I've had similar experiences with zinc strips—sometimes they work, sometimes they're just decoration. Honestly, if moss is a big issue, choosing a tile brand with built-in algae resistance like Eagle or Boral might save you headaches down the road.
Totally agree about the zinc strips—they're hit or miss in my experience too. I've seen roofs where they've done wonders, and others where the moss just laughed them off. Honestly, Eagle and Boral are solid choices if algae resistance is a priority. Another brand worth mentioning is Ludowici—they're pricier, but their clay tiles have great natural resistance to algae and moss. Installed a Ludowici roof about 7 years ago on a heavily shaded property, and it's still looking sharp with minimal maintenance.
One thing to keep in mind though, no matter how good the tile brand is, proper installation and ventilation play huge roles in preventing algae growth. Seen plenty of expensive tiles fail prematurely because the attic wasn't vented properly or the installation was rushed. So whichever brand you choose, make sure your installer knows their stuff...makes a world of difference down the road.
Couldn't agree more about ventilation—seen a few roofs with top-tier tiles that still got mossy because the attic was basically a sauna. Another brand I've had good luck with is MCA Clay Roof Tile; installed one about 5 yrs ago, still looks great even under heavy tree cover.
Ventilation really is the unsung hero of roofing. Had a neighbor who splurged on some premium tiles, thinking they'd solve all his roof woes. But he skipped upgrading the attic vents, and within two years, moss was having a full-on party up there. MCA tiles are solid though—my cousin put them on his place near Portland, surrounded by pines and constant drizzle, and they're holding up impressively well. Good to hear they're working out for others too.
"Ventilation really is the unsung hero of roofing."
Couldn't agree more—ventilation is like the bass player in a band. Nobody notices until it's missing, then suddenly everything sounds off. Had a similar experience myself a while back. Thought I'd nailed it by choosing some top-tier tiles (Eagle Roofing, if anyone's curious), but neglected the attic airflow situation. Big mistake... ended up with condensation issues that had me scratching my head for months.
Glad to hear MCA tiles are holding up nicely in Portland—if they survive that dampness and those pines, that's a solid endorsement right there. I've heard good things about Ludowici too, though they're pricier and heavier, so you'd wanna double-check your roof structure before diving in. Anyway, lesson learned: don't underestimate the power of good vents. Tiles can only do so much.
