Quick Answer
A Class 4 roof has passed the highest level of the UL 2218 impact test, where a 2-inch steel ball is dropped onto the roofing without cracking or breaking it. Class 4 options include certain metal panels, stone-coated steel, and impact-resistant shingles. In hail-prone San Antonio, a Class 4 roof can reduce storm damage and may qualify for insurance discounts.
How the Test Works
UL 2218 testing drops steel balls of increasing size onto roofing samples. The rating depends on the largest ball the material survives without cracking or rupturing.
- Class 1: 1.25-inch steel ball
- Class 2: 1.5-inch steel ball
- Class 3: 1.75-inch steel ball
- Class 4: 2-inch steel ball (highest rating)
Roof Types That Can Be Class 4
Several roofing materials offer Class 4 rated products. Many metal roofing systems and stone-coated steel products are rated Class 4, and some asphalt shingles are made with rubberized (SBS-modified) asphalt to earn the rating.
The rating belongs to the specific product, so confirm it on the manufacturer's documentation rather than assuming a material qualifies.
What Class 4 Does and Doesn't Mean
Class 4 means the roof resists cracking and puncture from impact. It does not mean the roof cannot be dented or marked. Metal roofs can show cosmetic dents and still meet the standard.
Hail also hits gutters, vents, and skylights, which are not part of the roof rating. A Class 4 roof reduces damage but does not make a home hail-proof.
Comparing Class 4 Options
Class 4 options vary in cost, appearance, and how they show damage. Impact-resistant shingles are often the lowest-cost route to a Class 4 rating and keep a traditional look. Stone-coated steel combines a traditional look with metal durability. Class 4 standing seam and other metal panels offer the longest life.
Each option handles hail differently in real life. Shingles may resist cracking but can still lose granules; metal resists punctures but can show cosmetic dents. Talking through these tradeoffs helps you choose the system that fits your priorities.
- Impact-resistant shingles: lowest-cost Class 4, traditional look
- Stone-coated steel: traditional look, hides dents well
- Class 4 metal panels: longest life, may show cosmetic dents
Is Class 4 Worth It in San Antonio?
For many San Antonio homeowners, yes. The area sees frequent spring hail, and a Class 4 roof can mean fewer claims, fewer deductibles, and potential premium discounts.
We install Class 4 rated roofing systems and can help you compare cost and benefits during a free inspection.
Frequently Asked Questions
Are all metal roofs Class 4?
No. Many are, but the rating depends on the specific panel and installation. Check the product documentation.
Do Class 4 shingles last as long as metal?
Impact-resistant shingles hold up better than standard shingles in hail, but metal roofing generally has a longer overall lifespan.
Will a Class 4 roof lower my insurance?
Many Texas insurers offer discounts for Class 4 roofs. Ask your agent about your specific policy.
Contact Sanchez Metal Roofing
Phone: (210) 708-3308. Email: sanchezmetalroofing123@gmail.com. Address: 520 Fredericksburg Rd, San Antonio, TX 78201. Hours: Monday through Saturday 8:00 AM to 5:00 PM. Free roof inspections across San Antonio. Call (210) 708-3308.