Natural slate is quarried stone, and a properly installed natural slate roof lasts a century or more — the stone itself outlives the house. Synthetic slate is a manufactured panel made to imitate it: lighter, easier on the structure, and, in our published words, it won't outlive you. The trade is lifespan and authenticity against weight, and the right answer depends on the building.
What each one actually is
Natural slate is split stone, laid course by course, with copper flashing that will outlast the stone itself. Its color is the stone's own — there is no coating and no factory finish to fade. Synthetic slate is a manufactured panel, molded and colored to resemble stone and hung in uniform courses at much less weight.
Lifespan is the whole argument
A century or more, against a panel that won't outlive you. That is the comparison in one line. On a slate roof, the fasteners and flashing get attention along the way; the stone does not wear out. We have done the hundred-year math elsewhere — one slate roof against repeated tear-offs and trips to the landfill — and it is worth reading before you decide.
Weight, and the buildings that can't carry stone
Here is the honest case for synthetic: slate is heavy, and some structures were never built to carry it. On a building whose framing can't take stone without reinforcement, a lighter roof may be the practical answer. We will tell you straight which side of that line your building sits on. That is a first-visit question, and it deserves a straight answer, not a sales pitch.
On a historic building, there is no contest
Restoration means matching original materials and methods. A historic roof was stone. A manufactured panel cannot match the original profiles, the variation, or the century of service — and on a landmark, authenticity is not decoration. It is the assignment. Our historic restoration guide explains how that standard is applied.
What about cost?
Synthetic exists because it is the lighter, lower-first-cost path onto a roof — that much is plain. Beyond that, we don't publish figures for either material, and you should be careful with anyone who does: the cost of a slate roof depends on the stone, the complexity, and the size of the job, and material prices move. We price every job individually and tell you straight what is driving the number.
— Gary Shank