One of the more interesting things about some of the older buildings I saw in Norway was the fact that they had wooden roofs. Not shingle roofs, but roofs made of overlapping planks laid perpendicular to the roof ridge. Usually they are made out of 1″ pine. These are quite common in historic buildings, such as medieval churches, some museum buildings and in open air museums. These roofs were classically constructed in the manner shown in the photo below, or in a complete-overlap to produce a flat roof. The roofs were nailed down using iron nails treated with linseed oil (to make them weatherproof), and the roofs coated in pine tar, which provides for a good water-repellent coating. The top row of boards on the roof plank need to be laid so that the curve of the annual rings facing up, while the bottom row of this convexity must be directed downward.
I wonder how well these roofs would work here in Canada?
P.S. Wondering where to get pine tar in Canada? Try Swede Paint Enterprises.