1.4 Testing, Inspection, Maintenance & Repairs (SPS 382.21, 382.22)
Key Takeaways
Drain and vent systems are tested with water (no section under a 10-foot head, held 15 minutes) or air (5 psi or 10 inches of mercury, held 15 minutes without adding air).
Sanitary building sewers are tested with a 10-foot water head for 15 minutes or 3 psi of air for 15 minutes; storm building sewers need no field test.
Water distribution piping, water services and private water mains are proved watertight under water pressure not less than the working pressure, using potable water.
If the inspector does not inspect by the end of the next business day after notice, the plumber may proceed with testing and installation.
A required final test uses smoke or air at a pressure equal to 1 inch of water column; the air version must hold for 5 minutes.
When testing is required (SPS 382.21 (1))
All new plumbing, and every part of an existing system that is altered, extended or repaired, must be tested and inspected before being put into operation. Exceptions:
- No test is needed if the work adds, replaces, alters or relocates no water distribution, drain or vent piping. A direct fixture swap is an example.
- Storm building sewers and storm private interceptor main sewers need no field test, but their joints must meet SPS 384.40 (1) (a).
Inspection procedure (SPS 382.21 (1) (b))
| Step | Rule |
|---|---|
| Notice | The plumber responsible notifies the inspector in person, by phone or in writing when work is ready |
| If the inspector doesn't come | If the inspection isn't made by the end of the normal business day following the day of notification (excluding weekends and legal holidays), the plumber may proceed with testing and installation |
| Self-test option | Testing may be done without the inspector if the master plumber gets permission to submit a written test report in a format the inspector accepts |
| Preparation | The plumber provides access to all parts, the test apparatus and assistance |
| Rough-in inspection | Made when the system is roughed in and before fixtures are set; no work closed in until approved |
| Final inspection | Made on completion, before final approval |
| Reinspection | Corrections are made and the work resubmitted |
One- and 2-family dwellings are inspected under SPS 320.08 to 320.11. The initial test of a backflow assembly follows SPS 382.22 (8) (section 6.3). The plumber furnishes all equipment, material and labor for tests, and covered work must be exposed for testing.
Test methods (SPS 382.21 (2))
| System | Water test | Air test |
|---|---|---|
| Drain and vent systems (including conductors), and building drains brought to grade | Fill to overflow, or test in sections; no section under a 10-foot head, and the upper 10 ft of each preceding section retested; hold 15 minutes before inspection | 5 psi gauge pressure, or enough to balance 10 inches of mercury, held 15 minutes without adding air |
| Sanitary building sewer and sanitary private interceptor main sewer (before or after covering; manholes excluded) | Plug at the public sewer, fill to at least a 10-foot head, no drop for 15 minutes | 3 psi, held 15 minutes without adding air |
| Private water mains and water services | Inspect before covering; prove watertight under water pressure not less than the working pressure, potable water | - |
| Water distribution system | Prove watertight under water pressure not less than the working pressure, potable water | - |
Note
NFPA 24 may impose more stringent tests on combination water services and private mains that also feed fire protection (section 5.5).
Pressure check. A 10-foot water column exerts about 10 x 0.433 = 4.3 psi at its base, which is why the air test for drain and vent piping is set at 5 psi. When testing a 3-story stack in sections, each lower section must also retest the bottom 10 feet of the section above.
Final test (SPS 382.21 (2) (h))
Where the local inspector or municipality requires it, after fixtures are set and traps filled:
- Smoke test: pungent, thick smoke from smoke machines; when it appears at roof openings, close them and hold 1 inch of water column during the inspection.
- Air test: add air until the system holds 1 inch of water column, constant for at least 5 minutes without adding air.
The plumbing code does not include a peppermint test.
Maintenance and repairs (SPS 382.22)
- The owner maintains plumbing in a safe, sanitary condition, with required devices in working order.
- Existing systems may stay if maintained per their original design and installed under the code in effect then, or if they meet the current code. A system that creates a hazard must be repaired or replaced, or brought up to the current code on the authority's schedule. DSPS considers a cross connection a health hazard.
- An existing sewer or water service may serve a new building only after examination and testing show it conforms.
- Replacement fixtures, appliances or pipe must meet the current code. Where old drain or vent piping doesn't comply, DSPS may require deep-seal traps on the new fixtures.
- Reused materials need approval from DSPS or the local inspector plus the owner's written consent. Water supply piping may be reused only for an equal or higher hazard use.
- Repairs must meet the code. Repair clamps or bands are allowed only in emergencies.
- Demolition: seal and plug all sanitary, storm and water connections safely.
- Dead ends created by removing drain piping are sealed per SPS 384.40.
Worked scenario
A plumber roughs in a 2-story addition on Monday morning and calls the inspector. If no inspector arrives by the end of Tuesday (the next business day), the plumber may test and continue. Before Monday's call, the plumber should already have:
- capped and filled the DWV to the roof with water (10-foot sections at minimum), or charged it to 5 psi of air
- pressurized the new water piping with potable water to at least working pressure
- kept the new building sewer uncovered or ready for a 10-foot head or 3 psi air test
What air test does SPS 382.21 (2) (g) prescribe for drain and vent piping?
3 psi held for 15 minutes, the same as the building sewer air test
5 psi or 10 inches of mercury, held 15 minutes without adding air
10 psi held for 5 minutes, with the gauge read at the base of the stack
1 inch of water column held for 5 minutes after the fixtures are set
How must a new water distribution system be tested under SPS 382.21 (2) (f)?
With air at 100 psi or working pressure, whichever is greater, for 15 minutes
With water at 150 psi for 2 hours, regardless of the working pressure
With potable water at no less than the working pressure
No test is required when the piping is PEX with listed crimp fittings
A plumber notifies the inspector on Thursday that rough-in is ready. Friday is a normal business day. Under SPS 382.21 (1) (b) 1. b., when may the plumber proceed without the inspector?
After 5 business days have passed without an inspection
Never; the plumber must wait for the inspector's written permission
After the end of the following Monday, the second business day
After the end of Friday, if no inspection was made
Sections you finish are checked off in the contents.