<p>A roofing tile installation system includes spaced rows of installation strips each having an elongated base to which is attached a plurality of spaced apart hooks. The hooks are formed with a profile that engages and presses on underlying tiles and that grips and hooks around the lower edge of an overlying tile. Each tile is positioned and held laterally between a pair of hooks and held vertically on the slope of a roof by a single hook. An improved weatherproofing system includes a second layer of water resistive material which protects an underlying layer of plastic weatherproofing material against exposure to sunlight and erosion from wind and rain.</p>
