Land Use and Environmental Service Agency
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December 2009
Quarter
Plumbing Q & A 2009
2)
3)
4)
5)
6)
7)
1
(Q) What does a contractor/permit holder have to supply for an
inspection?
(A) Section 107.2 of the NC Administrative Code states that it is the
duty of the permit holder “to provide access to and means for
inspection of the work for any inspections that are required by this
code.”
(Q) The Mecklenburg County inspection department preaches strongly
about how hard it works to combat inconsistency in inspections and
interpretations. When are you going to be consistent with other counties?
(A) Mecklenburg County Code Enforcement prides itself on
achieving a high level of consistency within the confines of
Mecklenburg County. We however do not have authority over other
counties or the decisions they render. We make interpretation
recommendations and/or requests to the NC Department of
Insurance from time to time and will continue to do so in and effort to
provide consistent code enforcement within “Mecklenburg County”.
(Q) Where are shower pans required?
(A) They are required on all showers with the exception of rinse
showers at swimming pools or beaches. Shower pans shall meet the
requirements list in section 417.5.2 of the NC Plumbing Code.
(Q) Are FROET roof drains permitted to be used in limiting the roof
penetrations on commercial roof drainage systems?
(A) Yes, provided that the designer uses the dual outlet type and the
separation of primary and secondary systems is maintained. The
primary system shall be sized per the more restrictive secondary
rate.
(Q) Does designated accessible hotel suites have to make the non code
required convenience shower, accessible?
(A) No, section 29.4.3.2 of the NC Accessibility Code states “tub OR
shower, not both.
(Q) Does the Code allow the use of paint or spray materials for a shower
pan liner?
(A) No! Section 417.5.2 allows the use of PVC sheet, CPE sheet,
sheet lead, sheet copper and preformed ABS.
(Q) May plumbing piping be routed within a 2 hour exit enclosure shaft?
(A) No.
2nd
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General:
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December 2009
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Plumbing Q & A 2009
9)
10)
11)
12)
13)
14)
15
(Q) What is the definition of “Core” plumbing facilities?
(A) These are restrooms centrally located directly off of an
accessible corridor with the quantity sized for the square footage of
the floor area it serves (one to two floors max.), taking into
consideration all of the occupancy types.
(Q) Is there an alternative for the rainfall charts listed in chapter 11 of the
NC Plumbing Code?
(A) Yes. Section 1106.1 allows for rainfall rates determined from local
weather data. Mecklenburg County has a chart developed from data
gathered from Mecklenburg County Storm Water Services. Designers
may use the chart provided they clearly identify its use on the
submitted plans. A copy of the chart may be obtained from the plan
submittal department.
(Q) When measurements differ between the approved set of plans and the
NC Accessibility Code, which takes president?
(A) The NC Accessibility Code. (ANSI A117 starting Jan 1, 2010)
(Q) Does the Accessibility Code require the handle of a urinal to be placed
on “the open side”?
(A) No!
(Q) Do locked faculty restrooms in schools require the lavatories to have
metering faucets?
(Q) Yes, all assembly occupancies.
(Q) Do small kiddy lavatories have to meet the accessibility code,
including wrapping of the trap?
(A) Yes
(Q) Do school class service sinks require trap wraps?
(A) Yes, if designated accessible.
(Q) What is the definition of plumbing minor repair?
(A) Minor repair is difficult to clearly define and is somewhat base on
the specific situation. The State Board of Examiners of Plumbing,
Heating and Fire Sprinkler Contractors defines minor repair:
d) Any connection, repair, or alteration which requires interruption of the potable water supply
and if poorly performed creates substantial risk of contamination of the potable water supply is
not a minor repair, replacement or alteration.
(e)
Any connection, repair or alteration which if poorly performed creates substantial risk of
fire or exposure to carbon monoxide, open sewage or other gases is not a minor repair,
replacement or alteration.
(Excerpt from GS 87-21c section .05.6)
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December 2009
Quarter
Plumbing Q & A 2009
16)
17)
18)
19)
(Q) What should be done to a discarded plumbing system when a building
is demolished?
(A) The sewer line/s should be permitted first, cut, capped and
inspected to prevent demolition debris from entering the sewer line
and fouling the city main.
(Q) What should be done to a discarded plumbing system when one or
more leased upfit spaces are demolished within a multi tenant building?
(A) A licensed plumbing contractor should obtain a permit, remove
and cap water lines, drainage and vent lines while assuring that vent
systems serving adjoining unit/s remain uninterrupted and there will
be no discharge of methane gas into a leased space. Call for
inspection!
(Q) What is HB 1409?
(A) House Bill 1409 is legislation that recently passed which exempts
a one and two family homeowner from required permits when
replacing electrical appliances, switches, receptacles or a water
heater (gas or electric) provided that there is no change in location,
voltage, capacity or amperage. The work is required to be performed
by someone licensed on GS 87-43 and/or GS 87-21.
(Q) May the water distribution line and the building sewer exit the through
the foundation wall through the same sleeve?
(A) No. Must be a separate sleeve.
3rd
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December 2009
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Plumbing Q & A 2009
3)
4)
5)
6)
7)
8)
9)
1
2nd
2)
(Q) Does a ejector pump tank, installed for the future, require the contents
(fluids) to be pumped prior to the final inspection?
(A) The pumping of the tank would be advisable, but it would be the
contractor’s discretion. However, the unused openings (vent, etc.)
need to be capped until they are used.
(Q) Does a residential fire sprinkler system require backflow devices?
(A) If the fire sprinkler system is separate from the plumbing
distribution system, then yes, a double check assembly would be
required.
(Q) What size/type water heater requires a safety pan?
(A) Section 504.7 does not exempt any type or size water heater or
tank from the requirement of safety pans.
(Q) What type of backflow protection is required on restaurant type
beverage dispensers?
(A) Beverage dispensers shall be protected by an air gap or a
backflow device meeting the requirements of ASSE 1022 or CSA
B64.3.1. Devices meeting these requirements are double check
design, usually stainless steel.
(Q) May two water heaters piped together be placed in an alcove, one in
front of the other?
(A) Yes, provided that both equipment’s controls are fully accessible
for service or replacement without removing the other water heater.
(Q) May a plastic pan designed for use with a tankless water heater be
used in an attic space?
(A) Yes, provided that the equipment’s distance to combustibles is
maintained.
(Q) May a contractor use Armorflex insulation to to insulate the water lines
feeding a gas fired water heater installed in an unconditioned space?
(A) Armorflex with an R value of 6.5 may be used to insulate the pipe
until it encroaches on the combustible clearance space so
designated by the equipment manufacturer.
(Q) May a disappearing stairwell encroach on the required service space
for a water heater installed in an attic?
(A) No.
(Q) Does a building whose water service is connected through a backflow
device, have to install an expansion device if the water heater used is of
the instantaneous type?
(A) No. There would be no thermal expansion.
3rd
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Equipment:
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December 2009
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Plumbing Q & A 2009
Equipment continued:
4th
(Q) Are connections for other fixtures or equipment allowed between a
water heater and its water service valve?
(A) No!
11)
(Q) Can you use a ¾” X1” pex adapter and a 1” pex pipe to install a t&p
discharge drain?
(A) The ones we have check did not seem to restrict the inside
diameter and would be approved. However not all fittings are the
same and there may be those that would not work.
12)
(Q) Would standing on a set of steps serve as the required access to a
water heater installed in an attic space?
(A) No
13)
(Q) When are thermal expansion devices required?
(A) These devices are required on distribution systems containing a
water heater and a backflow or check valve that would prohibit the
expanding water from backing up into the main OR if the water main
pressure exceeds the pressure rating of the T&P valve.
14)
(Q) May PEX pipe be used for the T&P discharge line?
(A) Yes.
15)
(Q) May the contractor install a water heater with ½” feeds when the
fixture demand does not exceed the limit for ½ “ pipe.
(A) Yes.
16)
(Q) Is it permissible to install the water heater drain pan drain using 1”
PEX pipe?
(A) Yes
17)9 (Q) May a water heater be turned so that the technician can stand on the
steps of a set of disappearing stairs to service the appliance?
(A) No. Section 502.3 requires a minimum of 30 X 30 inch platform in
front of the water heater’s control side for service.
3rd
10)
Land Use and Environmental Service Agency
(Code Enforcement)
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December 2009
Quarter
Plumbing Q & A 2009
2)
3)
4)
5)
6)9
(Q) What are the procedures for calculating the minimum number of
plumbing facilities?
(A) A brief explanation:
(Step 1) Divide the upfit space into its various uses using the NC
Building Code (i.e., assembly, business, storage, etc.)
(Step2) Using the particular use, the associated square footage and
the Building Code, obtain the number of people required for your
egress calculation. Continue until all spaces/uses are calculated.
(Step 3) Take these egress figures, divide by 2 to get a 50/50 split
between male and female and enter table 403.1 (NC Plumbing Code)
one sex at a time. Do the math. Take the total/s, from the various
uses and add them together for each fixture’s grand total. Round up.
This will be the fixtures TOTAL for the upfit. Repeat for each fixture
for both male and female.
This procedure is adequate for most occupancy uses but some types of
occupancies may require additional, more detailed analysis.
(Q) May the 67% rule (section 419.2) for converting water closets to
urinals be applied to the total male fixture count when there multiple
restrooms?
(A) No. The 67% rule is applied to each and every toilet room.
(Q) What water distribution protection is required for a baptismal pool?
(A)The distribution system may be protected by an air gap, an
atmospheric device or a double check assembly.
(Q) Do lavatories in a commercial kitchen have to be tempered?
(A) The plumbing Code only requires those fixtures serving the
public be tempered. The Health department does require the
lavatories in a kitchen to be tempered.
(Q) When does the exception in 504.7 apply?
(A) When the floor is concrete and slopped per section 412.5.
(Q) An architect is designing a space with an office/storage occupancy
type. May the designer add the unused office fixture portion to the storage
calculation before rounding up? May the designer also provide a letter
from the tenant declaring the quantity of staff for the storage use to further
reduce the calculation?
(A) Yes you may add the unused portion of the office calculation to
the storage use before rounding up. NC allows this perk. However,
the use of a letter is a different type of calculation. To use a letter
(per 403.3.1) you must calculate the number of employees based on
4th
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Fixtures:
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December 2009
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Plumbing Q & A 2009
the square footage first, then you may reduce this number by
application of the letter but, in no case less than 1 male and 1 female
restroom. These may then be added to the quantity of fixtures from
the office calculation.
4th
Fixtures continued:
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December 2009
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Plumbing Q & A 2009
2)
3)
4)9
(Q) Do car washes have to provide approved interceptors in the process
loop of recycled wash water?
(A) Designers wishing to clean recycled water (i.e., car washes,
steaming stations, pressure washing) with systems like the
Cyclonator, do not have to be on the approved interceptor list. The
Code does not apply to process piping, only discharges to the
sanitary sewer system.
(Q) May clear water waste such as a hand sink be installed on a greasy
waste line?
(A) The intent of the Code is to separate the waste however, if the
designer would rather incorporate the additional load on the
interceptor instead of adding a separate clear waste line, that would
be acceptable.
(Q) Do residential style washing machines used in occupancies such as a
doctor’s office, hair salons, or day cares, have to discharge through a
commercial lint interceptor?
(A) Occupancies that use commercial tumble machines or coin
operated machines would be better defined as a commercial laundry
operation and would require a lint interceptor. Occupancies that
utilize a residential style washing machine with intermittent use
would NOT be defined as a commercial laundry operation and the
filtering designed into the machine would be sufficient.
(Q) What is the crown weir of the trap?
(A) See picture.
4th
1)
2nd
Interceptors, traps & Special Waste:
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December 2009
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Interceptors, traps & Special Waste continued:
(Q) What is a plaster trap and how should it be connected?
(A) Plaster trap, plaster interceptor and plaster reservoir are used
interchangeably. To be used as the fixtures p-trap, the design would
not require more than 2 to 3 inches of water to form the seal.
Otherwise the device would require a separate external p-trap.
Plaster Trap
Plaster Reservoir
4th
5)9
Note: The use of flexible drain connectors is prohibited.
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December 2009
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Plumbing Q & A 2009
2)
3)
4)
5)
6)
7)
1
(Q) What are the stipulations, if any, on the replacement of drainage
piping on fire damaged structures?
(A) The damaged piping may be replaced with piping materials and
methods used at the time the structure was built. The only difference
would be penetrations through rated assemblies. These penetrations
are considered “life safety” and would have to meet the Code.
(Q) Is a drain required at a swimming pool rinse shower?
(A) A drain is not required unless the designer changes the scope of
the rinse shower to a shower for washing by the addition of hot
water.
(Q) What is the meaning of exception 5 of 708.10 of the NC Plumbing
Code?
(A) The exceptions are other acceptable ways to meet the
requirements for a C/O at the upstream end of a drain line. Exception
5 would allow a horizontally run line catching a fixture such as a
shower, to locate the C/O for that line on the fixtures vent as long as
it is above the fixtures flood rim.
(Q) Do we require a roof over a can wash located outside?
(A) No.
(Q) Does the plumbing code allow slopes less than 1/8” per foot?
(A) Yes the Code supports 1/16” per foot on 8” and larger lines.
NCDENR allows 1/16” on the large lines including 6” lines. We will
allow, as an alternative method, the uses of 1/16” per foot on 6” and
larger lines provided the engineer provides a sealed letter stating the
design load and slope will maintain a minimum 2 fps flow rate.
(Q) When can Fernco fittings be used?
(A) Section 705.18 allows the use fo connectors and adapters
consisting of elastomeric sleeve and stainless steel clamps when
joining dissimilar materials. The use of directional fittings (tee or
wye) is prohibited. The adapter coupling may be used above or
below grade.
(Q) May a contractor install a floor drain in a residential single family
garage with a sloped floor for the purposes of collecting run off from a
parked vehicle and direct that to a dry well or discharge above grade?
(A) Water Quality does not want drains which could convey oil
contaminants to the earth or water ways (streams). Drains in a
garage should therefore be connected to a sanitary sewer
connection.
2nd
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st
Drainage:
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December 2009
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Plumbing Q & A 2009
9)
10)
11)
(Q) What is the minimum depth for the pump discharge line on a whole
house sewage ejector?
(A) 12”
(Q) Exactly where does a condensate drain have to be located?
(A) It should be as close as possible to the appliance it serves but
accessible for priming. There may be other limitations depending on
where you choose to locate the drain.
(Q) What are the limitations on the use of a 4X3 closet bend?
(A) A 4X3 closet bend may be used directly below the closet flange.
There shall be no tee fittings between the flange and the bend.
(Q) May a condensate line discharge into a floor/hub drain located above
a drop in ceiling?
(A) The Code states:
802.3 Waste receptors. Every waste receptor shall be of an approved type. A removable strainer
or basket shall cover the waste outlet of waste receptors. Waste receptors shall be installed in
ventilated spaces. Waste receptors shall not be installed in bathrooms or toilet rooms or in any
inaccessible or unventilated space such as a closet or storeroom. Ready access shall be provided to
waste receptors.
Definitions:
READY ACCESS. That which enables a fixture, appliance or equipment to be directly reached
without requiring the removal or movement of any panel, door or similar obstruction and
without the use of a portable ladder, step stool or similar device.
12)
No!
How do you measure the distance stipulated in 802.4?
(A) You measure the vertical distance from the weir of the trap to the
bottom of the washer box, not down the center line of the pipe.
4th
8)
3rd
Drainage continued:
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December 2009
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Plumbing Q & A 2009
Venting:
1)
2)
2nd
3)
(Q) Does the Code allow the use of a combination instead of a sanitary
tee in a waste stack catching a lavatory or sink?
(A) Table 706.3 would suggest that a combination may be used in
any position in the direction of flow. However, section 906.2
stipulates that a fixture branch may not exceed it’s hydraulic
gradient and therefore would prohibit the use a combination in this
situation.
(Q) Does the Code still require that water closets back to back be installed
with a double combination?
(A) The 2006 Code required the use of a double combination on back
to back water closets. The restriction was removed in the 2009 NC
Plumbing Code.
(Q) In the drawing 802.2.2 (2) of the 2006 NC Plumbing Code
Commentary a floor drain (no trap) is discharging above the trap seal of a
second floor drain. Is this installation legal?
4)
(A) This installation may be used with receptors receiving
condensate and clear water drips and is approved on a case by case
basis. When allowed, the maximum distance shall not exceed 25’.
(Q) There seems to be some discrepancy with the enforcement and
understanding of section 909.4 of the NC Plumbing Code (2009). When
will the code as written be enforced?
(A) We will additional in house training to get Plan Review and Field
up to speed. Permits issued after Sept 1, 2009 should be in
compliance.
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December 2009
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Plumbing Q & A 2009
6)
7)
8)
(Q) Will the 2009 NC Plumbing Code allow the use of AAV’s in acid waste
systems?
(A) Section 917.8 prohibits installation of AAV’s in nonneutralized
special waste systems (acid) or supply or return air plenums.
(Q) Does the 2009 NC Plumbing Code require floors without plumbing (i.e.
parking decks, etc.) when calculation relief vents?
(A) No.
(Q) May AAV’s be placed outside the building?
(A) They must be installed per manufacturer’s instructions. Two of
the ones I checked have maximum cold weather limitation of - 40
degrees. PVC should not be installed in direct sun light.
(Q) May you install a single branch with two traps (fixtures) on a vertical
combination waste and vent system?
(A) Vertical combination waste and vent systems are designed to
have each trap connect individually to the vertical stack. A branch
with more than on fixture trap would have to be conventionally
vented and the load would be accounted for in the stacks total.
4th
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2nd
Venting continued:
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December 2009
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Plumbing Q & A 2009
3)
4)
5)
6)
3rd
2)
(Q) May a contractor use CPVC water distribution piping in HVAC return
air plenums?
(A) Plastic water piping may be used in return air plenums provide it
meets the requirements of section 602.2.1 of the NC Mechanical
Code which requires that material located in a return plenum have a
developed flame/smoke index of 25/50 or less (in accordance with
ASTM E84). Not all CPVC products will have the required index
rating.
(Q) Does a CPVC hot water loop have to be insulated?
(A) Yes (per 2009 NC Energy Code). The hot water loop (not the run
outs) must be insulated with 1” insulation having a btu transfer rate
not exceeding 0.27 per foot.
(Q) Do shower valve replacements require permitting and inspections?
(A) Yes
(Q) What does the new 2009 code require for insulating hot water
recirculating loops?
(A) The 2009 Energy Conservation Code requires:
Residential:
Section 403.4 requires that circulating loops be
insulated with a minimum of R-2 insulation.
Commercial:
Section 504.5 requires insulation of 1” with a thermal
conductivity not exceeding .27 Btu per inch.
(Q) What is the proper way to ground a replacement water service?
(A) When replacing a water service, the plumbing contractor must
take care not to interrupt the electrical system’s ground. Some older
homes used the metallic water distribution system along with the
metallic water service as the electrical system ground. Now with the
introduction of so many varieties of approved plastic piping
materials, other means of grounding are required. When replacing a
water distribution system or water service with plastic piping
material, a licensed electrical contractor should be contacted to
assure that no electrical hazards are inadvertently introduced.
(Q) When does a contractor have to install an expansion device per
section 607.3 of the NC Plumbing Code?
(A) There has been a slight interpretation modification from previous
opinions. The current school of thought is an expansion device
would not be required if there are no devices (backflow, check valve,
4th
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2nd
Water Distribution:
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etc.)
December 2009
Quarter
Plumbing Q & A 2009
installed in the water service that would prohibit the expanding water
from backing up into the main and the main pressure is less than 80
psi. The distribution system shall not be subjected to pressures
higher than 80 psi or a pressure reducing device would be required.
PRV’s with a bypass would let the pressure be absorbed by the main
but would subject the distribution system to pressures greater than
the Code required maximum of 80 psi.
Note Effective January 1, 2010, the installation of a PRV in the water
distribution system will require the installation of an expansion device
complying with section 607.3 of the NC Plumbing Code.
4th
Water Distribution continued: