Those tricky dormer valleys are notorious for giving folks headaches. I’ve lost count of how many times I’ve seen someone throw everything at a cold corner and still end up with a drip in March. Heat cables aren’t glamorous, but sometimes they’re the only thing that keeps the peace. I do like metal roofs for snow country, but you nailed it—if the insulation and airflow underneath aren’t dialed in, you can still get those ice dams. Had a client last year who thought switching to metal would solve everything, but we ended up chasing attic moisture instead. It’s all about finding what works for your specific setup... sometimes that means living with a few wires on the eaves.
“Had a client last year who thought switching to metal would solve everything, but we ended up chasing attic moisture instead.”
That part hits home. I swapped my old shingles for standing seam metal thinking it’d be the end of ice dams, but the first winter after, I still had icicles hanging off the valleys. Turns out, my insulation wasn’t nearly as tight as I thought and the soffit vents were half-blocked with old insulation. Here’s what actually helped:
1. Pulled back the insulation at the eaves so air could flow from soffit to ridge.
2. Added baffles to keep that path open.
3. Topped up the attic insulation—nothing fancy, just more blown-in cellulose.
4. Only after that did I run heat cables in one stubborn valley where snow always piles up.
Honestly, heat cables are a band-aid if you haven’t fixed airflow and insulation first. But sometimes you just need them for peace of mind, especially on those weird roof angles or dormers where snow loves to camp out. Metal’s great for shedding snow, but it won’t fix a warm attic by itself... learned that the hard way.
