The short answer
Atlas Pinnacle Impact is UL 2218 Class 4 with a 130 mph wind rating, and StormMaster Shake is Class 4 with a 150 mph rating and a Core4 premium polymer modified blend. The genuine differentiator is the algae coverage: Atlas offers a lifetime algae warranty backed by Scotchgard Protector by 3M, which is the strongest algae position among the major manufacturers.
Verified specifications
| Item | What Atlas publishes |
|---|---|
| Pinnacle Impact | UL 2218 Class 4, 130 mph wind |
| StormMaster Shake | UL 2218 Class 4, 150 mph wind, Core4 premium polymer modified blend |
| Algae warranty | Lifetime, backed by Scotchgard Protector by 3M |
| Our status | RoadRunner is Atlas certified |
Figures above come from Atlas published product and warranty documents. Specifications change, so confirm against the current data sheet for the exact product before you sign a contract.
What this means for a roof here
Impact class earns an insurance credit, and in the Hill Country that credit compounds every year you own the house. What it does not do is make a roof hail proof. Manufacturers generally do not warrant shingles against hail damage, and a 2025 study by the Insurance Institute for Business and Home Safety found impact-resistant shingles performed only slightly better than conventional shingles against cumulative granule loss from repeated small hail. Buy the class for the insurance credit and the margin against large stones, not for immunity.
The other thing worth noticing across every brand on this page is how often the headline rating depends on the system rather than the shingle. Wind ratings and warranty tiers routinely require that manufacturer's starter, underlayment and ridge cap. A shingle installed without its specified components does not carry its advertised performance, and that gap is where cheap bids come from.
