Synthetic Slate vs. Metal Slate Roofing
Quick answer
Synthetic slate is molded from polymer or composite to mimic slate; metal slate is stamped from aluminum or steel. Both weigh far less than real slate and cost less. Metal slate wins on fire resistance, hail impact, and lifespan; synthetic slate can look thicker and more slate-like up close. The "fake slate" people search for is usually one of these two.
What is the difference between synthetic slate and metal slate?
It is a difference of material. Synthetic slate (also called composite or polymer slate) is molded from plastic, rubber, or a composite blend, often with a thick, dimensional profile that mimics a hand-cut slate tile. Metal slate is stamped from aluminum or steel sheet and finished in slate colors. Both are lightweight, slate-look alternatives to quarried stone — and both are what people mean when they search for "fake slate" — but polymer and metal age very differently, which is where the real decision lies.
Which is more durable — synthetic or metal slate?
Metal slate generally has the edge on the toughest measures. Aluminum metal slate is non-combustible and earns Class A fire resistance, carries a UL 2218 Class 4 hail rating, does not degrade under UV, and lasts 50+ years — and it is fully recyclable. Synthetic slate resists impact well and looks convincingly thick, but its polymer base can fade, chalk, or become brittle under decades of UV exposure, and many synthetic products are combustible unless specially treated. For fire zones, severe hail, and maximum lifespan, metal slate is the more robust choice.
What is the "fake slate" roof people ask about?
"Fake slate" is simply how people describe any slate-look alternative to real stone — it is not one specific product. In practice it refers to either synthetic/composite slate (molded polymer) or metal slate (stamped aluminum or steel like Interlock's). Both deliver the slate appearance at a fraction of real slate's weight and cost. So when you see "fake slate roof" in a search or a listing, the useful next question is which material it is, because that determines its fire rating, hail resistance, and lifespan.
Which should you choose?
Choose metal slate if fire resistance, hail performance, longevity, recyclability, and an energy-saving reflective finish are priorities — which makes it the stronger all-around pick, and the right one for wildfire and hail-prone regions. Synthetic slate can appeal if you want a very thick, deeply dimensional tile look up close and fire and UV are lesser concerns for your location. Interlock's slate profile is aluminum metal slate, pairing the authentic look with metal's fire, impact, and lifetime advantages.
Frequently Asked Questions
Can you walk on a synthetic or metal slate roof?
Both handle foot traffic far better than brittle natural slate, which cracks underfoot. Metal slate flexes and is walkable with care (step in supported areas, ideally leave it to a trained installer), and synthetic slate is also walkable. Neither shatters the way real slate can, which is one shared advantage over quarried stone.
Does synthetic slate fade over time?
It can. Because synthetic slate is polymer-based, decades of UV exposure can cause some fading, chalking, or brittleness depending on the product. Metal slate's baked-on finish is engineered to resist fading for decades, and the aluminum beneath never degrades — an advantage in long-term color retention.
Is metal slate fireproof?
Aluminum metal slate is non-combustible and achieves Class A fire resistance, the highest rating, making it an excellent choice in wildfire-prone areas. Many synthetic slate products are combustible unless specially formulated, so fire rating is one of the clearest reasons to favor metal in fire country.
Sources
- UL 2218 — Impact Resistance of Prepared Roof Covering Materials
- UL 790 / ASTM E108 — Class A fire testing for roof coverings
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Last reviewed 2026-07-12 · Reviewed by Scott Plumptree, Director of Marketing