The two general types of APP polymer bitumen sheets are which of the following?

• A. Asphalt-coated, polyester-reinforced
• B. Fiberglass-reinforced, asphalt-coated
• C. Asphalt-coated only
• D. Polyester-reinforced only

Answer: (A)

APP polymer bitumen sheets come in two broad forms: asphalt-coated and polyester-reinforced. The asphalt-coated type has its surface saturated with asphalt, giving a traditional, pliable membrane that works well with heat-welding and asphalt-based adhesives. The polyester-reinforced type uses a polyester fabric within the membrane to provide higher tensile strength and better dimensional stability, improving tear resistance and long-term durability. While fiberglass reinforcement is also common in some membranes, it represents a reinforcement option rather than one of the two main forms described here.