Is 100% Tie Off Enough?

By: Greg Small, P.Eng

I cringe when I hear people stating and even bragging they always are tied off …. implying that they think they are safe , merely because they tie-off. This is like thinking that it is impossible to die in a car accident because you have your seat belt on. We all know that there is much more to staying alive in cars than just wearing your seat belts.

A prime example is residential roofing, an industry struggling to protect its workers now that US OSHA is finally forcing the issue, but does not yet have effective solutions that don't substantially increase cost. Unfortunately, some people think that installing a few inexpensive anchors near the peak of the roof and connecting workers to them with an adjustable lifeline system is safe (and in compliance). While there are double restraint techniques (tying off to two anchors at once) that can keep a worker 100% protected from falling, my exploration of this option, including paying a contractor an extra to try it out, showed that single line fall arrest or single and double travel restraint is NOT feasible for residential roofing unless we start building our houses with circular roofs. If done properly using roof anchors and adjustable lifelines, it slows the work down so much that scaffolding around the roof perimeter, or hiring a crane to serve as an overhead anchor, would be less expensive.


Roofers need to be able to walk the entire roof surface, often dozens of times at the edge where materials are arriving and leaving the roof. Their hands are full and unable to constantly adjust their lifeline lengths to minimize their fall risk. I occasionally come across roofers who are indeed 100% tied off (a good start) but generally leave themselves enough rope to move around. which is unfortunately also allows them to fall off and reach or swing into the ground.

Perhaps people think that automatic devices such as SRLS that keep the line length to the minimum are a solution. how many people realize that the ones with clutches (or external energy absorbers) need 15 feet of clearance for a 310 lb worker falling from a standing position? This is too much for a single story roof. SRLs without clutches or energy absorbers will stop the fall sooner, but give extremely high impacts (they only pass a 2 foot free fall to meet our standards). Big impacts risk injury to the worker, cutting of the line, and even failure of the roof anchor. On higher roofs, SRLs allow the worker to walk to and fall off a corner and swing into lateral obstructions or if the swing is large enough, into the ground.

Yes there are definitely situations where 100% tie-off is feasible and in compliance. However,much greater planning is required beyond simply being tied off. Our industry must evolve our thinking from 100% tie-off to effective fall protection systems.

Reluctance to be 100% tied off comes from both the need for freedom to move to get the work done (as mentioned by others on this post) but also from workers who might actually realize the futility of being tied off to a system that will not stop them from impacting the next lower level. I reluctantly agree that sometimes it may be less dangerous to work without fall protection than to work with ineffective fall  protection. You are more careful, and don't have the extra encumbrances and tripping hazards that a lifeline system may sometimes present.

The most misleading rule is "100% tie off above six feet", unless we have told the workers that a six foot lanyard won't work in this situation.

Don't get me wrong, I believe in 100% fall protection, and I have not done my job as a consultant and engineer in this field until I have achieved this. Stopping at 100% tie-off, however, and blindly trusting that this is all we need is NOT where any of us should stop. Stop looking for 100% tie-off and focus on workers using effective systems.


Don't be a Desperado

By: William R. Parsons, P.Eng

When I was a pilot many years ago, there was a newsletter we'd get that said "Learn from the mistakes of others, you'll never live long enough to make them all yourself".

We have this client. They're decent folks who asked us to do an inspection of the fall protection anchorage system on their roof. It's a 6 in 12 slope roof with asphalt shingles, like a house. As is often the case, they were keen to have the work done, and we were feeling that pressure. However, it was winter, so it was cold and there was snow and ice around. So I agreed to go there and do the inspection on a bright, sunny, cold and windy day.

My colleague and I strapped the ladder down on the truck, grabbed our PPE and drove 2 hours to get there. As soon as we pulled up, my gut told me there was no way. What would we do? Set the ladder, and go for it? Or go with my gut and try another day? That's when Desperado came to town. You see, Desperado is that little voice that reminds me that we'd lose the day, have to drive it all again (4 hours round trip) the next time, and that the asphalt is good traction, right? So just brush off the snow and make the client happy! Desperado is that part of you that shouts louder than your gut and tells you the risk is worth it.

I climbed onto the roof, and the ice that was loosened off the shingles became like ball bearings under my feet. As I perched there in the ice and snow and wind, being an engineer, I debated with myself about the energy absorbing properties of the snow bank I'd land in after the 10 foot fall. And then I debated the benefits of jumping so at least my trajectory would be 'controlled'. As it was, I moved very carefully and slowly back onto the ladder, and was never so glad to be there - bullet dodged.

Any time we listen to Desperado: climbing in the ice and snow, just reading that one text while driving, whatever… it raises the chance something bad will happen. It's because we allow too much interference into the task at hand. And once you go over that line, it can be very tough to get back.

So be safe out there folks, and go with your gut… don't be a Desperado.