Passive Fire Protection

When do you use intumescent coating instead of spray-applied cementitious fireproofing on structural steel?

Intumescent is specified where the steel stays visible — lobbies, atriums, exposed beams in restaurants — because it cures to a thin paint-like finish and only swells into an insulating char during a fire. Cementitious SFRM is the cheaper workhorse for concealed steel above ceilings and behind walls; it goes on thick and rough but is fully UL-listed for 1–4 hour ratings at a fraction of the per-square-foot cost.

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