Existing Type I comments.pdfCity of Edmonds
PLAN REVIEW COMMENTS
BUILDING DIVISION
(425) 771-0220
DATE: October 4, 2017
TO: Randy Steenerson
rsteener(2hotmail. com
FROM: Chuck Miller, Plans Examiner
RE: Plan Check: BLD2017-0993 - post -permit issuance site visit
Project Address: 22814 100th Avenue W
Project: Amata Thai restaurant
Scope: Determination of viability in maintaining existing Type I hood/components
and installation for continued use.
The initial proposal under the permit submittal was to maintain the use of the existing Type I hood
utilized by the former tenant as part of other work to be done as a tenant improvement. The
considerations given by the City of Edmonds Building Division for approving the proposal were as
follows:
The initial installation of the Type I hood was permitted and approved by the Building
Division/Fire Department.
The type of cooking appliances (presumably `heavy-duty' cooking appliances — see
International Mechanical Code (IMC) 507.5 and Chapter 2) were not indicated on the plans
as being changed.
Any changes to the placement of the cooking appliances (to accommodate the desires of
the cook/chef, type of food to be prepared, etc.) that would affect the placement/type of the
hood suppression nozzles would be addressed under a separate permit required for all fire
suppression system installations and alterations.
The greatest concern that came to light during the review of the proposed work was of the `existing'
wall construction behind the area of the cooking appliances and the Type I hood serving them. The
presence of combustible wall framing requires specific measures to be taken to meet the `clearance
to combustibles' requirements of 2015 IMC 507.2.6, 1982/1985 Uniform Mechanical Code (UMC)
Section 2003(d), and National Fire Protection Association (NFPA) 96 — Standard for Ventilation
Control and Fire Protection of Commercial Cooking Operations. The requirements to resolve those
concerns were incorporated into the submitted plans and approved.
Subsequent discussions specifically regarding the `existing' Type I hood brought new concerns to
light. After making a visit to the project site (presumably at the request of the owner/owner's
representative) a mechanical systems professional with experience in the installation of Type I
hoods and their requirements contacted the Building Division to address the following:
• The viability of the `existing' hood and the associated fire suppression system installations,
of such designs that currently many other jurisdictions require them to be removed.
• That, in removing the `existing' hood and associated components to complete the work
required to meet the `clearance to combustibles' requirements (at the time of the initial
installation as well as currently), the work to follow would essentially be of that for a `new'
installation — and of a hood/suppression system that would not meet the requirements of a
`new' installation.
A review of the construction permit documents for the initial installation of the Type I hood under
permit BLD1986-0119 did not provide much relief from the current concerns. Specifically noted by
the Building Official on the document regarding the `fire department review dated 2-20-86' were
the required `progress inspections'. On the very same day of the review an inspection by the
Building Official and the City Fire Marshal was performed, and on the permit it was noted that the
"installation was complete and finish applied to duct shaft prior to inspection.". While the Building
Official indicated that he did not observe any apparent code violations, his indifference or ignorance
of the requirements can clearly be seen in the deficient methods used to verify code compliance.
The apparently successful `in-service' use for the past 30 years is not to be diminished, and it
reinforces the importance of regular maintenance/cleaning of Type I hoods.
However, in consideration of all of the above, to avoid knowingly perpetuating an installation not in
compliance and done without the proper inspection, the following measures were taken:
• All work regarding the `existing' hood and associated fire suppression system installations
was stopped to avoid the undertaking of unnecessary measures or duplication of effort that
may fall short of meeting compliance with applicable codes.
• A site visit was made on Tuesday, October 3, 2017 to determine the viability of the
`existing' construction and hood installation proposed under permit BLD2017-0993 in
meeting code compliance. Those in attendance were; Chuck Miller - City of Edmonds Plans
Examiner; Paul Brough — Deputy Fire Marshal; and Randy Steenerson — Amata Thai
business owner.
The following written determination is intended to document the state of compliance of the
`existing' elements and those measures necessary (in `bold type') to achieve compliance with the
applicable codes.
• Regarding the `existing' wall construction:
The wall along the west side of the proposed project was constructed using 2x6 studs @ 16"
on -center with 2 layers of 5/8" `type V gypsum wallboard under permit BLD1983-0304 to
serve as a 2-hour fire -resistance rated area separation wall. It appears to be in satisfactory
condition with minimal through -penetrations of electrical metallic tubing and copper
plumbing piping. The penetrations observed just below the roof framing at the north -
most end of the wall have not been protected and must be provided with firestopping
per IBC 714.3.1.2. The annular space of the penetrants appears to be larger than that
typically accommodated solely by the use of fire caulk, requiring the use of alternative
methods/products. The entire extent of the wall was not visible at the time of the above
noted site visit but must be examined for additional penetrations and verification of
Page 2 of 4
appropriate firestopping to maintain the integrity of the fire -resistance rated wall
assembly.
• Regarding the `clearance to combustibles':
The wall framing noted above required that every portion of the Type I hood installed was,
at a minimum, 18 inches from the combustible construction unless a clearance reduction
method was utilized to reduce the required distance per UMC 2003(d). The presence of the
2-hour fire -resistance rated area separation wall along with an installation of `segmented'
stainless steel panels with a 1-inch `stand-off behind the Type I hood and the appliances
appear to have complied with the requirements at the time for a reduction of the clearance to
3 inches. However, both the Type I hood and the cooking appliances appear to have been
placed directly against the stainless steel panels, closer than that allowed. The current
requirements using the same method for the reduction of `clearances to combustibles'
specifies a minimum allowable distance of 6 inches for the installation of a Type I hood
per IMC Table 308.4.2. The distance between the Type I hood and the combustible
wall framing may be further reduced to that allowed by the terms of installation of a
listed and labeled Type I hood. The clearance at the cooking appliances is to be
maintained by the installation of a metal `L' bracket as noted on sheet `A1.0' — Note 7
— of the plans for work to be completed under permit BLD2017-0993. The distance
between the cooking appliances and the combustible wall framing may be further
reduced to that allowed by the terms of installation of listed and labeled cooking
appliances.
• Regarding the `existing' Type I hood':
The `existing' Type I hood appears to have complied with 1982/1985 UMC Sections
2003(a) through 2003(c) and Section 2003(e), which mostly regard the materials,
construction, and configuration of the various elements comprising the hood itself.
Unfortunately, the installation of the Type I hood did not maintain the minimum `clearance
to combustibles' per UMC Section 2003(d) as noted above, and the canopy size and
placement over the cooking appliances did not comply with that required per UMC Section
2003(f). The concern regarding the `clearance to combustibles' may be resolved by
removing the `existing' Type I hood and reinstalling it as required above. The
deficient size of the hood will require significant modifications to achieve compliance
or may warrant a complete replacement, a decision to be made by the business owner.
In any instance, a separate permit will be required for review and inspection of the
reinstallation of the `existing', or installation of a new, Type I hood to verify
compliance with IMC Section 507.
• Regarding the `existing' grease duct serving the `existing' Type I hood:
The only portion of the grease duct that could be seen during the site visit on October 2,
2017 was that from the top of the Type I hood to where is penetrates the suspended ceiling
system. Beyond that point, it was enclosed by what appeared to be fire -resistance rated shaft
construction intended to meet the requirements of UMC Section 2002(d). As noted earlier,
at the time of the original installation of the shaft the "installation was complete and finish
applied to duct shaft prior to inspection.", making it impossible to verify the required
Page 3 of 4
minimum distance between the grease duct and the enclosure per UMC Section 2002(d).
That, the measures taken to resolve the concerns noted in the above `bulleted' comments,
and the current grease duct shaft enclosure requirements of IMC 506.3.11.1 eliminate the
viability in maintaining the use of the `existing' grease duct enclosure. The installation of
a `new' shaft or field -applied enclosure of the grease duct will be completed as part of
that under the separate permit for the reinstallation of the `existing', or installation of
a new, Type I hood.
• Regarding the `existing' fire suppression system:
The fire suppression system required for a Type I hood appears to be an appropriate, well -
maintained, `UL 300' listed system in compliance with NFPA 96. To maintain the
integrity of the system, a separate permit will be required for review and inspection of
the re-piping/reconfiguration of the piping and/or nozzles to accommodate the
alteration or replacement of the Type I hood and the cooking appliances it serves, and
the other measures noted above necessary to achieve compliance with applicable codes.
In summary, in addition to permit BLD2017-0993 for other work to be done as a tenant
improvement, two separate permits must be obtained. One for the reinstallation of the
`existing', or installation of a new, Type I hood, and one for the re-piping/reconfiguration of
the fire suppression system piping and/or nozzles to accommodate the alteration or
replacement of the Type I hood and the cooking appliances it serves. The applications must
clearly indicate, and the plans represent, the use/re-use of `existing' elements and the
proposed work to be performed to comply with the applicable codes.
Page 4 of 4
2002 UNIFORM MECHANICAL CODE 1982 EDITION 2002-2003
(b) Prevention of Grease Accumulation. Duct systems serving a Type I hood
shall be so constructed and installed that grease cannot become pocketed in any
portion thereof, and the system shall slope not less than '/4 inch per lineal foot
toward the hood or toward an approved grease reservoir. Where horizontal ducts
exceed 75 feet in length the slope shall be not less than 1 inch per lineal foot. When
a centrifugal fan is used it shall be positioned so the discharge outlet is in a bottom
horizontal position and the air shall be so diverted that there will be no impinge-
ment on the roof, other equipment or parts of the structure.
(c) Cleanouts and Other Openings. Duct systems shall not have openings
therein other than those required for proper operation and maintenance of the
system. Any portion of such system having sections inaccessible from the duct
entry or discharge shall be provided with adequate cleanout openings. Cleanout
openings shall be equipped with tight -fitting doors constructed of steel having a
thickness not less than that required for the duct. Doors shall be equipped with a
substantial method of latching, sufficient to hold the door tightly closed. Doors
shall be so designed that they can be opened without the use of a tool.
(d) Duct Enclosure. A duct serving a Type I hood which penetrates a ceiling,
wall or floor shall be enclosed in a duct enclosure from the point of penetration to
the outside air. A duct may only penetrate exterior walls at locations where
unprotected openings are permitted by the Building Code. Duct enclosures shall
be constructed as the Building Code requires shaft enclosures to be constructed.
Duct enclosures shall be of at least one -hour fire -resistive construction in all
buildings and shall be of two-hour fire -resistive construction in Types I and II fire -
resistive buildings. The duct enclosure shall be sealed around the duct at the point
of penetration and vented to the exterior through weather -protected openings. The
enclosure shall be separated from the duct by at least 3 and not more than 12
inches and shall serve a single grease exhaust duct system.
(e) Fire -resistive Access Opening. When cleanout openings are located in
ducts within a fire -resistive shaft or enclosure, access openings shall be provided
in the shaft or enclosure at each cleanout point. These access openings shall be
equipped with tight -fitting sliding or hinged doors which are equal in fire -
resistive protection to that of the shaft or enclosure.
(f) Air Velocity. Duct systems serving a Type I hood shall be designed and
installed in a manner to provide an air velocity within the duct system of not less
than 1500 feet per minute and not to exceed 2500 feet per minute.
(g) Separation of Duct Systems. A separate duct system shall be provided for
each Type I hood, except that a single duct system may serve more than one hood
located in the same story of the building, provided that all hoods served by the
system shall be located in the same room or adjoining rooms; portions of the
interconnecting ducts shall not pass through any construction which would
require the opening to be fire protected as specified in the Building Code.
(h) Clearances. Exposed duct systems serving a Type I hood shall have a
clearance from unprotected combustible construction of at least 18 inches. This
clearance may be reduced to not less than 3 inches, provided the combustible
134
construction is protected with material required for one -hour fire -resistive
construction.
(i) Exhaust Outlets. Exhaust outlets for ducts serving commercial food heat N
processing equipment shall extend through the roof unless otherwise approved by
the building official. Such extension shall be at least 2 feet above the roof surface,
at least 10 feet from any adjacent building, adjacent property line or air intake
opening into any building, and shall be located at least 10 feet above the adjoining
grade level.
EXCEPTIONS: 1. Exhaust outlets for ducts serving commercial food heat -
processing equipment may terminate not less than 5 feet from any adjacent building,
adjacent property line or air intake opening into a building if the air from the exhaust
outlet is discharged away from such locations.
2. Upon approval of the building official, the exhaust from any hood serving
commercial food heat -processing equipment may terminate in a properly engineered
air recovery system for recirculation to the room in which the hood is located.
0) Fuel -burning Appliances. When vented fuel -burning appliances are
located in the same room or space as the hood, the vent shall be arranged to
prevent the hood system from interfering with normal operation of the appliance
vent.
Hood
Sec. 2003. (a) Where Required. Hoods shall be installed at or above all
commercial -type deep fat fryers, broilers, fry grills, steam -jacketed kettles, hot -
top ranges, ovens, barbecues, rotisseries, dishwashing machines and similar
equipment which produce comparable amounts of steam, smoke, grease or heat
in a food -processing establishment. FDr the purpose of this section a food -
processing establishment shall include any building or portion thereof used for
the processing of food but shall not include a dwelling unit.
(b) Materials and Installation. Types I and II hoods shall be constructed of
galvanized steel, stainless steel, copper or other material approved by building
official for the use intended.
Type I hoods constructed of galvanized steel shall not be less than 0.030-inch
(No. 22 gage) steel.
1jpe H hoods shall be constructed of not less than 0.024-inch (No. 24 gage)
steel.
All hoods constructed of copper shall be of copper sheets weighing not less than
24 ounces per square foot. All hoods constructed of stainless steel shall have a
minimum thickness of not less than 0.030 inch.
Every hood shall be securely fastened in place by noncombustible supports.
Every joint and seam shall be substantially tight. Solder shall not be used
except for sealing a joint or seam.
(c) Cleaning and Grease Gutters. Every hood shall be so designed when
installed to provide for thorough cleaning of the entire hood. When grease gutters
are provided, they shall drain to a collecting receptacle. fabricated, designed and
installed to be accessible for cleaning.
(d) Clearances for Type I Hood. Every portion of a Type I hood shall have
clearance from combustible construction of not less than 18 inches. This clear-
135
1 - !.r
2003 UNIFORM MECHANICAL CODE
I 1982 EDITION 2003
ante may be reduced to not less than 3 inches, provided the combustible material
I shall be in accordance with the requirements for low -temperature appliance
is protected with materials as specified for one -hour fire -resistive construction on
hoods.
the hood side. Hoods less than 12 inches from the ceiling or wall shall be flashed
solidly with materials of thickness specified in Section 2003 (b) or materials
1. Type I hoods for use over charcoal- and grease -burning charbroilers shall be
conforming to one -hour fire -resistive construction.
provided with separate exhaust systems. Undefined cooking equipment other than
Type I hoods or portions thereof penetrating a ceiling, wall or furred space shall
charcoal- and grease -burning charbroilers may be installed under a common
comply with all the requirements of Section 2002 (d).
hood. The minimum airflow for charcoal- and grease -burning charbroilers and
(e) Grease Filters. Type I hoods shall be equipped with approved grease filters
undefined equipment shall be:
or grease extractors designed for the specific purpose. All grease collecting
Number of Exposed Sides Formula
equipment shall be accessible for cleaning. The height of the lowest edge of a
4 (island or central hood) Q = 300A
grease filter located above the cooking surface shall be not less than that set forth
3 or less Q = 200A
in Table No. 20-A.
Alternate formula Q = 100PD
Filters and grease extractors shall be of such size, type and arrangement as will
2. Type I hoods when the cooking equipment includes high -temperature
permit the required quantity of air to pass through such units at rates not exceeding
appliances such as deep fat fryers:
those for which the filter or unit was designed or approved. Filter units shall be
Number of Exposed Sides Formula
installed in frames or holders with handles by which they may be readily removed
4 (island or central hood) Q = 150A
without the use of tools, unless designed and installed to be cleaned in place and
3 or less Q = IOOA
the system is equipped for such cleaning in place. They shall be sized and made
Alternate formula Q = IOOPD
removable so they may be passed through a dishwashing machine or cleaned in a
pot sink and so arranged in place or so provided with drip intercepting devices as
3. Type I hoods where the cooking equipment includes medium -temperature
to avoid grease or other condensate from dripping into food or on food preparation
appliances such as rotisseries, grills and ranges.
surfaces.
Number of Exposed Sides Formula
Filters shall be installed at an angle not less than 45 degrees from the horizontal
4 (island or central hood) Q = 100A
and shall be equipped with a drip tray beneath the lower edge of the filters.
3 or less Q = 75A
(f) Canopy Size and Location. For canopy -type commercial cooking hoods
Alternate formula Q = 50PD
the inside edge thereof shall overhang or extend a horizontal distance of not less
4. Type I hoods where the cooking equipment includes low -temperature
than 6 inches beyond the edge of the cooking surface on all open sides and the
appliances such as medium -to -low -temperature ranges, roasters, roasting ovens,
vertical distance between the lip of the hood and the cooking surface shall be not
pastry ovens and equipment approved for use under a Type II hood, such as pizza
more than 4 feet.
ovens.
EXCEPTION: Listed grease extractors are to be installed in accordance with the
Number of Exposed Sides Formula
terms of their listing and manufacturer's instructions.
4 (island or central hood) Q = 75A
3 or less Q = 50A
(g) Capacity of Hoods. For canopy -type commercial cooking hoods the
Alternate formula Q = 50PD
ventilation system shall exhaust through the hood a minimum quantity of air
EXCEPTION: Listed grease extractors are to be installed in accordance with the
determined by application of the following formulas:
terms of their listing and the manufacturer's installation instructions.
WHERE:
(h) Capacity for Noncanopy Hoods. In addition to all other requirements for
A = The horizontal surface area of the hood, in square feet.
hoods specified in this section, the volume of air exhausting through a noncanopy-
P = That part of the perimeter of the hood that is open, in feet.
type hood to the duct system shall be not less than 300 cubic feet per minute per
D =Distance in feet between the lower lip of the hood and the cooking
lineal foot of cooking equipment. Listed grease extractors, filters and collector
surface.
hoods shall be sized and installed in accordance with the terms of their listing and
Q =Quantity of air, in cfm.
the manufacturer's instructions.
When cooking equipment is installed back to back and is covered by a common
(i) Makeup Air. Each room provided with an exhaust system shall have air
supplied to the room equal to the amount of air to be exhausted. Makeup diffusers
island -type hood, the airflow required may be calculated using the formula for
shall be located to prevent a short-circuiting of air furnished to the exhaust system.
three sides exposed. When all appliances are electric, the airflow required may be
Windows shall not be used for the purpose of providing makeup air. The exhaust
reduced to 80 percent of the formula value. Type II hood airflow requirements
and makeup air systems shall be connected by an electrical interlocking switch.
136
137