The use of Spikes & Ferrules is an old method of hanging gutters to a plum fascia. Spikes should be nailed through the fascia board and into a rafter tail for proper support and should be spaced according to the spacing of the rafter tails. Spikes are driven through the face of the gutter and the ferrule is a copper sleeve that sits inside the gutter and acts as a spacer so the nail does not get over driven.