Slate Roof $22,560 or $14.10 per ft. 2 Quote consists of mounting a brand-new natural slate roof, as well as underlayment, all blinking, on a cattle ranch style 1,600 sq.ft. Note, that slate is the heaviest roof material that calls for structural support. On numerous houses it is not possible to install a new slate roof at all. Getting rid of old timber roof shingles or shakes will certainly set you back $1.20-- $1.50 per foot.