What are those snow stopper things on slate roofs called? I can’t remember. Are they required or just a good stinking idea.
Here in Canada we call them Avalanche guards
I call them ice cleats or ice guards. We don’t get as much snow as Roy, around here the ice is the only real concern.
Snow guards, avalanche preventers, avalanche guards… just can’t call them snow preventers!
We always called them bird stands. Cut down trees and build houses, a bird has to land somewhere
They are a safety feature. Snow sliding off a roof can cause a lot of damage (lots of deck handrails demolished) or serious or fatal injury.
Covered in the Mastering Roof Inspection series here.
Most recognized here is avalanche guards!
Yes, ‘Avalanche guards’. Not required here.
Snow guards. I’m not really a fan unless they have been incorporated into the structure. Although. the stick on type are nice because they are self-uninstalling! Simply install, then wait until spring and pick them out of the snowbank. 
Wet snow can weigh 25 lbs. per cu. ft. Imagine what a roof full of snow 2 feet thick can do to you when the whole roof breaks free and slides, slamming into your upper body and pinning you against a handrail a moment before snapping it off and blasting you and the handrail off the deck, onto the ground below and burying you.
Doesn’t matter whether they’re required. If you’re inspecting a house where roof avalanches are possible, you should recommend that they be installed. This includes slate, tile and especially metal roofs.
Thanks for the info. Things I’m glad I don’t have to think about (that and no basement)