Distinguish damp-proofing from waterproofing in below-grade masonry foundations.

• A. Damp-proofing reduces moisture penetration passively; waterproofing provides a full barrier against water under hydrostatic pressure.
• B. Damp-proofing creates a full barrier to water; waterproofing only slows moisture.
• C. Damp-proofing is decorative; waterproofing is structural.
• D. Damp-proofing uses tar; waterproofing uses paint.

Answer: (A)

Damp-proofing and waterproofing handle moisture in different ways. Damp-proofing creates a treatment that slows or limits moisture movement through below-grade masonry by resisting diffusion and capillary action, but it does not stop water when there's actual hydrostatic pressure pushing against the wall. Waterproofing, by contrast, is intended to be an impermeable barrier that can withstand groundwater pressure, providing a continuous defense against water intrusion under hydrostatic pressure. In practical terms, damp-proofing is used where there’s little to no water pressure and good drainage, while waterproofing is chosen where soil is saturated or water tables are high and a true water barrier is needed. Materials for damp-proofing are typically lighter coatings or bituminous/cementitious barriers, whereas waterproofing relies on membranes or more robust liquid-applied coatings designed to resist hydrostatic forces.