Fire Prevention & Protection, Firefighter Training, Truck Company

Reading A Building – Commercials

By John W. Mittendorf

Commercial buildings come in a wide variety of sizes, heights, floor plans, content, etc. This list of variances is the reason an initial size-up should include the approximate size of a commercial building. There is a significant difference between a single-story commercial building that is 30 x 30 and a three-story, 150 x 200 commercial building. Other common considerations follow.

The approximate age of the building can be an excellent indicator of the type of construction (conventional, lightweight, real masonry – not brick veneer on a metal frame, etc.), and provide some insight into the approximate interior of the building. For example, older commercials may have been renovated numerous times to accommodate various owners, thereby making a size-up of the floor plan difficult. Numerous renovations also increase the chance of substandard construction. Conversely, newer commercial buildings often have a “standard floor plan” that is easily recognized from the exterior of the building.

This one is simple. Does the building have a common attic, an attic that has visible division walls, and are attic vents also visible? Attic vents can be an indicator of extension of smoke/fire into an attic.

This one is not so simple, as commercial buildings come in an unlimited variety of sizes and heights. Several items to consider are:

  • Is the building a part of other buildings, or is it a standalone structure?
  • Is the building a single-story or multiple-story structure? If it is a multiple-story structure, remember that the higher the fire, the longer it will take your resources to reach the fire.
  • The time of day often indicates if the building is vacant or occupied. Also consider holidays.
  • The larger the building, the more resources are required to find and fix a problem.

The name on the exterior of a commercial building is an excellent indicator of the interior of a building. Also consider if the building is all commercial or commercial on the first or lower floors residential on the upper floor or floors. This will dramatically change your search and rescue considerations in concert with the time of day.

Roof Location
If a commercial building has parapet walls, a fascia/mansard, and/or if the roof is not visible from the ground, you should ask the question, “Where is the roof line below the parapet wall, mansard, etc.?” If the roof line is five feet or more below a parapet wall and you are going to the roof, how many ladders will it take to safely allow you to go from the ground to the roof? The answer is two: one from the ground to the top of the parapet wall, and one from the top of the parapet wall to the roof. If you were on a roof and the roof suddenly started to collapse, how far can you jump to reach the top of that parapet wall with full PPE on (if a ladder was not there)? You might be able to jump five feet – maybe. So preplan your roof operation from the ground before you commit yourself. From the ground, consider any visible indicators including:

  • The distance between top floor windows and the top of parapets, etc.
  • For fascias and mansards, scuppers will indicate the roof line.
  • The presence of equipment (HVAC units, air conditioning units), turbine ventilators, etc.

John W. Mittendorf joined the Los Angeles City (CA) Fire Department (LAFD) in 1963, rising to the rank of captain II, task force commander. In 1981, he was promoted to battalion chief and in the year following became the commander of the In-Service Training Section. In 1993, he retired from LAFD after 30 years of service. Mittendorf has been a member of the National Fire Protection Research Foundation on Engineered Lightweight Construction Technical Advisory Committee. He has provided training programs for the National Fire Academy in Emmitsburg, Maryland; the University of California at Los Angeles; and the British Fire Academy at Morton-in-Marsh, England. He is a member of the editorial advisory board of Fire Engineering and author of the books Truck Company Operations (Fire Engineering, 1998) and Facing the Promotional Interview (Fire Engineering, 2003).