A fire protection system is provided for a space having a pitched roof constructed of structural members extending from a ridgeline to an eave, with respective channels therebetween. A first row of sprinklers is mounted to a first branch line extending generally parallel to the ridgeline. Each sprinkler is positioned within a respective channel, with consecutive sprinklers spaced apart having no less than one, and no more than five, channels therebetween. A second row of sprinklers, downslope from the first row, is mounted to a second branch line extending generally parallel to the first branch line. Each sprinkler thereof is positioned within a respective channel, with consecutive second row sprinklers spaced apart as in the first row. Each second row sprinkler is also placed within a different channel from each first row sprinkler. A farthest number of channels between a first row sprinkler and a second row sprinkler is three.