real time-saver, but yeah, air sealing is where the fun ends and the cursing begins. I’ve found that if you go overboard with the spray foam, you end up with a sticky mess and still...
That flashlight trick is a classic—I've used it on more than a few inspections, and it really does catch the oddball spots you’d never think to check. But I’ll throw in one more: try using a smoke pencil (or even incense) on a windy day. You’d be amazed at how a little draft will show you exactly where the air is sneaking through.
About attic storage, though—trusses are handy, but I’ve seen folks cut out webs to make more space, which is a huge structural risk. If you need storage, stick with designs that allow for it from the start. I’ve seen way too many “creative” solutions turn into sagging roofs down the line.
I’ve seen folks cut out webs to make more space, which is a huge structural risk.
- Cutting truss webs is asking for trouble—seen too many roofs fail after storms because of this.
- If you want storage, plan for it from day one. Attic trusses or stick framing with rafters are better options.
- Rafters give you more flexibility but take longer and cost more.
- Trusses are fast and strong, but modifying them later is a nightmare.
- After a big wind event, the first thing I check is whether someone’s “customized” their trusses... never ends well.