High-quality non-asbestos roofing sheets are typically composed of PVA fibers, high-grade Portland cement, and reinforced cellulose fibers. When sourcing, you must ensure the product complies with ISO 9933 or ASTM C1185 standards. Key technical indicators include a density of at least 1.4g/cm³ and a bending strength (modulus of rupture) exceeding 16 MPa. For B2B buyers, it is critical to verify that the asbestos content is 0%, as even trace amounts can lead to severe legal and health liabilities in many jurisdictions.