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Plumbing Code Forum Questions and Answers


3/8 inch Pipe
Abrasion protection - ABS pipe
Backfill material
Backflow devices
Cutting and Notching
Espresso and Soda Machine Drains
Fernco Couplings
Fire-Sprinkler Head
Installation of Storm and Sanitary Pipe
Minor Labels
Permits (Residential)
Pipe in ground installation
Pipe Strapping
Relief Drain Pipe Requirements
Septic Systems
Shower Valves
Trap Arm Offset
Vent Piping
Vented Floor Sinks
Water heaters - elevation requirements
Water heaters - minor label questions
Water Heater Relief Valve Discharge Piping
Water heaters - Size
Water Pipe Replacement - Lost Grounding
Water Service
Water Testing
Where a Plumbing Inspection Begins - Water Pump
Where a Plumbing Inspection Begins - Well

Whirlpool and Standard Waste Lines
Y Fittings

3/8-inch Pipe

Q: Is 3/8-inch water piping permitted by code?

A. Half- inch pipe is the minimum that can be used for water distribution as per chapter 6. 3/8 inch tubing can be used as a properly sized fixture supply. 3/8 inch tubing may also be used in an Appendix A system. (Tri-County Plumbing Code Forum, October 17, 2002)


Abrasion protection-ABS pipe

Q. What is the requirement for abrasion protection of ABS pipe passing through metal stud- walls?

A. Refer to Section 310 and the manufacturer's installation standards. Installation Standard 5, Section 314.1, states: "Hangers and straps shall not compress, distort, cut or abrade the piping and shall allow free movement of pipe. Pipe exposed to damage by sharp surfaces shall be protected."

Backfill Material

1. Q. What kind of material can you use for backfill when bedding a water service?

A. Clean fill dirt, sand or ¾ minus crushed rock. (Tri-County Plumbing Code Forum, January 24, 2002)

BackFlow Devices

1. Q. What type of backflow device is needed on a hot water or steam boiler feed line (geared for dedicated heating)?

A. A Reduced Pressure Double Check Valve (RP device) assembly is the only choice.
(Tri-County Plumbing Code Forum, January 24, 2002)

2. Q. What type of device is needed on a steam boiler with a non-pressurized, open to the atmosphere, boiler feed pump tank, with a float operated valve to let the water into the tank?

A. An air gap meets the requirement for systems that are open to the atmosphere.
(Tri-County Plumbing Code Forum, January 24, 2002)

3. Q. What type of device is needed for a closed, hot water heating system with all potable materials?

A. When the system is closed, that is, isolated from the potable system but still connected through a water supply line, an RP device is required.
(Tri-County Plumbing Code Forum, January 24, 2002)

4. Q. What device would be required for systems using non-listed material.

A. RP device. (Tri-County Plumbing Code Forum, January 24, 2002)

5. Q. Is there a difference in devices between a one/two family dwelling and a commercial building

A. No. (Tri-County Plumbing Code Forum, January 24, 2002)

6. Q. If a residential fire-sprinkler system is not multipurpose, are there any requirements beyond plumbing-license requirements for the installer of the back-flow-prevention device?

A. No. However, CCB registration is required for the contractor doing the work.

7. Q: Does the connection of the irrigation system to the domestic water service and the piping from there to the backflow protection device need to be left open for inspection?

Yes. (Tri-County Plumbing Code Forum, October 17, 2002)


1. Q. If the branch line shown in the illustration were over a garage, would it be considered to be on the second floor, therefore not requiring a cleanout? Code Section 4PC 707.4, Exception #3, One- and Two-Family Dwelling Code, 3507.4, Exception #3.

A. If it is the building drain or the building drain's horizontal branch, it does require a cleanout. Whether the area over the garage constitutes a first or second floor is a building code question. However, a cleanout is good plumbing practice. See illustration.

Background: Several questions have arisen concerning the location of clean outs and the type of 90-degree elbow required at the apex of the loop vent. This is in reference to Section 909.0 of the PSC and Section 3608.1 of the DSC. (Tri-County Plumbing Code Forum, October 17, 2002)

Q: Does the end of the line clean-out that's shown on the drawing (to be handed out at meeting) have to be located in that position or can it be located in the vertical drain line within the cabinet?

A. Either position is acceptable per code. (Tri-County Plumbing Code Forum, April 25, 2002)

Q. Can the vertical foot vent clean-out be located on accessible portion of the vertical piping?

A. Yes. (Tri-County Plumbing Code Forum, April 25, 2002)

Cutting and Notching

1. Q. In my jurisdiction, the plumbing inspectors have been calling the cutting and notching code section 3113.11 of the One & Two Family Dwelling Code. The contractors and subcontractors have told us we are the only jurisdiction in the state making these calls. How is over cutting and notching justified without corrections? Please advise us so that we can be consistent with other Tri-County jurisdictions.

A. Since the cutting and notching provision is in the plumbing code, such violations may and should be addressed by the plumbing inspector. And since this provision is also in the building code it is also the responsibility of the carpenter or framer. The code panel recommends that the plumbing and building contractor communicate about any boring or notching problems that must be repaired before inspections, and if there are problems, the plumbing/building inspector should meet with the plumbing and building contractor on-site to discuss the situation. (Tri-County Code Forum, October 25, 2001)

Espresso and Soda Machine Drains

1. Q. Relying on code cite 1006.00 of the Oregon Plumbing Code, one Tri-County jurisdiction holds that when a floor drain or a floor sink receives the discharge from an espresso or soda machine, the drain must be vented. This jurisdiction seems to be the only jurisdiction in the Tri-County area that applies the code this way. What does the panel think?

A. No. OSPSC Section 1006.0 exception requires floor sinks, hub drains and similar indirect waste receptors that receive the discharge waste from fixtures only shall be individually vented and the trap primer is not required. Espresso and soda machines are not fixtures, they are pieces of equipment. Therefore the indirect waste receptor serving those devices shall be trapped and primed but not vented as per Section 1006.0, Table 10-1.1 and Section 1007.0, O.S.P.S.C. The term "fixture" as used in Section 1006.0 Exception, means a sink type fixture only which is required to have an indirect drain. Examples would be a food prep sink, vegetable or fruit prep sink or a meat prep sink. As long as the floor sink/drain trap is in compliance with table 10.1.1 of the Oregon Plumbing Code, an individual vent is not required. (Tri-County Code Forum, October 25, 2001)

Fernco Couplings

Q: Can a Fernco coupling be used underground to join like materials? Specifically same size ABS to same size ABS. One jurisdiction said it could only be used as a transition fitting.

A. Yes. A Fernco may be used in this application. (Tri-County Plumbing Code Forum, July 25, 2002

Fire-Sprinkler Head

Q. How do you measure the distance a fire-sprinkler head will cover? Is it measured from the farthest corner (diagonal) of the room or from the farthest wall of the room?

A. Sprinkler manufacturers provide coverage specifications and dimensions for their products. Follow the manufacturer's instructions. (See NFPA 13D, 1999 Edition.)

Fire Sprinkler Systems

Q: With respect to NFPA 13D fire sprinkler systems why does a multi-purpose system inspected by plumbing inspectors only have to have pipe listed for potable water and not listed for fire lines like the 1&2 family plans examiners and structural inspectors require?? NFPA 13D 1-5.2 states "only listed and approved devices and approved material shall be used in sprinkler systems" with some exceptions but not for the pipe. Also 3-3.2 requires listing of pipe for sprinkler systems. See appendix A-3-3.2 which further explains the listing requirement.

A: Plumbing product approval standards exceed the "listing" requirements addressed in NFPA 13D. (See section A-1-3 of the standard) This section states that "listed" means different things based upon the authority having jurisdiction. In this case (multi-purpose) residential fire sprinklers are "plumbing" and require plumbing product approval by Oregon statute and Federal Law (EPA Clean Drinking Water Act). ORS 447.026 specifically requires approval of the State Plumbing Board for potable water piping. Also, State Health Division statutes ORS 448.330, requires product approval for any water piping which is used to carry private or public potable water in our state. The Health Division by rule has recognized the plumbing product approval by our division as meeting that statute and federal standards. The reason for this is simply that fire listed sprinkler piping standards are not acceptable for potable water piping. Many of the fire listed materials or products are not acceptable for drinking water. Piping materials such as aluminum, thin walled black steel or cast iron are not safe for drinking water use or do not meet the strength and durability standards for plumbing pipes within a building.

When a stand alone fire sprinkler system is installed in a commercial or residential structure it is not plumbing and the lesser standards for piping material may be used. We do not have authority to regulate this piping system under the plumbing statutes. Therefor, the materials used may be as approved by the structural program which regulates the installation. The structural program does not have statute authority to require product approval. I am not the expert, but I don't believe the structural code addresses product approval except by reference to meeting other standards such as the NFPA standards. So the term "listed" as used in that standard in reference to the State Structural Code is undefined, because there is no authority having jurisdiction. (Tri-County Plumbing Code Forum, October 17, 2002)


1. Q. Sometimes there are multiple permits for one job. When one permit is phoned in for an inspection, the inspectors take out all the permits and perform inspections on permits for which no inspection was requested in addition to the one which was requested. Staff is concerned that the other permits will not be inspected and that the contractor will cover the work. Is this appropriate? Should not all permits be phoned in separately for inspection?

A. No, it is not appropriate for inspectors to perform inspections on permits for which no inspection was requested. Yes, all permits should be phoned in separately for inspection; it is not up to the inspector to determine when the work is done; this is the responsibility of the contractor. When a contractor covers work that should be inspected it is a compliance issue that should be dealt with separately. (June 19 Tri-County Electrical Code Forum)

Installation of Storm and Sanitary Pipe

Q: A contractor has been contracted to build a two-story structure. The structure will be built on two different permits. The first permit is slab-on-grade parking lot. The second, the second floor of the structure. Can an unlicensed person install storm and sanitary pipe under this structure? The pipe is approved inside/under a building. Is this the intent of the code?

A: No. A licensed installer is required to perform the work within the structure. There is no exemption in the statute. (Tri-County Plumbing Code Forum, July 25, 2002)

Loop Vents

Q. Can the 90-degree elbow between the 45-degree elbows on the loop vent be a "Short pattern vent 90 degree or a "Medium sweep drainage 90 degree or a "Long sweep radius 90 degrees?

A. A medium-sweep or a long-sweep elbow may be used along with two 45 degree elbows to meet the code requirements for the top of the loop vent. (Tri-County Plumbing Code Forum, April 25, 2002)

Minor Labels

1. Q. OAR 918-780-0140 (1), (2) describes "plumbing systems" and "plumbing fixtures." Does the scope of work under a plumbing minor label cover gas piping? For example, if a gas water heater is moved and the contractor needs to extend the gas piping, or run a gas line off an existing inspected gas line future tee to a new fixture, does minor label cover these condition? Are there any situations when minor labels would cover gas line work? Thanks for considering our question.

A. No, the scope of work under plumbing minor labels does not include gas pipe installations. At some point in the future, the Tri-County Board may consider a mechanical minor label program. (Tri-County Code Forum, October 25, 2001)

2. Q. Can a minor label permit be issued for a single sink relocate if standard permits have been issued for electrical and structural?

A. Yes, if the installation meets the criteria for minor labels. (Tri-County Plumbing Code Forum, January 24, 2002)

3. Q: There are certain jurisdictions that allow a plumbing minor label to be used for the installation of a backflow device under certain limitations. Some jurisdictions just say no way. What is the determination of the code panel?

A: A testable and certified backflow device does not fall under the parameter of the minor label rules so a plumbing permit would have to be procured and an inspection performed. (Tri-County Plumbing Code Forum, July 25, 2002)

4. Q: Can a plumber use a plumbing minor label when replacing an existing leaking,gas hot water heater that is not a conversion?

A: Yes, a plumbing minor label can be used when changing a gas water heater, if the installation meets the criteria for a plumbing minor label. This forum cannot address permit issues in other code areas. (Tri-County Plumbing Code Forum, April 25, 2002)

5. Q If I am unable to attach a minor label to the electrical-service panel, because it hasn't been installed or its being replaced-where do I put it?

A. Place the minor label permit on the installation itself in a visible location and follow up with a note on the permit log sheet as to its location. (Tri-County Plumbing Code Forum, April 25, 2002)

6. Q.Is changing out a gas range covered under the minor label program?

A.No. (Tri-County Plumbing Code Forum, April 25, 2002)

Permits (Residential)

1. Q. When is it necessary to pull a permit to replace fixtures such as sinks and toilets? I find that in most jurisdictions there are no permitting requirements if I am changing out a toilet, but in one jurisdiction I am required to pull a permit to replace a toilet if the fixture is not exactly the same as the toilet I am replacing. Where are you going to find a 1924 toilet? And who wants one anyway? What is right?

A. For residential plumbing work, a permit is not required for the repair and replacement of toilets and sinks and other fixtures, or for repairs such as changing the trap to the sink or changing water stops. This means that a licensed contractor (or a qualified person; see administrative rules that follow) can replace an old toilet with a new, water efficient toilet without a permit as long as it is a straight replacement, and does not involve moving the fixture or altering the plumbing system in any way.

Residential water heater replacement, however, is not exempt. To repair or replace a water heater, plumbers must either use a minor plumbing label or pull a permit.

Oregon Administrative Rules are quite clear in exempting ordinary repairs and replacements from permitting requirements for residential plumbing work. OAR 918-780-0120 defines exempt ordinary minor repairs:

(1)(a) Exempt plumbing transactions. The following do not involve any changes or alterations of an existing plumbing system and are designated as "ordinary minor repairs" exempt from permits and inspections:

(A) Repair, replacement or maintenance of existing and accessible, fixtures, parts, appliances, appurtenances, related water supply and drain attachments; or

(B) Emergency repair or replacement of freeze-damaged or leaking concealed piping not exceeding three feet of new piping.

(b) "Ordinary plumbing repairs" do not include replacement of water heaters, and except as allowed by section (1) of this rule. Work inside of a wall, ceiling or underfloor; permanently concealed work or work to be permanently concealed.

(2) Scope of the exemption.

(a) "Qualified person." This exemption is only available when the work is done by a licensed and registered plumbing contractor, a licensed plumber in the employ of a registered plumbing contractor or person exempt from licensing.

(b) Permit and inspection. The exemption allows the work to be done without a plumbing permit and inspection.

(c) Code requirements. The plumbing product certification and One and Two Family Dwelling Specialty Code plumbing installation requirements remain applicable.

Stat. Auth.: ORS 447.072 & ORS 447.076

Stats. Implemented: ORS 447.072 & ORS 447.076

Hist.: BCD 17-1994, f. 7-21-94, cert. ef. 10-1-94

Note: For such installations in commercial, multifamily, a plumbing permit and inspection are required for all work involving fixture replacement whether the installation is performed by a contractor or not.

(Tri-County Code Forum, July 26, 2001)

Pipe in ground installation

1. Q. ABS and PVC DWV pipe normally has a warp or a bend. In ground installation, should the warp or bend be pointed up, down, or to the side?

A. The warp should be to the side in order to support the length of the pipe and to maintain a uniform grade. (Tri-County Plumbing Code Forum, January 24, 2002)

Pipe Strapping

Q: Under what circumstances can a nylon zip tie be used as a pipe strap for pex pipe?

A. This application can be used for bundling or securing, not supporting purposes, unless the zip tie is listed for that application. (Tri-County Plumbing Code Forum, October 17, 2002)

Relief Drain Pipe Requirements

Q. Does a CPVC relief drain require CPVC orange or yellow glue with purple primer? Is this the only acceptable combination?

A. One-step CPVC (gold-colored) glue does not require primer. (Tri-County Plumbing Code Forum, April 25, 2002)

Septic Systems

Q: Zoning codes require that private sewage disposal systems shall be connected to an approved septic system. Can a plumbing permit pass inspection if it does not meet the above criterion?

A. Yes, the building permit requires zoning approval, local jurisdictions address this situation by issuance of the building permit. The DEQ inspects and approves the septic system. (Tri-County Plumbing Code Forum, October 17, 2002)

Shower Valves

Q: Is a shower valve an "existing" fixture?

A: No, a shower is a fixture (see the definition "plumbing fixture") and a shower valve is a fixture fitting, which is a part of the "water supply system." (Tri-County Plumbing Code Forum, April 25, 2002)

Q: Does the access panel or escutcheon make the valve "accessible"?

A: Yes. "Accessible" is defined in the code in Chapter 2, and may require the removal of an access panel, door, or similar obstruction. An escutcheon is considered a similar obstruction. (Tri-County Plumbing Code Forum, April 25, 2002)

Q: If such a shower valve is accessible, is it permittable?
A:Yes. Although it is accessible, it is concealed in the wall and requires a permit to install or replace. (Tri-County Plumbing Code Forum, April 25, 2002)

Q: If a permit is required, can you use a minor label for the installation?
A: Yes. A permit is required and, when performing the installation in a one- and two-family dwelling, a minor label could be used. However, the work should be left exposed for inspection if an inspection is requested. It is not appropriate for the plumbing inspector to dismantle portions of a plumbing system for the purpose of making inspections. When access is required for inspections it should be provided by the property owner or installer. The installer should advise the homeowner how to prepare the escutcheon for inspection. (Tri-County Plumbing Code Forum, April 25, 2002)

Q: Is the plastic backing plate provided by the valve manufacturer, by itself with no connection to the structure, adequate support for a shower or tub and shower valve?
No, unless the plate is listed for that application. (Tri-County Plumbing Code Forum, October 17, 2002)

Trap Arm Offset

Q. Is it acceptable to offset a trap arm with a forty-five degree fitting to raise up to the fixture tail pipe on a vented line, as addressed in Section 1006.0?

A. Yes, Section 1006.0, allows exemption from the provisions requiring individual vents for each trap, including traps for floor drains, floor sinks, funnel drains, area drains, catch basins and receptors within a building discharging to a vented soil or waste pipe under specific conditions. Because of the depth of the building drain, often the provisions of Sections 910.5, Exception and 1001.4, come into play. To limit the length of the tailpiece the following installation methods should be used:

(Tri-County Plumbing Code Forum, October 17, 2002)

Vent Piping

Q: When a horizontal vent pipe reaches its maximum allowable length can it be increased in size at that point to extend its allowable length?

A. Yes. (Tri-County Plumbing Code Forum, October 17, 2002)

Vented Floor Sinks

Q: What fixtures are acceptable to drain into a vented floor sink without a primer under Section 1006.0?

A. Standard sink type fixtures, continuous use type. (Tri-County Plumbing Code Forum, October 17, 2002

Water heaters-elevation requirements

In December 2000, with clarification in March 2001, BCD issued an Inter Office Memo on replacement water heaters. We have run across a situation which we would like discussed at the forum. Section 117.2 exempts replacement water heaters from complying with several items except the requirement to be to have pilots, burners or heating elements and switches 18 inches above the floor level when installed in a garage.

We have several houses constructed in 1977 to 1979 which are split level and have electric water heaters in the garage. These units were placed on the garage floor which seemed to be standard practice for electric water heaters back them. The units are against an interior wall next to the electric furnace. In these houses there is a soffit about 20 inches above the water heater which extends for six feet in all directions.

It is not possible to raise these water heaters 18 inches. In order to raise the heaters they will have to be moved at least six feet. This will require replumbing the units and extending the electrical circuit. These costs will easily exceed the cost of the water heater and will be financially burdensome on the owners.

1. Q. The question for the forum is whether or not these units have to be elevated regardless of the cost and inconvenience?

A. Section 117.2 clearly requires that all water heaters are installed so that the point of ignition is at least 18 inches above the floor.
(Tri-County Plumbing Code Forum, January 24, 2002)

Water heaters-minor label questions

1. Q. A minor label was obtained for water heater replacement, then the entire house was re-piped on the water system. Does the contractor need a full permit to cover the water heater installation?

A. No, since the work began with the water heater replacement, a minor label covers that work. Later, if the customer adds to the scope of work, it is necessary to pull a permit appropriate to cover the additional work. In this case, the plumber would have to pull a full permit to cover replumbing the house, but the minor label covers the water heater replacement. (Tri-County Plumbing Code Forum, January 24, 2002)

Water Heater Relief Valve Discharge Piping

Q: May water heater relief valve discharge piping be connected together?

A. Yes. As long as the aggregate cross sectional area is met. (Tri-County Plumbing Code Forum, October 17, 2002)

Water Heaters Size

Q. What is the maximum size allowed for a residential water heater?

A. Domestic water heaters designed for heating potable water must be equipped with an approved pressure-relieving device and must not exceed a capacity of 120 gallons, a water temperature of 210F; 150 psi, or heat input of 200,000 BTU per hour. If a residential water heater exceeds these maximums under the plumbing code, a boiler permit and inspection may be required.
(See ORS 480.525).

Water Pipe Replacement - Lost Grounding

Q: When a plumber is asked to replace water pipe that has a ground strap to the electrical service panel, the electrical ground is lost and the ungrounded service becomes a hazard. Who is responsible for dealing with this situation?

A: The plumber should advise the homeowner that the electrical service is not grounded and a hazard exists. Upon discovery of this type of situation an inspector would/should notify the homeowner and an electrical inspector, to make sure there is follow up on the situation. (Tri-County Plumbing Code Forum, July 25, 2002

Water Service

Q. How do you size a water service to a structure that has a lawn irrigation system?

A. System should be sized using the largest zone as per GPM. (Tri-County Plumbing Code Forum, July 25, 2002

Water Testing

1. Q. What method and extent of testing is required for DWV piping on post and beam structures or floor joist systems?


  • A separate water test not required.

  • A visual inspection of the post and beam is required.

(Tri-County Code Forum, July 26, 2001)

2. Q. How is the water test, required by code on a DWV system, verified on new construction?

A. The following methods are acceptable:

  • Visual observation at vent pipe.

  • Audio test

  • The inspector's discretion to determine water level

  • Use of a pressure gauge

  • Use of a sight glass

(Tri-County Code Forum, July 26, 2001)

3. Q. 1&2 Family Dwelling Code. Reference: The One & Two Family Dwelling Code 3409.4 Testing. Upon completion of a section or of the entire hot and cold water system, it shall be tested and proved tight under water pressure not less than the working pressure under which it is to be used. The plumbers in our area say we are the only jurisdiction calling for a test on 1 piece PEX and CPVC water service prior to burial. Is testing before burial not a requirement in other jurisdictions. Can 1 piece PEX or CPVC water service be covered before it is tested and approved?

A. No, PEX or CPVP water service pipe must be inspected before covering, but the pipe may be covered before it is tested. As per code requirements, all piping must be inspected and approved for cover before it is buried. In cases in which water is not available for testing, or manufacturer's requirements prohibit air testing on some piping, the jurisdiction may allow the contractor to cover the pipe after approval by inspection, but before it is tested. Pressure testing, for example, can be performed at a later date. (Tri-County Code Forum, October 25, 2001).

4. Q. Is a water flow-test required for residential multipurpose fire-sprinkler systems? If it is, how should the test be performed?

A. No. (Water Testing)

Where a Plumbing Inspection Begins - Water Pump

Q While ORS 693.020(b) exempts the installer from being a licensed plumber on residential property provided the water pump equipment does not exceed 7 percent horsepower, Is a permit and an inspection required if the installer is the homeowner? What if the installation is made by a licensed plumber?

A.Please see Section 447.010, 447.020. A permit and inspection are required for any plumbing pipe installed beyond the pressure tank, whether installed by a homeowner or a licensed plumber. Inspectors should begin the inspection of the plumbing system at the outlet side of the pressure tank and continue through the plumbing water system. By definition in the plumbing code, the "building supply" is the pipe that carries the potable water from the water meter or other water source to a building. This is also defined as water service. The water service begins at the outlet of the pressure tank. (Tri-County Plumbing Code Forum, April 25, 2002)

Where a Plumbing Inspection Begins - Well

Q. The Plumbing Code defines the "Building Supply" for water as the water meter or other source of water supply to the building or other point of use or distribution on the lot. When the water is supplied by a well, where does the plumbing inspection begin?

A. The plumbing inspections begin at the valve at the outlet of the pressure tank. See the attached illustrations of the most common piping arrangements for pumped water supply systems. In both applications the source of water supply is the last valve.
(Tri-County Plumbing Code Forum, October 17, 2002)

Whirlpool and Standard Waste Lines

1. Q. When removing a tub and installing a new tub, is it required to upsize the waste line to two inches all the way to the stack, or just to the vent. Does it make a difference if the tub is a whirlpool or standard regarding the drain line?

A. Yes, although Table 7-3 of the Oregon Plumbing Code assigns a bath tub or combination tub and shower 1.5 inch trap and trap arm and a whirlpool tub a 2-inch trap and a trap arm. Section 301.1.4 of the Oregon Plumbing Specialty Code, covering existing buildings, gives the jurisdiction the discretion to allow deviation from the provisions of current code when making installations in existing buildings. Contractors wishing to deviate from current code, for example installing a whirlpool to a 1.5 inch waste line with 1.5 inch trap and trap arm must contact the jurisdiction first before making the installation so that the jurisdiction can determine if the installation will meet the health and safety requirements. (Tri-County Code Forum, October 25, 2001)

2. Q. Table 7-3 of the 2000 Oregon Plumbing Code lists the following fixtures along with the required trap and trap arm sizes and fixture units:

fixture Minimum size
trap/trap arm Fixture unit
private use
Bathtub or combination bath/shower 1-1/2" 3 fu
Whirlpool bath or combination bath/shower 2" 3 fu

Some plumbing inspectors in the Tri-County area are requiring that whirlpool bathtubs installed in private use bathrooms which are manufactured with 1-1/2" waste outlets be installed with 2" traps and trap arms. Since the "combination bath/shower" wording is common to both fixture listings, I am interpreting the intent as requiring a 2" trap and trap arm is installed only on those Whirlpool bathtubs or combination bath/shower fixtures manufactured with 2" waste outlets. Am I correct?
A. No, Table 7-3 does not address waste outlets as a determining factor in trap sizing. A standard bath tub/shower combination is allowed an 11/2 trap and trap arm. Whirlpool baths or whirlpool combination bath/showers are required to have a 2-inch trap and trap arm. In both instances, each tub type is assigned 3 fixture units. (Tri-County Code Forum, October 25, 2001).

Y Fittings

Q: On a test Y fitting, does the branch of the fitting, which needs to be capped after test, need to be tested? If so, how would that capped Y branch be tested in a multiple story building?

A. No. (Tri-County Plumbing Code Forum, July 25, 2002)


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