What it is
Steel panels coated with stone granules, stamped to resemble asphalt shingle, wood shake or clay tile. The panels overlap and use open channels underneath to carry away water that gets past the surface. It is a system that manages water after it enters, rather than keeping it out at the surface.
Why people choose it
The look. It reads as a conventional roof from the street, the granule surface is quiet and matte, and it carries good wind and fire ratings. Tilcor's products, which we install, are well made for what they are.
Where I am cautious, and why
This is where things usually go wrong. Because water is expected to get under the panels, the roof relies heavily on the underlayment and on the flashing details to stay dry over the long term. That is more places for water to find a path over thirty or forty years than a system that stops it at the surface. Pitch has to be 3/12 or steeper. And the granule surface, while durable, is not a painted PVDF finish — it weathers differently.
I install stone-coated steel when a homeowner has looked at the tradeoff and the appearance matters enough to them. I do not present it as equivalent to a mechanically seamed standing seam or a four-side interlocking shingle, because in how they handle water, it is not.
What it does well
Familiar appearance with steel underneath. Lighter than tile. Good impact and fire ratings. Lower upfront cost than some interlocking shingles.
Who it fits
Homeowners who want the look of shake or tile above all, on a roof at 3/12 or steeper with simple geometry, and who are comfortable with a system that depends on its underlayment and detailing.
Who it does not fit
If your priority is the fewest possible ways for water to get in over the life of the roof, look at standing seam or an interlocking shingle first. If the roof is low-pitched or has a lot of valleys and dead ends, I would steer you away.
Keeping water out is more reliable than managing it later. That is the whole of my opinion on this system.
