How-to-install-fascia-and-gutters, www.metalroofingonline.com.au install metal fascia and guttering.. The type of heat tape used on roofs and gutters to prevent ice buildup is properly called heat cable. the term heat tape refers to another product—an insulated electrical wire applied to water pipes to keep them from freezing and bursting. heat cable is a similar product, but it is designed for installation on the edge of your home's roof, near the eaves., to install gutters, have the gutters slope downward toward the downspout so they work properly. if the fascia board you're installing them on is longer than 35 feet, have the gutters slope from the center to each end. or, if the fascia board is less than 35 feet long, have the gutter slope from one end of the board to the other.