What term is used when smoke rises vertically then spreads sideways?

• A. Mushrooming
• B. Puffing
• C. Jetting
• D. Seeping

Answer: (A)

Smoke behavior shows how heat and air interact. Hot gases rise quickly, forming a vertical plume. As the plume ascends and cools, it loses momentum and spreads outward at the top, creating a mushroom-like cap. That pattern is described as mushrooming. It helps indicate how the fire’s heat is moving and what ventilation might be doing. Other patterns are different: a puffing effect is intermittent bursts, jetting is a narrow, focused stream, and seeping is slow leakage through cracks; none of these describe the distinct vertical rise followed by sideways spreading.