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Launch Slideshow

Temporary Bracing for Roof Trusses

Temporary Bracing for Roof Trusses

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    Workers framing roofs with trusses have been injured and killed by the domino-like collapse that can occur when one truss leans against the next and the whole set topples. To prevent this from happening, the author’s crew has already set up a series of vertical supports and an array of diagonal braces that run back to the ground at the gable end.
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    The gable truss is nailed to these braces as soon as it’s set.
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    Precut 1x2 spacers 24 inches long are nailed between trusses as each truss is set.
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    Temporary structural bracing is nailed across the top chords of the trusses.

Controlled Access Zone

The CAZ — as it’s usually called — is especially important on a job like this. We mark the area with caution tape and put up “Keep Out” signs. This keeps random people from being exposed to the hazard of the trusses swinging overhead or to the risk that the whole set of trusses could topple before they’re braced. We don’t want curious homeowners wandering into the danger zone to see what’s going on, or subs moving around on their own business. We keep everyone out who’s not involved in the work.

The “competent person” (Frank) is responsible for controlling access to the zone; nobody can enter the CAZ without his permission. Furthermore, nobody can enter it without being briefed by either me or Frank on his specific job inside that zone, and on the special risks present there. Also, anyone entering the CAZ has to be equipped with a hard hat and any other protective gear needed for the work.

The caution tape and signs also help to keep the crew alert and focused on getting the job done efficiently and safely. That’s the whole point of alternative procedures: Since you aren’t protected by a passive measure like a railing or harness, you have to use active measures that emphasize alertness, attention, and understanding of the process.

Workers framing roofs with trusses have been injured and killed by the domino-like collapse that can occur when one truss leans against the next and the whole set topples. To prevent this from happening, the author’s crew has already set up a series of vertical supports and an array of diagonal braces that run back to the ground at the gable end (A). The gable truss is nailed to these braces as soon as it’s set (B). Precut 1x2 spacers 24 inches long are nailed between trusses as each truss is set (C), then temporary structural bracing is nailed across the top chords (D).

Restricted Duties

Part of my function as owner and safety officer is to figure out each day which crew member should be placed where. And then, as I mentioned earlier, each person is briefed on his particular role. On this day, I placed John Muncy on the ground, outside the walls. John is actually my painter, so I don’t need him swinging a hammer. But he pays attention to detail, so his job was to hitch the trusses to the spreader bar, man the control rope, and work signals with the crane operator.

(As this article was going to press, OSHA released a new rule that requires training and testing for the “signal person” and “qualified rigger” in crane operations. Although my crew members appear to be in compliance, I may need to update my procedures — by giving everyone a written quiz to document their understanding of crane procedures, for instance.)

I put brothers Rick and Roger Conlon at the two outside walls, working the ends of the trusses from the OSHA-compliant staging. It’s helpful to have a guy at each end; I’ve seen projects where a single carpenter has to deal with both wall plates, and it’s slow and tiring as well as dangerous for one person to have to continually climb up and down and run back and forth. With two men, each has a stable platform to work from and neither has to do a lot of climbing up and down.

I placed Carlos Saraiva on the deck inside the walls, where he could cut and pre-nail spacers to go between the trusses and also supply everyone on the staging and trusses with spacers, bracing, nails, and anything else they might need. That way, nobody would have to climb up and down to fetch anything, which greatly reduced the risk of falling. Also, by keeping everyone supplied, Carlos helped keep the whole job flowing smoothly — and the crew definitely kept him busy.

I put Eric Dougherty at the center of the trusses on 6-foot-high rolling staging, installing spacers and bracing for that part of the trusses and feeding supplies to the carpenters at the peak — again, to reduce the risk to the guys up top.

At the peak, I stationed two of my best carpenters — foreman Frank, the “competent person,” and Peter LaTour. Peter is actually a qualified supervisor himself — I had brought him over from another job for that day’s framing, and if Frank had been out for some reason, Peter could have run the job.

It’s important to have highly skilled and responsible people working the peak. Those carpenters have to walk on the trusses before the complete bracing system is installed, and they need to know what they’re doing. Sometimes you’ll see only one person at the peak, but this is another place where I’m more comfortable with two. There’s much less climbing around and the trusses are stabilized sooner, reducing the time everyone is exposed to unbraced framing.

By making sure that everyone is assigned to a specific limited task, I make it easy for each person to focus on his own work and his own safety. If for some reason we need to switch a worker to a different task — for instance, if someone has to leave and we need a replacement — we brief that person on his new role before he begins.