Ontario Building Code Exam: Building Services

Under OBC Division B, Section 6.3.2 (Construction and Installation of Ducts and Plenums), what is the minimum clearance required between a duct and combustible material if the duct carries air at a temperature of not more than 50°C?

• A0 mm
• B25 mm
• C50 mm
• D75 mm

According to OBC Division B, 7.4.8.1, what is the minimum slope required for a horizontal sanitary drainage pipe with a size of 3 inches (75 mm) or less?

• A1 in 50 (2%)
• B1 in 100 (1%)
• C1 in 25 (4%)
• D1 in 200 (0.5%)

Under OBC Division B, Section 7.4.7.2, what is the maximum permitted distance between cleanouts on a horizontal drainage pipe of 3 inches (75 mm) or less?

• A15 metres
• B30 metres
• C7.5 metres
• D25 metres

What is the minimum height above the flood level rim of the fixture that a vent pipe connection must make before running horizontally or joining a vent stack under OBC Division B, 7.5.4.3?

• A150 mm
• B50 mm
• C75 mm
• D300 mm

In a residential occupancy containing a fuel-burning appliance, where must carbon monoxide alarms be installed under OBC Division B, Article 6.9.3.2?

• AInside or within 5 metres of each bedroom
• BDirectly above the fuel-burning appliance
• CIn the main mechanical room only
• DAt the highest point of the ceiling in the living room

Under OBC Division B, Part 7, what is the maximum temperature permitted for hot water delivered to plumbing fixtures in residential occupancies to prevent scalding?

• A49°C
• B60°C
• C55°C
• D43°C

Under OBC Division B, Table 7.3.4.5, what is the maximum horizontal spacing for hangers supporting ABS drainage piping?

• A1.2 metres
• B2.5 metres
• C1.5 metres
• D3.0 metres

What is the minimum trap seal depth required for standard plumbing fixtures under OBC Division B, Section 7.4.5.1?

• A38 mm
• B50 mm
• C25 mm
• D75 mm

Under OBC Division B, what type of backflow prevention device is typically required for a standard exterior hose bibb?

• AHose connection vacuum breaker
• BDouble check valve assembly (DCVA)
• CReduced pressure principle preventer (RP)
• DAtmospheric vacuum breaker (AVB)

What is the fixture unit (FU) rating for a private washbasin (lavatory) with a 1-1/4 inch waste pipe size under OBC Division B, Table 7.4.9.3?

• A1 FU
• B2 FU
• C3 FU
• D4 FU

Under OBC Division B, 7.3.6.1, when testing a rough-in drainage system with water, what is the minimum height of the water column required?

• A3 metres
• B1.5 metres
• C5 metres
• D10 metres

Under OBC Division B, 7.7.1.1, how must non-potable water piping systems be identified inside a building?

• ABy permanent, distinct, and easily recognized markings
• BBy painting the entire pipe solid red
• CBy wrap-around yellow warning tape spaced every 10 metres
• DBy encasing the entire line in a black PVC sleeve

According to OBC Division B, 9.32.3, what is the primary purpose of a Heat Recovery Ventilator (HRV) in a mechanical ventilation system?

• ATo exchange heat between outgoing exhaust air and incoming fresh air
• BTo filter out carbon monoxide from the outdoor air supply
• CTo increase the humidity of the incoming dry outdoor air
• DTo act as the primary heating source for the residential suite

Under OBC Division B, 9.10.13.13.(1), what is the general requirement for a duct that penetrates a fire separation?

• AIt must be equipped with a fire damper
• BIt must be painted with fire-retardant paint
• CIt must be encased in concrete
• DIt must be constructed of combustible materials

What is the minimum horizontal spacing required for hangers supporting horizontal copper water piping of 1 inch or less under OBC Division B, Table 7.3.4.5?

• A2.5 metres
• B1.2 metres
• C1.5 metres
• D3.0 metres

Under OBC Division B, 9.10.10.4, in what type of room must fuel-fired heating appliances in a multi-unit residential building be located?

• AIn a dedicated service room separated by a fire separation
• BIn the public corridor for easy maintenance access
• CDirectly inside the main exit lobby
• DInside any storage room without fire separation

What is the minimum fire-resistance rating required for a service room that contains an incinerator under OBC Division B, 3.6.2.4?

• A2 hours
• B1 hour
• C45 minutes
• D3 hours

Under OBC Division B, Part 6, which of the following is required for a commercial kitchen ventilation hood exhaust duct?

• AIt must lead directly to the outdoors without passing through other suites
• BIt can be constructed of light-duty PVC plastic piping
• CIt may discharge into an attic space if the attic is ventilated
• DIt can connect to a common washroom exhaust duct system

Under the 2024 Ontario Building Code, what is the maximum force required to operate controls, keys, or switches on a barrier-free path of travel?

• A22.2 N
• B50 N
• C10 N
• D15 N

Under OBC Division B, 3.6.2.8, what is the minimum fire-resistance rating required for the separation around an emergency power generator service room?

• A2 hours
• B1 hour
• C45 minutes
• D30 minutes

Under OBC Division B, 9.32.3.4, what is the minimum ventilation capacity required for a master bedroom in a residential dwelling unit?

• A10 L/s
• B5 L/s
• C15 L/s
• D20 L/s

Under OBC Division B, 9.21.1.1, which of the following masonry or concrete structures is regulated as a chimney?

• AA shaft containing one or more flues used to convey product of combustion to the outdoors
• BA masonry intake duct used to supply ventilation air to a crawl space
• CA concrete drainage sump used to collect sanitary waste water
• DAn outdoor brick wall built adjacent to a fireplace for privacy

According to OBC Division B, 7.4.5.3, what is the maximum number of plumbing fixtures that can share a single common trap?

• A3
• B1
• C2
• D4

What is the minimum size of a water service pipe entering a single-family residential dwelling under OBC Division B, 7.6.3.4?

• A3/4 inch
• B1/2 inch
• C1 inch
• D1-1/4 inches

Under OBC Division B, 3.8.3.3, what is the minimum clear width required for a doorway on a barrier-free path of travel when the door is in the open position?

• A860 mm
• B800 mm
• C900 mm
• D750 mm

Under OBC Division B, Section 6.3.2 (Air Duct Systems), which of the following is required for HVAC air filters installed in a building?

• AThey must be easily accessible for inspection and replacement
• BThey must be constructed of combustible cardboard frames only
• CThey must be permanently welded into the ductwork
• DThey must be replaced daily by law

According to OBC Division B, 9.32.3.1, a principal exhaust fan used as part of a residential mechanical ventilation system must be controlled by a switch that is:

• ALocated in an accessible, central area of the dwelling
• BInstalled only inside the attic space
• CHidden behind a wall access panel
• DControlled solely by an automatic wind sensor outdoors

Under OBC Division B, 7.4.2.1, what is the drainage fixture unit (DFU) value assigned to a residential kitchen sink?

• A1.5 FU
• B1 FU
• C3 FU
• D4 FU

Under OBC Division B, Article 6.3.2.3 (Materials in Air Duct Systems), which of the following materials is typically prohibited for use in air ducts carrying supply air?

• ACombustible materials such as wood or cardboard
• BGalvanized sheet steel
• CAluminum sheet metal
• DFibrous glass duct board

According to OBC Division B, 9.31.3.2, every plumbing fixture in a building must be:

• AProvided with a clean water supply and connected to a sanitary drainage system
• BConstructed entirely of solid stainless steel
• CInspected weekly by the local municipal health officer
• DConnected directly to a rainwater collection barrel

For a storage garage in a building, what is the minimum continuous exhaust ventilation rate required per square metre of floor area under OBC Division B, Article 6.3.1.3?

• A3.9 L/s
• B2.0 L/s
• C5.0 L/s
• D1.5 L/s

Under OBC Division B, 3.6.4.3, what is the maximum flame-spread rating permitted for duct materials and coverings used inside a ceiling plenum?

• A25
• B50
• C75
• D150

What is the minimum fire-protection rating required for a fire damper installed in a duct penetrating a 1-hour fire separation under OBC Division B, 3.1.8.4?

• A45 minutes
• B1 hour
• C30 minutes
• D1.5 hours

Under OBC Division B, 7.6.2.9, what is the minimum air gap required for a water supply outlet above the flood level rim of a fixture when the outlet is not affected by adjacent walls?

• ATwo times the effective opening of the water supply pipe, but not less than 25 mm
• BOne times the effective opening, but not less than 13 mm
• CThree times the effective opening, but not less than 50 mm
• D50 mm regardless of pipe diameter

Under OBC Division B, 7.5.6.3, which of the following fixtures is permitted to be wet-vented?

• AA combination of washbasins, bathtubs, and water closets within the same group
• BA commercial kitchen grease interceptor and a high-temperature dishwasher
• CA laundry machine standpipe in a separate fire compartment
• DA dental chair spittoon and chemical waste sink

Under OBC Division B, 3.6.2.1, what is the minimum fire-resistance rating required for a service room containing a boiler with an input capacity exceeding 120 kW?

• A1 hour
• B45 minutes
• C2 hours
• D3 hours

Under OBC Division B, Section 6.3.2 (Air Duct Systems), what is the minimum horizontal clearance required between an outdoor air intake and a commercial kitchen exhaust discharge?

• A3.0 metres
• B1.5 metres
• C6.0 metres
• D4.5 metres

Under OBC Division B, 7.4.4.3.(1), what type of waste must be discharged through a grease interceptor in a food preparation establishment?

• AGrease-laden wastewater from commercial sinks and pre-rinse stations
• BSanitary waste from water closets and urinals
• CClear-water waste from refrigeration condensers
• DRainwater runoff from the restaurant roof

According to OBC Division B, 3.6.2.2, which of the following is true regarding service rooms containing fuel-fired appliances or transformer vaults?

• AThey shall not be located directly under any exit path of travel
• BThey must be located on the roof of the building
• CThey must have at least two exit doors leading to the exterior
• DThey are permitted to share a common plenum with public corridors

Under OBC Division B, 7.4.6.1, when is a sump pump or sewage ejector required for a building's plumbing system?

• AWhen gravity drainage to the public sewer is not possible
• BFor all multi-family buildings regardless of elevation
• CWhen the building has a water meter installed
• DOnly when the sanitary line is constructed of copper

What is the minimum clearance required around a cleanout on a drainage line to allow for cleaning equipment under OBC Division B, 7.4.7.1?

• A300 mm for pipes 4 inches or less, and 450 mm for larger pipes
• B150 mm for all pipe sizes
• C600 mm regardless of pipe diameter
• DNo minimum clearance is specified

Under OBC Division B, 3.6.3.3, what is the minimum fire-resistance rating required for a linen or refuse chute enclosure wall?

• A1 hour
• B45 minutes
• C2 hours
• D30 minutes

Under OBC Division B, Section 3.1.8. (Protection of Openings in Fire Separations), what is the maximum area of a opening in a fire separation that may be left unprotected by a fire damper for a duct penetration?

• A0.08 m²
• B0.02 m²
• C0.15 m²
• D0.50 m²

According to OBC Division B, 9.32.3.1, a principal ventilation system fan must be designed for:

• AContinuous operation to maintain indoor air quality
• BIntermittent operation controlled only by a bathroom light switch
• COperating only when the outdoor temperature exceeds 30°C
• DOperating solely under manual override by the building inspector

Under OBC Division B, 7.4.10.4, roof drains must be designed with what type of device to prevent debris from clogging the leader?

• AA strainer that extends above the roof membrane
• BA flat steel cover plates
• CAn automatic mechanical grinder
• DA sand filter bed

What is the minimum diameter required for a sanitary building sewer line serving a single-family dwelling under OBC Division B, Section 7.4.9.4?

• A4 inches (100 mm)
• B3 inches (75 mm)
• C2 inches (50 mm)
• D6 inches (150 mm)

Under OBC Division B, Section 6.3.2 (Construction and Installation of Ducts and Plenums), what is the minimum clearance to combustible material required for a supply duct carrying air at temperatures between 50°C and 120°C?

• A25 mm
• B0 mm
• C50 mm
• D75 mm