Ladder Safety with Sean White

Falls are one of the most common hazards on a job site, and ladders are often part of that risk, especially on residential solar installs where you’re going up onto a pitched roof. A few specific practices can go a long way toward staying safe: choosing the right ladder when there’s a risk of shock, extending it far enough above the roofline, and setting it at the right angle.

We sat down with Sean White, a lead instructor for HeatSpring’s PV Associate (PVA) and O&M Associate Technician (OMAT) courses, for two short clips covering these practices.

Want to build a deeper foundation in solar safety, along with the rest of the PVA and OMAT curriculum? You can sign up for the PVA course or the OMAT course to get started.

Solar Ladder Safety – Fiberglass vs. Aluminum

The 4:1 Ladder Ratio

Transcripts below.

One of the things you’ll run into when you’re doing operation and maintenance (O&M) is ladder safety. You’re going to be climbing a ladder — so what do you do? You don’t want the ladder to become part of the circuit. So what kind of ladder do you use if you’re going to be exposed to energized electrical equipment?

Now, you might have guys on a job who are just carrying modules up onto a roof, and I’ve never heard of anybody getting shocked or electrocuted from a single module. And by the way, what’s the difference between a shock and an electrocution? With an electrocution, you don’t survive. With a shock, you may or may not survive. An electrocution is a shock that kills you — sorry to get so dark, let’s get back to that fusion reactor in the sky.

That fusion reactor is sending electricity down to 10 modules in series. You get 10 times the voltage, and you don’t want to complete that circuit with your body. A ladder can carry electricity if it’s aluminum, so typically what they say is: use a fiberglass ladder.

But here’s something to know about fiberglass ladders — every fiberglass ladder I’ve ever seen still has aluminum rungs on it. Those rungs are the steps on the ladder, and they’re about 12 inches apart. You should know that too.

And while we’re talking about ladders: you put your ladder up so it extends three feet above the top edge of the roof when you lean it against the roof. Three feet is three steps, since each step is about a foot. Somebody could catch you out just by taking a picture — if they only count two steps, you’re going to jail. Safety jail. OSHA will lock you up for life. So make sure you’ve got those three steps showing.

So, for energized electrical equipment: use a fiberglass ladder, which usually has aluminum steps.

The 4:1 Ladder Ratio

There’s one more ladder topic I want to cover, and that’s the angle you position the ladder at. Typically when we’re talking about a ladder, we’re talking about residential solar work — going up onto a roof. We’ve already covered that the ladder needs to extend three feet above the edge of the roof, and that you want a fiberglass ladder if there’s a risk of shock. The next question is positioning: what angle do you put that ladder at?

A lot of people will say a 4:1 ratio, or a 1:4 ratio — those are basically the same thing, just depending on which way you’re looking at it. But what is that ratio actually measuring? If you’re leaning a ladder against a roof, people usually describe it as one foot of run for every four feet of rise. And you could express that ratio in any unit — feet, inches, miles, even light years, though nobody has a ladder that long.

Here’s the part that’s actually a little surprising: that ratio isn’t rise — it’s the length of the ladder. I always learned it as rise, the same way we talk about a roof’s slope as rise over run — 4 and 12, for example, meaning 4 up and 12 out. But a student in one of my classes, after I’d been teaching this for about 19 years, told me to go read the OSHA language word for word. So I looked up OSHA 29 CFR 1926.1053(b)(5)(i), and it says non-self-supporting ladders need to be positioned so that the horizontal distance from the top support to the base is one-quarter of the working length of the ladder — the ladder’s length, not its height.

If you work out the trigonometry, the difference between using length versus height is only about half a degree — small enough that nobody would notice in practice, since the vertical distance is so much greater than the horizontal one. But if you want to be exact: it’s one foot out for every four feet of ladder length, not four feet of height. That’s the actual 1:4 ratio.