Adding more soffit vents is usually a solid move, especially with a low pitch roof from that era. I’ve seen a lot of homes from the 70s where attic ventilation was an afterthought, and even the best roofing materials can’t really compensate if warm air’s getting trapped up top. Ice damming tends to show up right at those eaves when things aren’t breathing enough.
One thing I’d suggest—before you start cutting new vents—is to double check that your current soffit vents aren’t blocked by insulation or paint. Sometimes they’re technically “there,” but not actually doing anything. If you’ve got fiberglass batts pushed right up against the eaves, air can’t flow in. Baffles (also called vent chutes) might help keep a path open from the soffit into the attic.
If you do add more vents, just make sure there’s a balance between intake (soffit) and exhaust (ridge or roof vents). Too much of one without the other doesn’t really help. And yeah, shallow roofs are always tricky… but you’re definitely on the right track thinking about ventilation instead of just blaming the shingles or underlayment.
- Totally agree on checking for blocked soffit vents before spending anything. I found mine painted shut—thanks, previous owners.
- Noticed the insulation was stuffed right up to the eaves too. Pulled it back and tossed in baffles. Cheap fix, just took some crawling.
- I’d add: don’t go overboard with vents unless you actually need them. More holes = more places for critters if you’re not careful.
- My roof’s only a 3/12 pitch, so ice dams are a pain every year. Ventilation helped, but I still get some melt/freeze at the edges. Not perfect, but better than replacing shingles every few years...
Painted shut soffits are a classic—seems like every house I’ve worked on has some “creative” handiwork from the last owner. I’ve seen folks try to fix ice dams by just slapping more vents up there, but honestly, too many holes and you’re basically inviting squirrels to move in rent-free. Not worth the headache.
On low-pitch roofs like 3/12, you’re always fighting an uphill battle with ice dams. Even with good airflow, if your attic’s a bit warmer than it should be, you’ll still get that melt/freeze cycle at the edges. I’ve had people swear by heat cables, but those are more of a band-aid than a real fix. Sometimes it’s just about managing expectations—unless you want to rip off the whole roof and start over, you’re probably going to see some icicles now and then.
One thing I’d add: check for wind-driven rain leaks around vents and flashing after storms. Sometimes it’s not even the ice—it’s water sneaking in sideways when the wind’s howling. Learned that one the hard way after a nor’easter last year...
That’s interesting about the wind-driven rain—never really thought about that as a separate issue from ice dams. I’ve mostly been focused on attic insulation and sealing up gaps, but now I’m wondering if I should be looking at my flashing and vent boots more closely after storms. My roof’s only a 4/12 pitch, so not much steeper than what you mentioned, and I do get some icicles along the north side every winter.
I’ve always hesitated to add more vents because of the critter problem (had a squirrel in the attic once, never again), but I’m not sure if my current setup is actually enough. Is there a way to tell if you’ve got the right balance between ventilation and keeping pests out, short of just waiting for problems? And for those who’ve tried heat cables—did you notice any spike in your electric bill, or is it pretty negligible? I’m trying to keep costs down but also avoid bigger repairs down the line...
I’ve always hesitated to add more vents because of the critter problem (had a squirrel in the attic once, never again), but I’m not sure if my current setup is actually enough. Is there a way to tell if you’ve got the right balance between ventilation and keeping pests out, short of just waiting for problems?
Honestly, I wouldn’t let the critter thing stop you from adding vents if your attic’s running too warm or damp. There are vent screens and baffles made specifically to keep squirrels and birds out—just gotta make sure they’re installed tight. I’ve seen more issues from poor ventilation (mold, warped sheathing) than from animals getting in, at least around here.
On heat cables: they do work for ice dams, but I noticed a definite bump in my electric bill last winter when I ran them during every cold snap. Not huge, but not nothing either—maybe $20-30/month depending on how much cable you use and how cold it gets. If you’re only getting icicles on one side, might be worth looking at air leaks or insulation above that area before going straight to cables.
4/12 isn’t super steep, so water can linger longer after storms. Flashing and vent boots are definitely worth checking after heavy wind or rain—sometimes leaks show up weeks later as stains inside.
