The work:Service on a rooftop unit at an industrial plant.
The apprentice:Allen Charles Edwards (ACE) — first-year mechanic.
The technician:N. Arthur Thomas Egan (NATE) — 15-year HVACR veteran.

NATE and ACE are proceeding to a location that will require them to work on the roof. NATE needs to know what knowledge ACE has about ladders and ladder safety so he can provide the proper training.

NATE: Ace, while we’re driving to the site I’m going to ask you a series of questions about ladder safety because we have to set up the ladder to get on the roof. I hope you had some instruction at the technical school.

ACE: The school conducted a separate training day just on ladder safety. I even know that some of the regulations come from the Code of Federal Regulations Title 29, Subpart X — “Stairways and Ladders.”

NATE: Well, let’s see how much of the technical stuff you remember.

1. If there is a height difference of (fill in the blank), then a ladder shall be provided.

a. 9.5 inches
b. 19 inches
c. 28.5 inches
d. 38 inches

2. Which way do you face when ascending or descending the ladder?

a. It doesn’t matter.
b. Away from the ladder.
c. Facing the ladder.
d. The way it is easiest to carry materials up and down.

3. When setting an extension ladder, the horizontal distance from the top support of the ladder to the foot of the ladder should be approximately what distance?

a. 1/8 the working length of the ladder.
b. 1/4 the working length of the ladder.
c. 3/8 the working length of the ladder.
d. 1/2 the working length of the ladder.

4. How high above the upper landing area must the ladder extend?

a. 1 foot
b. 2 feet
c. 3 feet
d. 4 feet

5. What is the minimum grasping requirement for ascending and descending the ladder?

a. There is no requirement.
b. One hand.
c. Two hands.
d. Always with a safety strap.

NATE: Okay, Ace. Here’s the final question.

6. Are you allowed to carry loads up a ladder?

a. Yes, as long as it doesn’t cause you to lose balance or fall.
b. No, all loads must be raised to the working area independently.

Author’s Note
Please remember no question appearing in these articles is on a NATE exam. These questions and dialogue are my creation alone. The NATE Technical Committee does not review the article content, and the committee has the final decision for the use of a question on the tests.

Interpretation of codes, regulations, and standards comes from my experience as a technician and a contractor. Different jurisdictions have varying interpretations. The particular area a job is being done in will dictate which viewpoint is to be properly used.

I learn a lot from your commentary and try to incorporate information into the next article, so please continue to comment.

Patrick L. Murphy
Director of Technical Development

Answers: 1) b; 2) c; 3) b; 4) c; 5) b; 6) a.

Patrick Murphy is director of technical development, North American Technician Excellence (NATE). If you have any further questions or comments on this quiz, contact Murphy at

Publication date: 06/30/2003