According to NFPA 20, two or more water tanks are required as the primary source for which type of building?

According to NFPA 20, two or more water tanks are required as the primary source for which type of building?

• A. Small one-story building
• B. Very tall building
• C. Underground facility
• D. Residential condo

Answer: (B)

Very tall buildings need a reliable primary water supply that can deliver enough volume and pressure to every floor, especially the upper levels. NFPA 20 addresses this by using two or more water tanks as the primary source. Having multiple tanks provides the necessary head and volume so the fire protection system can meet high flow demands without losing pressure as you go up. Elevated tanks also create gravity-fed pressure, reducing reliance on pumps alone and adding redundancy—if one tank isn’t available, others keep the supply going. In contrast, smaller buildings, underground facilities, or residential condos typically don’t have the same height or demand, so they don’t require multiple primary tanks.

Very tall buildings need a reliable primary water supply that can deliver enough volume and pressure to every floor, especially the upper levels. NFPA 20 addresses this by using two or more water tanks as the primary source. Having multiple tanks provides the necessary head and volume so the fire protection system can meet high flow demands without losing pressure as you go up. Elevated tanks also create gravity-fed pressure, reducing reliance on pumps alone and adding redundancy—if one tank isn’t available, others keep the supply going. In contrast, smaller buildings, underground facilities, or residential condos typically don’t have the same height or demand, so they don’t require multiple primary tanks.