Board Policies and Guidelines (Sheet Metal Workers)

Regulatory Reminders

Board of Sheet Metal Workers CORI Policy

Objective: To provide instructions and requirements for commercial kitchen grease duct testing and inspection, to ensure that the system was installed liquid-tight and grease-tight in order to contain the spread of any grease duct fires, which risk the loss of life and property.

Summary: Currently, many installers and inspectors use the 100-watt light bulb test required by the International Mechanical Code (IMC) to help identify inferior welded seams. This test is not practical for testing field-welded grease ducts vertically installed in shafts where full visibility of all welded seams may not be available, or where a 100-watt light bulb cannot be pushed or pulled through a horizontal duct run.

Effective IMMEDIATELY, the Board advises that the entire grease duct system be leak tested under negative pressure equal to the duct fabrication pressure class. This test will measure and prove the tightness of the duct system without visibly inspecting each welded seam. Instructions on how the test should be performed follow below. State Sheet Metal Inspectors have found this to be effective in identifying leaks that may otherwise not have been visible with a light bulb test.

This test must be performed by a properly licensed sheet metal business or individual that specializes in Testing, Adjusting, and Air Balancing of HVAC systems.

Objective: To provide clear installation instructions and requirements for the installation of standard fire dampers and combination fire/smoke dampers, so that they are installed with adequate access, retaining angles, and clearances for expansion. Adherence to these requirements will allow for proper operation upon activation.

Summary: Ducts with fire dampers and/or combination fire/smoke dampers are often installed incorrectly. Some installers do not provide adequate room for expansion, and the clearance space is sometimes filled with mineral wool, ceramic fiber, or fire-stopping caulks, which is technically unnecessary, potentially detrimental to the installation, and could result in voiding the UL listing of the damper. Where ducts without fire dampers penetrate walls and floors, it is likewise common for the annular space around the duct to be sealed or fire-caulked, which should not be done with fire dampers or combination fire/smoke dampers. 

State Sheet Metal Inspectors have identified the following common incorrect damper installations: 

1) Dampers installed without retaining angles;

2) Dampers installed with retaining angles attached to the duct and sealed to the wall with fire caulk that may limit expansion;

3) Dampers installed without any room for expansion; and

4) Dampers installed with additional material added to the expansion space. 

In order to address these safety concerns, effectively IMMEDIATELY, all sheet metal licensees and inspectors should follow this advisory for the proper and safe installation of fire dampers and combination fire/smoke dampers. More specific instructions follow below.

Any flat seam, flat locked and/or soldered seam, standing seam, batten seam, horizontal seam, custom designed or prefabricated metal roofing and related components (flashing, trim, gutters, downspouts, conductor heads and scuppers) that are interconnected to the metal roofing system with mechanical fasteners or locks and seams and are installed on projects that are deemed non-residential per 271 CMR.

Excludes:

Residential buildings as defined in 271 CMR

Through wall flashing

Gravel stops

Coping

Soffits and fascia

Gutters and downspouts that are not interconnected and fastened to the metal roofing system

Residential Bathroom Exhaust Fans / Kitchen Exhaust Fans - Interpretation:

All residential fans and associated ductwork shall be installed by a licensed sheet metal worker.

New installations shall require a sheet metal permit and inspection.

The replacement of an existing residential fan shall be considered a minor alteration and will not require a sheet metal permit.

Exception:

The installation of combination fan/light units may be installed by a licensed electrician.

Effective Date: November 15, 2021

Purpose:

The Board of Examination of Sheet Metal Workers ("Board") issues this policy bulletin to clarify the role of preventative maintenance in sheet metal work and to describe when a sheet metal license is required for such work.

Authority:

Pursuant to M.G.L. c. 13, § 102, the Board is authorized to administer and enforce the law with respect to the practice of sheet metal work. “Sheet metal work” is defined by statute in M.G.L. c. 112, § 237 as: the manufacturing, fabrication, assembling, handling, erection, installation, dismantling, alteration and repairing of all commercial duct or air exhaust systems, except for refrigeration and combustion units; installation of commercial fans, sheaves, belt guards, dampers, louvers, screens, registers, grilles, diffusers, sound traps, attenuators, mixing boxes and access doors in connection with duct or air exhaust systems, commercial and industrial architectural sheet metal watershed roof systems, except for roof coverings and associated metal flashing; the testing, adjusting and air-balancing of all air-handling equipment and ductwork installed during new or remodeling construction, the installation of commercial and industrial kitchen hoods, kitchen vents, bathroom exhaust vents and fans… The Board further clarified in 271 CMR 2.00 that “[f]unction and purpose shall determine ‘sheet metal’ work, not the materials employed.”

Policy:

Preventative maintenance of sheet metal work with respect to commercial duct or air exhaust systems and parts may include visual inspections, cleaning, or oiling/greasing. This type of preventative maintenance work does not require a sheet metal license, or a sheet metal permit issued by the authority having jurisdiction.

However, the Board notes that any reinstallation, handling, dismantling, alteration or repair of previously installed sheet metal work that occurs during the course of preventative maintenance, as defined in M.G.L. c. 112, s. 237 and 271 CMR, would be considered sheet metal work that must be performed by licensed sheet metal workers with a sheet metal permit issued by the authority having jurisdiction.

An unlicensed worker or technician providing visual inspection, cleaning, or oiling and greasing who discovers during the course of preventative maintenance that sheet metal work is required to maintain the system must not perform sheet metal work. Those who perform sheet metal work without a license are subject to discipline from the Board pursuant to M.G.L. c. 112, §§ 65A and 237.

Authority: M.G.L. Chapter 112, Section 237; 271 CMR 2.00 et. seq.