Land Use and Environmental Service Agency
(Code Enforcement)
Attention: 3 Denotes a new question!
z Denotes a revised/revisited question.
Quarter
Mechanical Q&A 2009
May 2009
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(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) An existing home with a package unit, installed prior to the
requirement for lintels where the duct penetrates the foundation wall is
being replaced with equipment and duct of the same size. Would a lintel
have to be installed at this time?
(A) No, provided there is no increase in size of the foundation
opening.
(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) What is the inspection department’s policy on wearing hard hats on
construction sites?
(A) We are to wear hard hats anywhere job sites are posted “Hard
Hat Area”!
(Q) Is a permit and inspection required when replacing or installing a free
standing appliance?
(A) Yes, if the appliance is directly connected to the building utilities
and just plugged into an outlet.
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General:
Land Use and Environmental Service Agency
(Code Enforcement)
Attention: 3 Denotes a new question!
z Denotes a revised/revisited question.
Quarter
Mechanical Q&A 2009
May 2009
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(Q) Are hinges required on roof mounted exhaust fans (506.5.3)?
(A) If the exhaust system has code approved cleanouts and removal
of the exhaust fan for duct cleaning is not necessary, then a hinge
would not be required.
(Q) Does equipment installed in an enclosure, accessed by a louvered
door, have to be supplied with a high and low combustion air duct?
(A) The louvered door can not be used to meet the combustion air
requirements (per DOI). Transfer ducts or ducts to the outside are
acceptable.
(Q) Is a well acceptable to achieve the termination (clearance to grade)
requirements on a downdraft exhaust for a domestic range?
(A) In cases where there is no possible alternative to achieve the
required clearance to grade, a well with positive drain to open air
may be provided.
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Equipment:
Land Use and Environmental Service Agency
(Code Enforcement)
Attention: 3 Denotes a new question!
z Denotes a revised/revisited question.
Quarter
Mechanical Q&A 2009
May 2009
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(Q) May a contractor use the merchant coupling provided with each stick
of gas pipe, to assemble the permitted gas piping system?
(A) The NC Gas Code does not prohibit the use of all thread
merchant couplings.
(Q) How many gas tests are required for a single gas pipe installation?
(A) The Code would require two tests. One before you cover the work
and one on final inspection. We require an additional test if you
would like “temporary heat” which would result in a total of three.
(Q) Does gas piping have to be steel where the piping terminates at the
meter?
(A) The Code does not require a steel termination, but many gas
utility providers (Piedmont Natural Gas) will refuse to connect to
CSST or copper piping.
(Q) May the valve for a free standing range be placed behind the range?
(A) Yes. The valve is for servicing and does not have to be placed
where it can be accessed without moving the appliance.
(Q) Does the Code require a cut-off to be placed at the base of decorative
gas yard lights?
(A) Yes! The light is considered an appliance and would require a
cut-off within 6 feet and accessible (box/vault).
(Q) What is the minimum length for an appliance drip leg (sediment trap)?
(A) Drip legs shall be a minimum of 3” long or per the equipment
and/or regulator manufacturer’s installation instructions, whichever
is greater.
(Q) How do you test a new gas line extension or branch, added to an
existing gas line within the structure?
(A) Section 406.1.3 (2009 NC Gas Code) states that only the new
branch has to be tested. Section 406.1.4 states that you must use
two valves in series with a telltale piece, with valve, between the two
valves to vent any pressure.
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Gas Piping:
Land Use and Environmental Service Agency
(Code Enforcement)
Attention: 3 Denotes a new question!
z Denotes a revised/revisited question.
Quarter
Mechanical Q&A 2009
May 2009
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(Q) What does the new 2009 Energy Code require for duct insulation?
(A) Section 403. of the NC Energy Code states residential supplies
and returns shall be R8 in unconditioned areas. Duct running
through the web of floor truss systems may be R6 to limit duct
compression. Duct installed between conditioned floors need not be
insulated provided there is no condensation. Commercial supplies
and returns shall be R5 in unconditioned areas. Commercial outside
duct shall be R8.
(Q) The new 2009 NC Mechanical Code requires that grease duct be
tested with a light. How will this be accomplished?
(A) The contractor/installer shall call for an inspection after the job is
ready for inspection. The ladders should be in place, the drop
cord/light shall be fished through the duct and any obstacles such as
fans or grills that might obscure the inspection shall be removed.
The light inspection will commence upon arrival. Should the
contractor have concerns about open duct or would like the
inspector on the job for more time, the contractor may secure an
inspection by appointment (Call J. Aidoo (704)353-1273).
(Q) What are the new requirements for duct wrap on type I grease exhaust
in lieu of shaft requirements?
(A) In January 2009 UL, OPL and ICC-ES withdrew the listing and
Legacy reports for enclosure materials that used UL1978 as the
basis for approval instead of the more appropriate ASTM E2336
standard. Projects with permits issued on or after May 1, 2009 will be
required to meet the ASTM E2336 standards.
(Q) Is flex duct allowed in a residential garage?
(A) HVAC systems whose equipment room is located within the
garage shall be constructed of metal (26 gage, Minimum) for all
portions located within or penetrating the rated floor or ceiling.
Systems that serve the living area shall not supply or return from the
garage. Systems dedicated to the garage with not portions
penetrating the rated enclosure may be of duct board or flex duct.
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Duct: