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CHAPTER 2 DEFINITIONS
1) (Q) While inspecting a lab set up for acid waste and vent piping in a medical office
building the inspector finds the acid waste piping system installed without the
minimum required vent sizing requirements for DWV per code. The inspector asks
for and receives the documentation on the engineered system. Should the
Inspector question the seal if a structural engineer seals the design document?
(A) Yes. Current code would require an engineer in his respective design profession to
seal the design. Under the 2012 Code it depends on whether the licensing board
deems them qualified by the state board of rules and regulations. 2009 code:
“licensed to practice in his respective design profession” New Code: “registered
and licensed to practice professional architecture or engineering as defined by
statutory requirements…………” Ref: 2012 NCPC. Chapter 2 definitions Registered
Design Professional
CHAPTER 3 GENERAL REGULATIONS
1) (Q) An engineer has designed a gray water waste recycling system, including all DWV,
located in the basement of a single family dwelling. The system is designed to
allow full flow throughout the system so the engineer has decreased the
minimum pipe sizes of the DWV associated with the gray water system to one
pipe size smaller than the minimum code would allow. Would this
installation be allowed per the 2012 NC Plumbing Code?
(A) No. “All drain, Waste, and Vent piping associated with gray water recycling
systems shall be installed in full compliance with this code. “Ref: 301.3, (2012)
2) (Q) A contractor is installing a rain water recycling system. His explanation to the
Inspector; he is connecting indirectly to the sanitary drainage system so he does
not have to use the code minimum sizing requirements for the plumbing piping.
Should the inspector pass the rainwater DWV system?
(A) No. The 2012 Code requires gray water and rain water recycling systems to meet
minimum code requirements for DWV. The drainage system cannot connect
indirectly to the sanitary sewer. Ref. 301.3, 2012 PC
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3) (Q) A plumbing contractor has installed a floor drain with a deep seal trap in the slab
at the bottom of an elevator shaft in a multi-story office building. The elevators
are all hydraulic type. Can this installation be approved under the 2012 code? Can
it be approved under the 2009 code?
(A) No. New code requires an oil water separator to be installed in the discharge line
of the floor drain. Ref: 301.6 (2012), 301.6, Exception. 2009 Code would not
require an OWS to be installed. Per research of hydraulic elevator fluid capacities
and spill probabilities an OWS will not be required by Mecklenburg County.
See Plumbing interpretations on the web site for current information.
4) (Q) The manufacturer of a new brand of AAV allows a 20 degree deviation from
vertical on the vents installed in an attic. If the plumbing code had a minimum
standard that only allowed an 18 degree deviation, which of the two installations
should be approved by the inspector?
(A) The code minimum shall be met because it is more restrictive. 301.7, Exception,
2012 PC
5) (Q) Upon inspecting the sanitary sewer and water distribution piping on a single family
home the inspector finds the piping covered up in the right of way. Is the inspector
required to inspect in the right of way or is he restricted to private property?
(A) Unless a utility contractor has already installed the water and sewer to the
termination point at the building the inspector is required to inspect the installation
from the cleanout at the house to the connection at the utility. Inspections are
required to determine compliance with 306.1 through 306.3, 2012 PC
6) (Q) The pump for a domestic hot water recirculation system is located below the
design flood elevation in the garage of a single family dwelling located close to the
ocean. Would this installation be allowed by the 2012 code?
(A) A pump for domestic water cannot be installed below the design flood elevation.
The exception allowing the pump in the 2009 code has been deleted from the
2012 code. Ref: 2012 code see item 2 is deleted from the exceptions. 2012 NCPC
[B] 309.2 Exception (deleted)
7) (Q) All permanently installed water closets in buildings are required to be in a separate
room or stall per the 2012 Plumbing Code. What are the two locations exempted
by the 2012 code?
(A) Child Care facilities and facilities where restraint is required per the building codes.
Ref: 310.4, exception 3, 2012 PC.
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8) (Q) An inspector is witnessing the testing of the plumbing system on a single family
dwelling. The dwelling has several shower installations. The inspector has turned
the job down because the plumbing contractor has not provided a shower pan liner
test. Is this a required inspection under the 2009 Plumbing Code? Is it a required
inspection under the 2012 Plumbing Code?
(A) The 2012 code test procedures require a shower pan test. REF: 2012 NCPC
312.9. The 2009 code did not address shower pan testing.
CHAPTER 4 FIXTURERS, FAUCETS AND FIXTURE FITTINGS
1) (Q) Can a mercantile occupancy use the code exception in 410.1 to eliminate drinking
fountains?
(A) No, Drinking Fountains are required in a mercantile occupancy once the occupancy
count exceeds 100. The exception for requiring drinking fountains in 410.1 only
applies to A 2 occupancy classifications which are restaurants, night clubs, taverns
and bars. Table 403.1 (See A-2 occupancy No. 1 and Mercantile occupancy No. 6
requirements in the 403.1 table) and 410.1, 2012 PC
2) (Q) Can we replace a bathtub with a walk in shower (only one bath room) in a condo?
(A) Yes the fixture tables will allow either a tub or a shower to meet the minimum code
requirements. Table 403.1 R-2 occupancy, PC 2012
3) (Q) I am trying to calculate the required number of toilet fixtures for a charter school.
As I understand things, the relevant information is as follows:
•
•
Charter schools are public schools authorized by the State Board of Education
Charter schools are exempt from most of the NC General Statutes that relate to
schools, including GS115C-301 which is referenced in the code.
• Charter schools have a maximum enrollment given in the charter. The charter is a
legal document between the NCBOE and the charter school that governs most aspects
of the school’s operation.
As I review the code, the relevant section of the 2012 NC Building Code appears to be
2902.6 Plumbing Fixtures for Public Schools. 2902.6.1 states that “Occupant content of
public schools for the purpose of determining the number of required facilities shall be
the maximum legal class size multiplied by the number of classrooms. Maximum class
sizes are 29 students for grades K-9 and 33 students for grades 10-12 (GS 115C-301). The
occupant load for private schools shall be as listed in Table 1004.1.1 of this code.”
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The issue that I have is that while charter schools are public schools and therefore would
appear to fall under this section, they are not bound by the NC General Statutes that
relate to class size. They are actually bound by the number of students listed in their
charter, which is typically far less than the maximum in the General Statutes. I would like
to use this number as the occupant content for the school for the purposes of
determining the number of required fixtures.
In my case, using the traditional calculation given in 2902.6.1, I would end up with 797
students, but the school’s charter caps the number of students at 442. Again, the charter
is a legal document that the school is bound to follow.
Barring this, it would be preferable to use the number of classrooms x (square
footage/20net) as is the method for private schools since this would more closely
approximate the actual number of students at the school than the method for public
schools in 2902.6.1.
(A) Even though this is a public school we would allow the calculation of the class
rooms for students to be calculated at the number of classrooms x (square
footage/ 20 net). This is a charter school and it is similar to a Montessori school.
These schools are unique when compared to a public school student populations
Your calculation would meet the table 1004.1.1 of the Building Code similar to
private schools in 403.9.1 PC 2012.
4) (Q) Can a commercial two compartment sink be used as follows:
Compartment A (left hand) waste is tied in indirectly for food prep. Compartment
B (right hand) waste is tied in directly for a pot sink per the 2012 code NCPC
802.1.8 Is this permissible?
(A) This is permissible. Each section of the sink may be considered separately for
DWV requirements to meet minimum code. Not prohibited by 418.
5) (Q) (1) Does 419.1, 2012 PC, require a waterless urinal to be supplied with a
permanent connection for a future water supply? (2) If yes, when I have
multiple urinals in a bathroom would a single water line stub out be acceptable
for all urinals or will each urinal requires a separate water line stub out?
(A) (1) Yes. 419.1 Exception. (2) Provide a future connection for each urinal separately
and/or approximately every 4 feet. 419.1, 2012 PC
6) (Q) An inspector is called to re-inspect an apartment that has been recently occupied.
It is one of the apartments in a newly completed complex of over 100 units. While
inspecting a new water connection he notices the water heater temperature is
set at 140 degrees. What should the inspector do per the 2012 code?
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(A) The inspector should inform the tenant, contractor and landlord that an anti scald
valve is required if the temperature is set above 120 degrees in the dwelling
units. Ref: 424.3, 102.9, 2012 PC
7) (Q) Does the 2012 code require “domed/elevated “floor drains in restaurant floors?
(A) No. The code has not changed. Floor drains should not present a tripping hazard
if they are in the path of travel or egress. (See also NC Building Code) 412, 2012 PC
CHAPTER 5 WATER HEATERS
Number 1 through 13 below is the specific code requirements related to water heaters
1) *See NC General Statutes/Administrative Code change-out permitting requirements
for one and two family dwellings (a) through (k) below*
a) The work is restricted to one or two-family dwellings only (no buildings with three or
more dwelling units and no commercial buildings).
b) The work has to be performed by a North Carolina Licensed Plumbing Contractor (or a
bona-fide employee of a North Carolina licensed Plumbing Contractor)
c) The licensee is required to personally examine the work at completion.
d) The licensee is required to ensure that a leak test has been performed on the gas
piping.
e) The energy use rate or thermal input is not greater than the water heater which is
being replaced.
f) The replacement is required to be installed in accordance with the current edition of
the State Building Code (plumbing section).
g) There is no change in fuel.
h) There is no change in energy source.
i) There is no change in location.
j) There is no change in capacity.
k) There is no change in routing or sizing of venting or piping.
* If any of the above requirements are missing, permits/inspections are required*
2) All water heaters (including electric), if either in a garage or a room leading directly off
a garage must be on a stand (ignition source elevated 18"- unless FVIR listed) and have
vehicle protection, if in the travel path of a motor vehicle as per the NCFGC or NCMC.
3) Gas water heaters must have a union or (flare fitting if copper), or a listed flexible gas
connector approved for the location on the gas line, as well as an appliance drip leg
that has a 90 degree change of direction in it (if not on the appliance MP regulator).
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4) Gas water heaters must have the venting attached per manufacturer’s instructions.
5) Electric water heater change-outs must have a means of disconnect (NEC Article 422)
6) All water heaters must have the manufacturer's clearances two sides, top, back, and to
combustible construction- this includes appropriate piping insulation for water piping
in unconditioned areas.
7) All water heaters must have approved dielectric unions/fittings on the water piping
(unless prohibited by manufacturer’s installation instructions).
8) Manufacturer’s Installation instructions must be left with the water heater.
9) On city water systems, an expansion tank must be added for a tank style heater, and
for a tank-less heater if the manufacturer requires it. A well supplied system may not
if it has an expansion tank on the well and no backflow devices.
10) T&P discharge lines may only serve a single relief device and shall not direct connect
to piping serving any other relief device or equipment and installed as per NCPC 504.6
11) Where water heaters or hot water storage tanks are installed in: (a) remote locations
such as a suspended ceiling, (b) attics, (c) above occupied spaces, or (d) unventilated
crawl spaces, the tank or water heater shall be installed in a galvanized steel pan
having a material thickness of not less than 0.0236 inch (0.6010 mm) (No. 24 gage), or
other pans approved for such use.
Exceptions:
a) Electric water heaters may rest in a high-impact plastic pan of at least 1/16 inch
(1.6 mm) thickness.
b) Water heater mounted on a concrete floor sloped to a floor drain. EG; equipment
rooms
12) Pan drains shall be no less than 1.5 inches deep in the pan, no smaller than 1 inch
diameter and will be constructed from materials listed in NCPC table 605.4
13) Discharge through an air gap located in the same room as the water heater, either on
the floor (if on concrete slab), into an indirect waste receptor or outdoors.
14) (Q) A T&P relief line terminates only slightly (the thickness of a piece of paper) above
the drain pan for a tankless water heater located in the attic of a three story
townhome. What is the proper height of the gap above the drain pan for the T& P
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relief line if the line is sized to meet minimum code? If the drain line is one inch or
more above the drain pan is splashing an issue that would allow a reduced height
for upper floor or attic terminations?
(A) 504.6 #5 would allow the discharge line from the T&P relief line to discharge into a
water heater pan. The code does not address the minimum height above the pan.
In 802.3.1 the code states that receptors shall be installed to prevent splashing.
The maximum height above the pan would be 6 inches but the minimum could be
as close to zero as the contractor wants to install the relief line. 802.2.1, 802.3.1,
504.6 #5, #6, #10, 2012 PC
CHAPTER 6 WATER SUPPLY AND DIDTRIBUTION
1) (Q) An underground combined water/fire service line is installed to supply both fire
sprinkler and potable water to a building.
A) Can the FDC (Fire Department Connection) to the building be installed on the
potable water side of the water service piping?
B) Is protection required for Fire Hydrants when branch lines are located on the
potable water supply line.
(A) A) No. The potable water shall be protected from the sprinkler water in the
building by a backflow device that meets the code. The combined line shall
meet the requirements of the State Plumbing Code first for protection, material
and testing. Once that has been done the Fire Code requirements shall be met.
Ref: 608.13
B) Yes. When Fire Hydrants or other Fire Apparatus are located on the potable
water supply and the main water line shall be protected from the turbid water
that is located in the water line to the hydrant by a backflow device meeting
minimum code. The backflow device shall be installed on the FDC branch as
close as possible to the branch connection to avoid turbid water from
entering the domestic water line and contaminating the potable water.
Ref: 608.5, 608.13
2) (Q) The specifications for a new commercial building call for Polybutylene (PB) water
service and water distribution pipe to be used on a project permitted under the
2012 Plumbing Code. Should the plans examiner approve this material?
(A) No. The 2012 code has removed PB from the list of approved material for water
service piping. Ref: Table 605.3, table 605.4, 2012 PC
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3) (Q) Sanitary Sewer piping cannot have restrictions to flow because of the waste buildsup and eventual clog resulting from the restriction either in pipe size reduction
or use of a fitting with shoulders that would disrupt flow. Would the 2012 code
require the same restrictions on water pipe fittings?
(A) Yes. “fittings shall not have ledges, shoulders or reductions capable of retarding or
obstructing flow in the piping.” Ref: 605.5, 2012 PC
4) (Q) Is cross link aluminum PEX allowed in the 2012 code for water distribution, water
service and fittings?
(A) Yes. See 605.21, 605.21.1, and tables 605.3, 605.4 and 605.5, 2012 PC
5) (Q) A Would a stop- and- waste valve be allowed under the 2009 code? B. Would a
stop-and –waste valve be allowed under the 2012 code?
(A) A. No. Not allowed 608.7 2009 NCPC
B. Yes. See 608.7 Exception NCPC Freeze proof yard hydrants that drain the
riser into the ground shall be permitted to be installed, provided that the
potable water supply to such hydrants is protected upstream of the hydrants
in accordance with Section 608 and the hydrants are permanently identified as
no potable outlets by approved signage that reads as follows: “Caution, Non
Potable Water. Do Not Drink.”
6) (Q) A backflow preventer is protected from freezing by the installation of unions
that are easily removed. Is this an acceptable means of protection from freezing
per the code?
(A) Yes. 608.14.2, 2012 PC.
7) (Q) A reduced pressure principal backflow preventer installed inside a building has
the relief port piping terminating in an air brake located outside the building. Is
this an acceptable termination per the code?
(A) Yes. As long as it is terminated outside the building. 608.14.2.1
8) (Q) What are the special piping material requirements for installing a NFPA 13 D
sprinkler system in a single family residence for a partial system? For a full fire
sprinkler system?
(A) There are no special material requirements for a partial system, standard water
piping per the North Carolina Plumbing Code is required if the installation is a
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partial add on system. 614.4 #4 2012 PC. A full 13D system would have to meet
NFPA 13D material requirements. 615.1 2012 PC
CHAPTER 7 SANITARY DRAINAGE
1) (Q) An engineering firm has submitted plans to construct a building with a large
meeting room located in a park in Mecklenburg County. The meeting room will be
rented by the parks department for meetings and social occasions. Neither the
parks department nor the health department (food services) will allow food to be
prepared on the site. The prep area contains a 3 compartment sink and a six
burner residential range with a type 2 hood. The waste for the building is drained
into a septic tank. Septic tank installations are required to be approved by the
Mecklenburg County Groundwater and Wastewater Dept. (GWWD) The
GWWD dept. will not require a grease interceptor on the site. The Code
enforcement department will require a point of use interceptor at the 3
compartment sink. The GWWD concludes the interceptor shall be installed
outside the building and meet their installation requirements. What should be
done to resolve the conflicts between the two departments?
(A) As with the minimum building codes the most restrictive requirements shall apply.
The grease interceptor is required it has to meet the minimum standards of both
the GWWD and the Mecklenburg County Code Enforcement Department code
minimums. The sanitary waste and vent system installation is required to be
permitted and inspected by the code enforcement department up to the
connection at the septic tank. Ref: 701.1, 701.2
2) (Q) In a residential single family dwelling that has 4 bathrooms with water closets, the
waste in the basement bathrooms is pumped to a lift station, the two upstairs
bathrooms drain by gravity. Would the main drain required be a 3 inch or a 4 inch?
(A) Even if the DFU’s calculation for the basement pump may allow a smaller main
drain if sloped at one quarter inch the main drain is required to be a 4 inch
because of the number of water closets discharging into the main drain.
Table 701.1 (1) footnote c, 2012 PC
3) (Q) What is the intent of adding the exception in the 2012 code eliminating the use of
PVC pipe and fittings for sanitary and storm sewer installations in high rise
buildings?
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(A) Bill Moeller, PE, DOI Chief Plumbing/Fuel Gas. Interpretation.
The intent was to limit the use of plastic pipe for drain, waste, storm water and
vent in walls and concealed spaces in buildings in which the top floor is over 75 feet
above the grade of fire department access. Therefore exposed fittings under sinks
could be plastic. Pipe and fittings in walls and concealed in ceiling spaces could not
be plastic for these types of buildings. This code language goes back to what was
used prior to adoption of the ICC codes.
Therefore (1) PVC can be used underground, (2) piping in an adjacent building less
than 75 feet to the highest occupied floor can be plastic, (3) run-outs from stacks
should be cast iron, (4) concealed construction should not be plastic, (5) under sink
fittings and traps can be plastic and (6) PVC washing machine boxes are not
concealed and can be plastic. Material installed between the floors such as Pro Set
is not allowed. Ref: 702.1 Exceptions, 702.4 Exceptions, 1102.2 Exceptions, 1102.7
Exceptions, 2012 PC
4) (Q) An AAV is installed on a plumbing vent. The AAV is specified from the
manufacturer for multiple applications. The 1(1/2) inch AAV may be installed
directly to a 1 (1/2) inch pipe (outside) or glued (inside) a 2 inch pipe. Does the
installation meet code and manufacturers recommendations?
(A) No. The manufacturer of the pipe will not allow gluing on the inside the pipe.
Ref: 702.4, 2012 PC
5) (Q) Can the inside of a PVC pipe be used as a fitting to glue a cleanout or a closet
flange?
(A) DOI interpretation, September 2011. No, Section 702.4 states "pipe fittings shall
be approved for installation with the piping material installed and shall comply
with the applicable standards listed in Table 702.4. Table 702.4, PVC fittings
reference ASTM D 2665, ASTM F 1866, ASTM D 3034, and ASTM D 2949. Other than
not meeting these standards, inside pipe diameters can vary significantly as the
wall thickness and outside diameter varies and therefore is not suitable for use as a
fitting socket. 702.4, 2012 PC
6) (Q) The water service has been completed on a project, however, while installing the
sanitary sewer line the contractor runs into a problem. FYI: (The water service
line is crossing the water line at 90 degree angle.) The water line installation will
not allow the proper slope on the pipe to meet the code per the DFU calculation.
The engineer wants to replace the 4 inch sewer line with an 8 inch line so the
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water service will not have to be re-done. With this fix the sewer line will meet
code per the slope requirement and miss the water service line. A. Would this
be allowed by code? B. If no. What are acceptable alternatives that will meet
code?
(A) A. No. 704.1 The “scouring velocity” of the piping cannot be maintained when
using an 8 inch pipe. B. To keep solids suspended a slope with a velocity of 2 feet
per second must be maintained. To use this alternate method the engineer will
have to provide calculations in a sealed letter that show the slope can be reduced
and still maintain the 2fps velocity required to meet minimum code. The 2fps
allowance is in the code commentary and the NCDNR site utility requirements.
The contractor can re-route the water line as an alternate to providing the
calculations. Ref: 704.1
7) (Q) What are the special provisions in the code for heat fusion joints for
Polyvinylidene floride plastic pipe and tubing joints and what test procedure in
required?
(A) Joint surfaces shall be clean and free of moisture. The joint shall be undisturbed
until cool. The joints shall be made per ASTM F 1673. 705.18.8 PC 2012
8) (Q) Can a side-inlet quarter bend be used for wet venting and stack venting?
(A) Yes. Deleted in the 2009 code but it is in the 2012 Code. 706.4, 2012 PC
9) (Q) The section on heel- or –side inlet quarter bends that was deleted under the 2009
code has been added back into the code 706.4. What is the conflict between the
new code article and footnote “f “in table 606.3? What has been added to the
footnote that effects the Quarter Bend installations?
(A) Per DOI we must use the most stringent requirement from all code sections that
apply. See DOI interpretation below as well as the most stringent
requirements that currently apply in the information listed below:
DOI Interpretation from Bill Moeller:
Section 706.4 was deleted in the 2009 plumbing code but was carried forward from the
IPC in 2012. This was a new section that was not deleted by the ad hoc committee and
was approved by the building code council. Since this was a new section it could not be
added to the errata and will stand as is until a building code change request is done and
submitted to the building code council. I have been advising those that ask about it, that
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in the interim we must use the most stringent of the two sections per section 102.1 of
the plumbing code.
There are other ways to work around not using the low heel inlet but they are not as
convenient or economical for plumbing contractors.
Jimmy Lawson is going to put together a code change request. When it is filed with the
code council, so that we get a real code change in the works, I will pole the ad-hoc
committee for their intent. If everyone on the ad-hoc committee agrees that section
706.4 was not intended to be in the approved 2012 plumbing code, I will issue an
interpretation based on the intent of the NC language on footnote f of 706.3.
The short answer is that the most stringent of both sections 706.3 and 706.4 are in effect
at the present time.
Current Code per DOI interpretation: 102.1, most stringent requirements.
706.4 Heel-or side-inlet quarter bends. Current requirements per 2012 code.
1) A quarter bend is an acceptable means of connection. Exception: They cannot serve
a water closet whether the quarter bends is a high-heel or low-heel inlet type.
(706.4)
2) A low- heel inlet shall not be used as a wet-vented connection (706.4)
3) Side-inlet quarter bends shall be an acceptable means of connection for drainage,
wet venting and stack venting arrangements. (706.4)
4) Quarter bend fittings used for change in direction “horizontal to horizontal” shall
only be permitted to be used as the first fitting directly behind the fixture for
fixture drains 2 inches and smaller, except clothes washers.
(Table 706.3 foot note e)
5) Except as noted in # (1) above the high-heel inlet of a quarter bend may be used as
a wet or a dry vent if the heel inlet connection of the quarter bend is located in the
vertical position. (Table 706.3 foot note f)
6) A side inlet connection may be used as a wet vent if the quarter bend is located
directly below a water closet or other fixture with one integral trap. (Note: Other
than a water closet a high- heel- inlet may be used as a wet vent on a fixture with
one integral trap.) (Table 706.3 f)
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7) A quarter bend, installed vertical to horizontal, except as noted in # (1) above, may
be used only within 12 inches below a water closet flange measured to the center
line of the quarter bend. (table 706.3 d)
10) (Q) 406.3 allows a 2 inch clean out for a 3 inch washer line. Is it acceptable to reduce
the size of all cleanouts by two pipe sizes?
(A) No. 406.3 is the only exception to 708.7 which requires the same nominal size for
the cleanout as the drain size until the size exceeds 4 inch at which time a 4 inch
may be used on sizes above 4 inch. Ref: 406.3 and 708.3.5, 708.7, 2012 PC
11) (Q) What is the DFU value and minimum trap size for a Shower when the total rate of
flow is 21.8 gpm? 709.1 PC 2012
(A) Table 709.1 2012 PC DFU 5, Min. trap size 3 inch.
12) (Q) What is the drainage fixture unit value when a waste receptor receives clearwater waste from a freezer?
(A) one –half DFU. 709.4.1
CHAPTER 8 INDIRECT/SPECIAL WASTE
1) (Q) A contractor is installing a service ware washing sink in a commercial kitchen. He is
connecting it directly to the drainage system. Is this allowed by code?
(A) Yes. The 2012 code allows a direct connection. 802.1.8 2012 PC
2) (Q) (1) is there a difference in a hub drain and a floor drain? (2) Do hub drains that are
flush with the floor level require a strainer? Example: Mechanical Closet.
(A) A floor drain is commonly used as a surface drain flush with the floor. A hub drain
usually supplies individual appliance drains piped directly to the hub drain without
a strainer. The hub drain that is cut off flush with the floor should have a strainer
installed. 802.3.2, 2012 PC
3) (Q) An indirect waste receptor (hub drain) is installed above a drop ceiling collecting
condensate from an air handler. Should the inspector approve or disapprove the
job under any or all of the following conditions:
a. The hub drain has a deep seal trap.
b. The hub drain has a deep seal trap and is trap primed from the tail piece of a
bathroom lavatory from the floor above.
c. The contractor installs a metered water line directly to the trap as a primer.
d. The hub drain is installed in a return air plenum ceiling.
e. The hub drain is accessible from a pull down stair.
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f. The hub drain is in an attic that has a permanent stair.
(A) (a-e disapproved) f. approved. Ref: 2009-802.3, 2012-802.3 “Ready access.”
CHAPTER 9 VENTS
1) (Q) Are vent stacks always required for every drainage stack that has five branch
intervals or more?
(A) No. A waste stack vent installed per 910 would not be required to meet the vent
stack five branch interval rules. 903.2 Exception, 2012 PC
2) (Q) A property owner has built a bathroom within 2 feet of the property line on the
side of his house which has been approved by zoning. A vent terminal is located 5
feet from the edge of the roof addition on a 2 in 12 pitched roof. Is this a code
violation?
(A) Yes. 904.5. (not within 10 feet of a property line), 2012 PC
3) (Q) Fixtures within a bathroom group are wet vented by a residential clothes washer
drain line that has been sized 3 inches to prevent sudzing action and allow for
free drainage in the system. Is the wet vent sized properly?
(A) 909.1, 2012 PC. A residential clothes washer drain line shall not be used as a
wet vent.
4) (Q) A group of fixtures on a circuit vent are discharging downstream from water
closet. 901.2.1 states that all fixtures discharging downstream from a water closet
shall be individually vented. Would this be allowed by code?
(A) Yes. 911, 2012 PC.
5) (Q) A circuit vent is installed that has eight fixtures four of which are water closets and
four are floor drains. A lavatory that is individually vented and two drinking
fountains that are common vented are upstream of the battery. Within the circuit
branch there are three urinals that are individually vented. (a) Are there any
special requirements for this circuit vent that would not apply to a standard circuit
vent? (b) Can a floor drain per 905.4 be used to vent the circuit using the
exception? [c] Are there any special conditions for the urinals located within the
circuit branch? [d] What would determine the size of the horizontal branch being
circuit vented? (e) Are the lavatory and drinking fountains allowed upstream of the
circuit vented branch drain?
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(A) (a) A relief vent is not required even though there are four water closets in the
circuit because this is a single floor and not a stack connection. 911.4 2012 PC
(b) No. this venting may be used for an individual floor drain or grease interceptor.
[c] The urinals fixture drains cannot be installed in the vertical they shall enter the
circuit branch drain on the horizontal only if installed within the circuit branch.
911.5 2012 PC
[d] The horizontal branch shall be sized for the total number of fixtures on the
branch. 911.3.1, 911.3 2012 PC
[e] Yes. They shall be individually vented. 911.5 2012 PC
6) (Q) A grocery store is using a combination waste and vent system to drain the clear
water waste from a group of coolers that run the entire length of one isle of the
store. A pump is being used to discharge water from a water bath for melons that
is being continuously circulated and re-charged with water. The pump is
discharging into the combination waste and vent line. The pump has a very low
gpm flow into the system. Would this be allowed by code?
(A) Yes. 912.2.2, 2012 PC. The low gpm would still allow adequate venting for the
combination waste and vent system.
CHAPTER 10 TRAPS, INTERCEPTORS, AND SEPARATORS
1) (Q) I am the plumbing engineer on the new Ralf and Sons restaurant. Does your
department size the grease interceptor for our restaurant? Can a hand sink be
indirect and go through the interceptor?
(A) Our policy is that the engineer sizes, specifies and seals the Grease interceptor.
We don’t get into interior vs. exterior; we just say that we require any drains such
as flat floor drains in the food prep area, pot sinks/3 compartment/food prep/
sinks/ & dishwashers are required to go thru the Interceptor. We request that any
clear water waste, i.e.: hand sinks/ice machine condensate in hub drains, go to
sanitary, to keep the size of the Grease Interceptor as small as possible. You should
specify a style of trap/interceptor and show your calculations, then seal it. Ref:
1003.3.1
2) (Q) An apartment clubhouse has two residential ranges. A type I hood is required over
the ranges. It is the intent of the owner to allow cooking for the tenants who rent
and use a large banquet room in the clubhouse. Should a grease interceptor be
required for this operation? Would a point of use interceptor be allowed if the
kitchen only has a pot sink and a three compartment sink?
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(A) Yes. The cooking in the clubhouse kitchen is not considered non intensive per the
interpretation on our web site and therefore will require at least a point of use
interceptor for each sink. 1003.3, 1003.3.1, 1003.3.4, 1003.3.4.1, Table. 1003.3.4.1,
2012 PC
3) (Q) In the example above if only one range is provided with a type II hood and the
cooking is sporadic and non intensive would a grease interceptor be required at the
two compartment sink in the Kitchen?
(A) If the kitchen facilities utilize a “standard” two compartment or single
compartment sink there is not a need for an interceptor if the operation is as
stated in the question. If they provide a pot sink in addition to the standard two
compartment sink or if the only sink provided is a commercial pot sink or three
compartment sink then we will require a point of use interceptor. (See interceptor
requirements for clubhouses in apartment complexes on the Meckpermit.com
web site.) No change of interpretation for the 2012 code.
CHAPTER 11 STORM DRAINAGE
1) (Q) I have a project for an outdoor pavilion that has a roof with a 1/8th inch per foot
slope to one side. The roof has short parapets. The roof drainage will be via the
parapet scuppers. Since the only plumbing related item is the roof drainage, would
they need a plumbing permit for this or will the building inspector handle the
inspection ?
(A) After discussing this with Gene Morton former Building CA and current Director of
Inspections the following information answers the question. The plan review
scupper sizing, location, materials, etc. is usually checked by the Plumbing
Reviewers. The Building inspector checks the installation. Information
from the Building Code and the Plumbing Code should be utilized by the Plumbing
Reviewer and/or the Building Reviewer to check the primary and secondary
scuppers. The Plumbing reviewer should coordinate with the Building reviewer.
Both codes have specific requirements that are critical to a code compliant
installation. Code Ref: (1106.3, 1106.4 1106.5, table 1106.5, 1107.1, 1107.2, 1109
NC Plumbing Code, 2012.) ([P] 1503.4, 1503.4.1, 1503.4.2, 1611.1, 1611.2, 1611.3,
3201.4 NC Building Code, 2012.)
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APPENDIX REQUIREMENTS
1) (Q) Does the 2012 code regulate swimming pool piping, process piping systems, utility
owned piping systems or rain water recycling systems?
(A) Only rain water recycling systems of the four listed. (Appendix C1 mandatory).
See also page VII.
GENERAL REQUIREMENTS, POLICY, ADMINSTRATIVE CODE
1) (Q) Water piping is being installed in an outside wall. Even though the water piping is
installed on the warm side of the wall insulation the inspector requires the pipe to
be insulated. Is this a code requirement?
(A) Generally not required. 305.6. Laundry rooms on exterior walls may have
insulation requirements because of the number of openings in the wall. If this is
the case the plumbing or the building inspector may require R6.5 to be installed in
the exterior wall. 101.3, 2012 PC, protection of the plumbing system.
2) (Q) I am adding a 3 compartment sink to an existing restaurant. I will supply a point of
use interceptor for the 3 compartment sink and a pot sink. Do I have to supply a
grease interceptor for the existing floor drains and can wash?
(A) No. We would not require you to chop up the floors to re route the plumbing to an
outside grease interceptor unless there is evidence of grease clog maintenance on
the drains in your building on a regular basis. You are either improving the situation
or protecting the added installation. Departmental Policy per 102.2, 2012 PC
3) (Q) Plumbing permits are currently required for repairs when breaking a trap seal
"Unsafe conditions", does this include all traps?
(A) Yes, permits are required for breaking ALL trap seals. (Admin 102.4)
4) (Q) The new 2012 plumbing code has words italicize in the code text. The 2009 did
not have this feature. A. What does it mean when a word within a paragraph in
the body of the code is italicized? B. It is confusing that some of the same words
that are italicized in one paragraph of the code text are not italicized in other
paragraphs. Did the code writer just miss some words and not others?
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(A) Page VI of the new code describes how to understand the italicized words.
A. When a word is italicized in the code text it means it has the exact meaning as
the definition in chapter 2 of the code.
B. If the word is in the definition but not italicized in the code text it does not
have the same exact meaning as the definition.
5) (Q) If the code has a bracket in front of the code text ([B] for Building Code for
instance) does that mean the Building inspector should enforce that section of the
code?
(A) No. The bracket beside the code text means a committee other than the
Plumbing Code change committee is responsible for the change. Enforcement is
still the responsibility of the plumbing plan reviewer or inspector.
6) (Q) Are service stations required to allow customers to use the plumbing facilities?
(A) NC law only requires that public restrooms are required if the occupancy has sit
down dining (hand washing) or in a public facility (Exp: government building,
train/bus station, etc.) This is a Department of Labor regulation. They are required
by law to be constructed per the NC Building code; however, NC Dept. of Insurance
and the Courts have ruled that outside of the above exceptions, if the owners
are denying access, the owner or his designee are well within their rights to deny
access and denial is lawful. Ref: See NC State Dept. of Labor rules and regulations.
General Requirements
7) (Q) Is a code official required to enforce the seal requirements of the North Carolina
Architectural and Engineering licensing boards?
(A) We require seals on plans per the NC Administrative code. We also may require a
professional seal under certain circumstances. Once violations of the state Board of
Professional Engineers and Architects are identified it is up to board officials to
enforce the rules and regulations. 204.3.5, 203.4.5.1, 2012 NC Administrative Code
8) (Q) A contractor wants to use a product called Ape Tape produced by Sioux City
manufacturing for bundling plumbing piping under a crawl space floor. The product
has been approved by IAPMO. Should the field inspector approve the installation?
(A) No. The product is not on the approved list on the ICC web site. We approve ICC-ES
test lab in most cases. See DOI comments from Bill Moeller, DOI Plumbing Chief.
303.4 PC, 2012
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IAPMO is not currently recognized by ICC to my knowledge. I agree that currently
anything accepted under an IAPMO report or certification would be an alternate method
and should be thoroughly reviewed by the AHJ prior to allowing the alternate method.
DOI does not approve materials or products outside of the scope of the ICC-ES approvals
or the standard list of testing agencies approved by DOI. We have issued letters in the
past indicating that certain products can be accepted by the local jurisdiction as an
alternate method. Whether the local AHJ accepts an alternate method is strictly up to
the AHJ.
The list current testing of approved testing agencies is for electrical and mechanical
devices and is administered by our chief electrical code consultant. I would need to know
a lot more about the IAPMO lab accreditations, testing procedures, quality control
programs, surveillance programs, ISO certifications and facilities before I could begin to
make an assessment as to their qualifications as a testing lab. In looking at the attached
IAPMO certification of listing, I have a few comments.
1. The marking requirements are more stringent than that required by our code. This is
good.
2. The installation instructions on page 2 contain 4 misspelled words and poor grammar.
3. The products are stated to comply with the latest ICC codes but fail to mention which
years are applicable.
4. The products are said to have been tested by an IAPMO R&T recognized laboratory
but fails to list what testing lab, the test report number and test date. A copy of the
test report would be good to have.
5. To be a valid test report the manufacturing facility for the product should fall under a
continuing surveillance program to assure that the tested products that were
approved are still manufactured under the same materials, methods and design that
was approved. The manufacturing facilities should be periodically audited by quality
control personnel to assure this. This is not mentioned in the report.
6. It might be prudent to audit IAPMO periodically to verify their processes comply with ISO
standards for record keeping, etc. if they become an approved lab.
7.
I hope this answers your question at least in part. Approval or recommendation of
IAPMO certifications and test reports will take careful evaluation and a better
understanding of their capabilities, processes and accreditations.
Bill Moeller
William H. Moeller, P.E.
Chief Plumbing Code Consultant
NCDOI/OSFM Engineering Division
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9) (Q) I am installing a double sink in the bathroom of a dormitory bathroom that serves
a suite of four rooms. This installation is repeated multiple times through 3 floors
of the dormitory building. The dormitory has a post tension slab and the
bathrooms had to be re-designed to meet handicap provisions. I cannot maintain
the required 30 inch center to center distance required for the lavatories because
an air handler is on one side of the lavatory top that we have reduced to 2 inches
but cannot reduce further or the air handler cannot be removed from the closet.
The other side of the lavatory is a 6 inch wall with the drains and vents for the
bathroom stacks that are sleeved through the post tension floor. We would like to
leave the two sinks for the convenience of the students so two can shave and get
ready for class at one time. We can maintain 27 inches center to center maximum
under the current conditions. The residential code would allow 24 inches center to
center for lavatories. Since this occupancy is very similar to a residential occupancy
would you consider allowing the reduced clearance between the lavatories for this
building?
(A) Under special circumstances where the Plumbing Official makes the
determination that the installation meets the intent of the code a condition such
as the one listed above may be approved on a case by case basis and for a single
occurrence where the modification will not lessen health, life, and fire safety
requirements. 105.1 PC 2012
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