Which statement best describes the purpose of fab cloth in mastic applications?

• A. To aid curing time
• B. To prevent cracking after material dries
• C. To increase chemical resistance
• D. To reduce cost

Answer: (B)

Fabric cloth is used as a reinforcing layer in mastic coatings. When embedded in the wet mastic, it creates a fiber-network that carries tensile stresses as the material dries and shrinks. This reinforcement helps bridge small cracks and distribute movement across the surface, so the coating stays intact rather than cracking open later. That’s why the best description is that the fabric cloth’s purpose is to prevent cracking after the material dries.

It isn’t primarily about speeding up curing, boosting chemical resistance, or reducing cost. Those effects can be secondary or negligible compared to the crack-prevention reinforcement provided by the fabric.