Wind, snow and older roofs on the west side
Wind off the foothills can peel back shingles along the edges and ridge, and it can drive rain sideways under flashing that looked fine in calm weather. Snow loads vary with each storm, and wet spring snow can sit heavily on a roof. Sun then melts it by day and refreezes it at night, which is how ice builds up along eaves.
Major routes such as 6th Avenue, Colfax and C-470 carry the traffic, but for a roofer the local factor is the older housing stock, with its additions, patches and aged underlayment.
