When sourcing building materials, you must prioritize load-bearing capacity, tensile strength, and durability. For steel products, verify the grade (e.g., ASTM A36 or S235JR) and ensure they have undergone anti-corrosion treatments like hot-dip galvanization. For cement and concrete, check the compressive strength ratings (e.g., C30, C40). Always request Material Test Reports (MTRs) to confirm that the chemical composition and physical properties align with your project's engineering requirements.