GLOSSARY

Fire Wall (Firewall)

A fire wall is a fire-resistance-rated wall, continuous from the foundation to or through the roof, with enough structural stability that construction on either side can collapse in a fire without bringing the wall down.

A FIRE WALL MAKES ONE STRUCTURE TWO BUILDINGS FOR CODE PURPOSESBUILDING ABUILDING BPARAPET ABOVE ROOFFOUNDATION TO ROOF, RATED 2 TO 4 HOURSMAY COLLAPSEMAY COLLAPSETHE WALL MUST STAY STANDING
A fire wall is continuous from the foundation through the roof and structurally independent, so each side is treated as a separate building for allowable area and height. Fire barriers and fire partitions are lighter separations within one building. Illustrative.

Under the International Building Code (Section 706), a fire wall divides a structure into separate buildings for code purposes. Each side is then judged on its own for allowable height, area and construction type. Required ratings depend on occupancy and range from 2 to 4 hours; parking garages in Group S-2 generally require 2 hours. Fire walls are distinct from fire barriers and fire partitions, which separate spaces within one building, and from a smoke barrier, which limits smoke movement.

Fire walls and parking

  • Separating a garage from another building. A fire wall lets an attached garage and an adjacent building be treated as two buildings, each within its own area and height limits.
  • Mixed-use podiums. Where a garage sits below other occupancies, the separation is usually a rated horizontal assembly under the IBC’s podium provisions rather than a fire wall.
  • Openings. Openings through a fire wall are limited in size and must be protected with rated doors or shutters, which can complicate drive aisles between garage sections.
  • Continuity. The wall usually extends above the roof as a parapet and must be continuous through every floor, so it constrains the structural grid.

In PARCS and parking technology

  • In parking technology, a firewall is a network security device or software that controls traffic between a facility’s PARCS, payment equipment and outside networks. Payment card rules require one between card-handling systems and other networks. See PARCS.

The Parkonomics view

Fire walls are a planning decision, not a detail. Deciding early whether a garage and its neighbor are one building or two changes construction type, sprinklers, egress and cost. Settle it with the code consultant before the structural grid is drawn.

Related terms: Smoke Barrier, 1-Hour Fire Resistance, Building Code, International Building Code, Enclosed Parking Garage