Stone-coated steel (the category many national lead-gen installers sell) and Interlock's aluminum interlocking system are both premium metal roofs. Here's how they differ.
| Factor | Interlock Aluminum | Stone-Coated Steel |
|---|---|---|
| Base metal | Aluminum (rust-proof) | Steel (coating-dependent) |
| Finish | Baked multi-coat | Bonded stone granules |
| Corrosion in salt air | Excellent | Risk at cut edges over time |
| Weight | Lightweight | Heavier |
| Granule loss | None (no granules) | Possible over decades |
| Warranty | 50-yr transferable | Varies by brand |
Which holds up better in New England?
For coastal and high-humidity exposure, aluminum's rust-proof base is the conservative long-term choice. Stone-coated steel performs well too, but its longevity hinges on the steel's coating and on the stone layer staying bonded.
