Standard Interpretations - Table of Contents Standard Interpretations - Table of Contents
• Standard Number: 1926.502(f)(1); 1926.502(f)(4); 1926.502(h)(2)

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at

October 17, 2000

Mr. Kenneth Brown
10255 W. Higgins Road
Suite 600
Rosemont, IL 60018-5607

Dear Mr. Brown:

This is in response to the April 4, 2000, package and letter you forwarded from Janet Flury to the Occupational Safety and Health Administration (OSHA). You ask us to determine which of the 44 pictures of roofing equipment you submitted are mechanical equipment as defined by 29 CFR 1926, Subpart M, the fall protection standard for construction.


Question 1: What is the significance of determining which pieces of equipment are mechanical equipment?

Answer: 29 CFR 1926.502 prohibits the use of mechanical equipment during roofing activities on low sloped roofs where only a safety monitor is used or outside of an established warning line. Where it is permitted, fall protection must be used.

Question 2: What is mechanical equipment?

Answer: In §1926.500, the standard defines mechanical equipment as "all motor or human propelled wheeled equipment used for roofing work, except wheelbarrows and mopcarts."

In the preamble to the Guarding of Low-Pitched-Roof Perimeters During the Performance of Built-Up Roofing Work, (Federal Register Vol. 45, No. 222, page 75,623), OSHA explained that wheelbarrows and mopcarts were excluded from the definition because:
"...their use does not require employees to move backward. In addition, they are light in weight and therefore develop little momentum. Wheelbarrows and mopcarts do not present the same degree of risk to roofing employees as do such machines as felt layers and gravel buggies. (Cf. Ex. 2:36, 120, 152). Mopcarts and wheelbarrows do not require employees to divide their attention between the equipment they are using and the roof edge, as they would have to do with heavier, more awkward machinery."
Question 3: What are the hazards associated with operating mechanical equipment while doing roofing work?

Answer: The preamble also explains (Vol. 45, No. 222, page 75,622) that when operating mechanical equipment near the edge of structure:
"...the greatest hazards with mechanical equipment operation are at the points of turn-around (perpendicular to the direction of equipment movement) where an employee's attention is no longer on the edge [fall] hazard, but rather is on the effort required to turn the equipment around (cf. Ex. 2:82, 120, 191). At these points, employees are in danger of losing their balance because of the sometimes awkward motions necessary to turn the mechanical equipment, and because of the need to step backward toward the edge, as they try to line the machine up for the next run."
Question 4: What OSHA regulations address the use of mechanical equipment during roofing work in construction?

Answer: Roofers are allowed to use mechanical equipment without fall protection only under specified conditions, which are addressed in §1926.502. Mechanical equipment is mentioned in respect to the use of warning line systems and safety monitoring systems in sections 1926.502(f)(1)(i), 1926.502(f)(1)(ii), 1926.502(f)(4) and 1926.502(h)(2). These requirements are:

When mechanical equipment is not being used, the warning line shall be erected not less than 6 feet (1.8 m) from the roof edge.
When mechanical equipment is being used, the warning line shall be erected not less than 6 feet (1.8 m) from the roof edge which is parallel to the direction of mechanical equipment operation, and not less than 10 feet (3.1 m) from the roof edge which is perpendicular to the direction of mechanical equipment operation.
Mechanical equipment on roofs shall be used or stored only in areas where employees are protected by a warning line system, guardrail system, or personal fall arrest system.
Mechanical equipment shall not be used or stored in areas where safety monitoring systems are being used to monitor employees engaged in roofing operations on low sloped roofs.
On May 19, 1998, OSHA issued an interpretation memorandum (Wiehrdt memo, attached) that allows a portion of a piece of mechanical equipment (the hose and roller/wand) to be used outside of a warning line and in areas with only a monitor present. Using the hose and roller is not considered any different from using a broom or mop to spread glue in areas protected by a monitor, which is allowed by the standard. However, the wheeled, pressurized storage tanks of the machine were considered to present the same hazard as mechanical equipment for the following reasons:

  1. it has to be wheeled and maneuvered into position;
  2. its gauges are monitored; and
  3. it is more cumbersome to handle than a wheelbarrow or mop cart due to its load and size.

All of the reasons listed above could distract the operator long enough to step back and off the edge of the structure while operating the equipment.

The answer to your question

Question 5: Attached is a list of 44 pieces of equipment. Are any of them considered "mechanical equipment" under these standards?

Answer: Any piece of equipment that fits the definition of mechanical equipment and is not a wheelbarrow or a mop cart is, by the terms of the standard, prohibited outside of a warning line and in areas where only a monitor is used. However, the worker is allowed to operate the mechanical equipment in these areas with fall protection in place.

We have attached a list of how we would classify the 44 pictured items that you submitted. Most of them are not considered mechanical equipment. These do not fit the definition of "mechanical equipment" primarily because they are not wheeled, propelled by a person, or motor driven. Equipment such as power tools, brooms, axes, pumps, and hand tools do not fit the definition.

Some of the equipment does fit the definition, but have hoses and/or attachments that allow the wheeled portion of the equipment to remain inside the warning line while the employees can use the hoses and/or attachments to do their work outside of the line. Like the equipment discussed in the Wierhdt memo, this equipment does not have to be maneuvered into position anywhere near the edge of the walking/working surface in order to use the attachments. These types of equipment include but are not limited to compressors, pressure pumps (sprayers), vacuums, and glue dispensers.

Finally, some of the equipment fits the definition and does not have hoses/attachments like the equipment above. These pieces of equipment, therefore, are prohibited from being used outside of warning lines and where only safety monitors are used. These types of equipment require the worker to guide the machine to perform various tasks on the roofing material, such as cutting, sanding, applying finishes and glues, scraping, compressing or removing roofing materials. They may also require the worker to operate levers and switches or monitor gauges while maneuvering the machine to perform the tasks mentioned above. The worker's concentration is divided between the fall hazard and operating the equipment while moving around near the edge of the working/walking surface.

A categorized list of the equipment you submitted is enclosed with this response. We have indicated where we would need more information about the operation of particular pieces of equipment to give guidance on how they would be categorized.

If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Russell B. Swanson, Director
Directorate of Construction

[Corrected 6/2/2005]


Equipment that is not mechanical equipment as defined in Subpart M.

1. 3/4 HP Air Compressor (not on wheels)
2. Wheel Barrow
3. Puddle Pumps
4. Porter Cable Reciprocation Saw
5. Dewalt 1/2 Impact
6. Liester Gun
7. Electric Deck Saw
8. Metabo Hammer
9. Milwaukee Screw Gun
10. Black and Decker Screw Gun
11. Hilti Screw Gun
12. Metabo Cordless
13. Push Lugger
14. Makita cordless
15. Hilti Hammer
16. AEG Hammer
17. Skill Worm Drive
18. Mop Cart
19. Bosch Hammer
20. Deck Saw
21. 36" Broom
22. Axe
23. Nail Gun
24. Framing Nail Gun
25. Garlock Hydraulic Roof Hoist
26. Makita Heat Gun

Equipment that meets the definition of mechanical equipment but components (hoses and/or attachments) of the equipment may be used outside of the warning line.

1. Power Washer (hose outside)
2. Power Roller Glue Machine (roller attachment outside)

Equipment that meets the definition of mechanical equipment and is prohibited outside of a warning line or where safety monitors are used on a low sloped roof.

1. Garlock Cutter
2. Spud machine
3. Four Wheel Cart
4. Hot Dispenser
5. Felt Machine
6. Hand Rhino
7. Roof Blower
8. Roof Vacuum
9. Snow Blower

Equipment that meets the definition of mechanical equipment but more information about how it functions and is used in roofing operations is needed.

1. Saramatic
2. 110 Gal Lugger
3. Draggin Wagon
4. Accutrac
5. Primer Pump
6. SFS Machine

No information submitted on the product.

1. Push cart

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