Plumbing Installation Inspection

Per NPC Section 2.2, water supply piping must be sized to deliver adequate flow and pressure to all fixtures. Pipe materials must comply with CSA B137 (thermoplastic) or be copper meeting ASTM B88. PEX piping must meet CSA B137.5. All piping must be pressure tested at 690 kPa (100 psi) for a minimum of 15 minutes with no loss per NPC 2.2.10.17. Piping must be supported at intervals per NPC Table 2.2.10.11.

1. Verify pipe material is approved per NPC — copper, PEX (CSA B137.5), or CPVC with CSA certification

2. Confirm pipe sizing matches the NPC fixture unit calculation for the connected fixtures

3. Check that water supply system has been pressure tested at 690 kPa for minimum 15 minutes per NPC 2.2.10.17

4. Verify pipe supports at required intervals per NPC Table 2.2.10.11 — copper at 1.8 m, PEX at 800 mm

5. Confirm hot and cold piping is separated by minimum 150 mm or hot pipe is insulated where parallel

- Supply piping undersized causing low pressure at remote fixtures

- Pressure test not performed or documented before close-in

- Pipe supports missing or spaced too far apart causing sagging

- PEX piping exposed to UV light during construction causing degradation

Per NPC Section 2.3 and 2.4, drain and vent piping must be properly sized based on fixture units and must maintain required slopes — minimum 1:50 (2%) for pipes 75 mm and smaller, 1:100 (1%) for pipes 100 mm and larger. Vent piping must extend through the roof to open air per NPC 2.4.4. ABS (CSA B181.1) and PVC (CSA B181.2) are common DWV materials in Canada. All DWV systems must pass a water or air test per NPC 2.3.6.

1. Verify drain pipe sizing matches NPC fixture unit tables for the connected fixtures

2. Confirm drain slopes meet NPC minimums — 2% for 75 mm and smaller, 1% for 100 mm and larger

3. Check that vent piping extends through the roof and terminates per NPC 2.4.4 — minimum 150 mm above roof

4. Verify DWV system has been tested per NPC 2.3.6 with results documented

5. Confirm cleanouts are provided at required locations — base of each stack, changes in direction, and per NPC 2.3.5

- Drain pipes with insufficient slope causing slow drainage and blockages

- Vent piping terminated in attic instead of extending through the roof

- Missing cleanouts at required locations making future maintenance difficult

- Incorrect fittings used in DWV system — sanitary fittings required on drain lines

Per CSA B64 and NPC 2.2.4, cross-connections must be protected by appropriate backflow prevention devices. The level of protection depends on the degree of hazard — severe hazard requires a reduced pressure principle (RP) device, moderate hazard requires a double check valve assembly (DCVA). All faucets and fixtures must maintain the required air gap per NPC or have an approved backflow preventer. Testable devices must be accessible for annual testing.

1. Verify backflow prevention devices are installed at all cross-connections per NPC 2.2.4 and CSA B64

2. Confirm device type matches the hazard level — RP for severe, DCVA for moderate hazard

3. Check that hose bibs have vacuum breakers installed per NPC requirements

4. Verify all testable backflow prevention devices are accessible for annual testing and maintenance

5. Confirm air gaps at fixtures meet NPC requirements — minimum 25 mm or two times the pipe diameter

- Missing backflow prevention on irrigation system connections

- Hose bibs without vacuum breakers allowing potential contamination

- Testable devices installed in inaccessible locations

- Wrong device type for the hazard classification

Per NPC and CSA B45, all plumbing fixtures must be CSA-certified and installed per manufacturer instructions. Fixtures must be secured to the structure and sealed to the wall or floor. Water closets must be set on a properly installed closet flange. Faucets and fittings must comply with CSA B125 and meet water efficiency requirements — maximum 8.3 L/min for lavatory faucets, 9.5 L/min for kitchen, and 6 L/flush for water closets per NPC.

1. Verify all fixtures bear CSA certification marking and are installed per manufacturer instructions

2. Confirm water closets are secured to a properly installed closet flange with a wax or foam seal

3. Check that fixture supply stops (shut-off valves) are installed and accessible for each fixture

4. Verify fixture drain connections are properly sealed — no leaks when fixtures are filled and drained

5. Confirm fixture flow rates meet water efficiency requirements per NPC and provincial regulations

- Water closet not properly secured to the closet flange causing rocking and wax seal failure

- Missing shut-off valves at individual fixtures

- Fixture drain connections leaking at trap or tailpiece joints

- Fixtures not CSA-certified or fittings exceeding maximum flow rates

Per NPC and CSA B149.1 (gas) or CEC (electric), water heaters must be CSA-certified and installed per manufacturer instructions. Gas water heaters must be vented per CSA B149.1 and have adequate combustion air. A temperature and pressure relief (TPR) valve must be installed per CSA Z21.22 and the discharge pipe must terminate within 150 mm of the floor or to an approved drain. Maximum water temperature at fixtures must not exceed 49 degrees C per NPC using thermostatic mixing valves.

1. Verify water heater is CSA-certified and installed per manufacturer instructions with proper clearances

2. Confirm TPR valve is installed and discharge pipe terminates within 150 mm of the floor or to approved drain

3. Check gas venting per CSA B149.1 — proper connector size, slope, and chimney type

4. Verify thermostatic mixing valve is installed to limit fixture delivery temperature to maximum 49 degrees C per NPC

5. Confirm seismic strapping is installed where required by local authority

- TPR valve discharge pipe missing, capped, or routed upward trapping condensation

- Gas water heater venting inadequate causing combustion gas spillage

- Missing thermostatic mixing valve allowing scalding water at fixtures

- Water heater installed without required clearances to combustibles

Per NPC and NBC 9.14, storm water must be managed separately from sanitary drainage. Foundation drainage (weeping tile) must connect to a sump pit with a pump or drain to daylight per NBC 9.14.2. Sump pits must have a sealed cover per NBC 9.14.5. Roof drainage and downspouts must discharge to grade away from the building or to the storm sewer where connected. Floor drains in basements must connect to sanitary drainage with a trap primer or barrier trap.

1. Verify weeping tile connects to a sump pit with a functioning pump or drains to a positive outlet

2. Confirm sump pit has a sealed cover to prevent soil gas entry per NBC 9.14.5

3. Check that downspouts discharge away from the building — minimum 1.5 m from the foundation

4. Verify basement floor drains are connected to sanitary drainage with proper trap per NPC

5. Confirm storm and sanitary drainage systems are separate with no cross-connections

- Sump pump not connected to a discharge point away from the building causing recirculation

- Sump pit cover missing or unsealed allowing soil gas and radon entry

- Downspouts discharging directly at the foundation causing water intrusion

- Storm and sanitary drainage inadvertently connected

Per NPC and NBC 9.25, water supply piping in unheated spaces must be protected against freezing. Piping in exterior walls, attics, crawl spaces, and garages must be insulated or heat-traced. Hot water piping must be insulated per NBC Part 6 and NECB for energy efficiency. All piping penetrating the building envelope must be sealed to maintain air barrier continuity per NBC 9.25.

1. Verify all water supply piping in unheated spaces is insulated or heat-traced to prevent freezing

2. Confirm piping in exterior walls is on the warm side of the insulation per NBC 9.25

3. Check that hot water piping is insulated per NECB requirements for energy efficiency

4. Verify all piping penetrations through the building envelope are sealed for air barrier continuity

5. Confirm heat trace systems, if installed, are CSA-certified and properly connected to power

- Supply piping in exterior walls on the cold side of insulation freezing in winter

- Hot water piping not insulated resulting in energy loss and long wait times

- Piping penetrations through the envelope not sealed creating air leakage paths

- Heat trace not installed on vulnerable piping in garages or crawl spaces