Large Buildings and Fire Protection

Firestopping is installed mainly in large building but may be found in small residential multi-family units etc. Firestopping is installed in strategic locations to resist the passage of fire from one area to another.  One use of firestopping is to maintain the integrity of fires separations such as penetrations by pipes, wires or other building services.  The second purpose is to limit the size of concealed spaces as found in stud walls, attics, crawl spaces, and spaces in between the superstructure and exterior building envelope.


Firestop systems are rated based on tests in accordance with CAN4-S115-M, “Standard Method of Fire Tests of Firestop Systems. Four ratings ( F, FT, FH and FTH) are assigned based on test results.


Firewalls are a special type of masonry or concrete fire separation that subdivide a building into two or more entities with a fire-resistance rating from between 2 to 4 hours. Firewalls are usually used by designers to limit size of individual areas to allow for cheaper construction costs by eliminating need for expensive fire-protection equipment such as sprinklers etc. This procedure does not apply to fire alarm or detection system however as this is based on entire buildings “gross area.”


Flame Spread and Interior Finishes is the measurement of the surface characteristics of materials used in finishing buildings. Buildings are broken down into three categories which are combustible construction, non-combustible construction and high rise buildings. This is broken down into a further sub-category of whether building is sprinklered or not. The Ontario Building Code provides tables which provides the rules that govern finishes on walls, ceilings, surface – rating applies to surface only and cut test – which applies to any surface that can be exposed by cutting.


The importance of fire protection has been proven over and over again when lives have been lost in large buildings whose fire protection equipment has been either compromised or disabled for various reasons. One large fire in a high rise, which started in café on first floor, which contributed to lost lives, was blamed on missing fire-stopping. Such a small failure can have disastrous consequences.


This is our second article on large buildings based on requirements of the Ontario Building Code.  We will be endeavouring to provide basic information which we use on inspecting large buildings. Municipal inspectors are not permitted to inspect buildings that they do not hold qualifications for but there is no such restriction in place for commercial building inspectors.  Caveat Emptor – Buyer Beware