Toronto roofing will walk along the ridge to get from one place to another, and light gauge metals like aluminum will buckle under the weight of a person. This is why ventilated ridges aren’t recommended on slate roofs. The ventilation should be out the gable ends of the roof, or out roof vents, but not out the ridges if it can be avoided. When a person works on slate roofs day in and day out, hell cringe when he sees a slate roof with aluminum ventilated ridge, because he knows how difficult it will he to get around on the roof without damaging the ridge if the roof needs work. Although ventilated ridge will perform well on a slate roof, it can interfere with the routine upkeep and maintenance of the roof by obstructing hook ladders as well as roofers. Slate roofs are made to last for centuries, and by design they should allow for routine maintenance and upkeep. People who put unusual ridges on slate roofs usually aren’t thinking about having to work on the roof over the next century.