Trust is a powerful word, and an excellent place to begin any discussion involving permanent roof anchors. Merriam-Webster’s noun definition is: one in which confidence is placed. The transitive verb definition is: to place confidence in: rely on: to hope or expect confidently.
The question arises, “Can the thing (roof anchor) do the thing you desire it to do, when you need it to do so?” Well, who really knows? There are only three possible answers: Yes. No. Maybe. Regardless of the truth, the roofer/maintenance person will make their own subjective decision prior to each service call. Let’s examine the possibilities.
This is the most dangerous answer, and the owner of a large roofing company that services the middle eastern US told me (after ordering some of our V-5 permanent anchors for his roof job at a University in NC) that he “forbids” his employees from using anchors installed by others. He cannot trust the installer did the job properly or that the manufacturer of the anchor did their work well either. The consequence of trusting an anchor (without being able to perform a proper inspection) may be tragic.
This inconvenient answer is the safest but requires the most work and/or training. This requires that every time work is performed on the roof, that the worker possesses the skills, tools, and training to choose good anchor points, install a temporary anchor on the roof, and then remove the anchor and repair the roof (if necessary) where the anchor was installed once the work is done. Not only is this time consuming, but it can also be a lot of work. Unfortunately, what usually happens is the worker takes an unnecessary risk by choosing not to use an anchor (oftentimes because they do not want to put holes in the roof) or they install a temporary anchor improperly with the wrong fasteners, insufficient in quantity or quality, and miss the roof rafter as well. The consequences of improperly installing temporary anchors may lead to a false sense of security, a fall, an injury, death, and hundreds of thousands of dollars in government regulation fees, insurance claims and lawsuit costs. * Metal roofs are even more challenging and dangerous. Safe access and anchor points for metal roofs will be discussed in more detail in a separate article.
Star Wars hero, Yoda wisely said, “Do or do not. There is no try.” Maybe is an unacceptable final answer. As they say in safety and the food industry, “When in doubt, throw it out.” “Maybe”, however, is how every anchor should be approached in the field prior to using it. Then, the potential user should inspect and verify that the anchor and fasteners are suitable for the task. If not, then do not use it. This brings up the subject of inspections.
Common sense tells the user to inspect the anchor prior to EVERY use, and OSHA also requires regular periodic inspections for permanent anchors and some localities require periodic load tests as well. Even so, the user still must decide at the exact moment prior to use, is the anchor capable of doing the job that it must perform? Whether an inspection was 2 weeks or 11 months ago, what’s changed since then? Is it still safe?
Let’s talk about what there is to inspect. Many “permanent” anchors have multiple parts with cables and connectors or rely on welds which may be inconsistent or low quality. Every part must pass the inspection and how do you access all these different parts safely? Do you have to climb on the roof just to inspect the parts? How time consuming is the inspection process? Does a separate 3rd party have to perform the inspection and how much does that cost? Actual load testing is probably the best way to “inspect” all the parts and verify the system will perform up to standards. However, this can be challenging and costly to perform on pitched roof surfaces, and then the question arises, “Did the load test just performed weaken the system?” Simply put, more parts equals more potential failing parts as well as more parts to inspect. We recommend choosing the simplest anchor system (with the fewest parts) that will perform the task required.
Material choice and manufacturing.
Generally, the permanent anchors available are either aluminum, carbon steel or stainless steel. Each of these materials comes in different grades which determine their durability, strength, flexibility, hardness, and finish capabilities. Oftentimes parts are machined and welded. The right questions to ask when selecting the material and manufacturing are: What are the loading requirements for the job? What environment will the anchor be exposed to regularly (normal humidity, saltwater, acidic atmosphere …)? Which material is best suited to last in that environment? Is there an anchor available without welds or bends? An entire library could be devoted to welding. Weld quality is limited by the welder, welding environment, and weld filler material. Welding and preforming create additional localized material stresses. If you can choose an anchor that does not have welds or bends, then you have eliminated two more potential failures and things that need to be inspected. If your anchor is inexpensive, expect inexpensive welds and the logical consequences. Paint, metal plating and galvanization may hide defects in manufacturing.
The choices are painted, plated, galvanized or no finish whatsoever. Once again, what environment will be “home” for the permanent anchor? Will it rust? Will the user’s fall protection connectors wear off the paint, plating or galvanized finish over time during use? What finish is easiest and will last permanently? Although the initial cost is higher, stainless steel requires no finish, is the most easily inspected, and is the most logical long term solution.
This is the most important consideration. What exactly is connecting the anchor to the roof structure? Many “permanent” anchors use nails or screws through the roof sheathing and into the roof rafter. The user has no method of inspecting/verifying that the fasteners are correct, and no way of determining if they are still in optimal working condition if they are buried in a roof rafter, hidden beneath the roofing material. We’ve witnessed roofers installing anchors with drywall screws and roofing nails. They usually use whatever fastener is available in their tool belt. However, let’s assume they used a new fastener that meets the manufacturer’s specifications. Have they weakened, sheared off or corroded just below the surface? Is the wood rafter sound in that location? The user cannot verify the condition of a fastener that is completely imbedded into a rafter without removing the fastener entirely. And, if that’s done and then the fastener is put back in the same location, the holding power has been compromised. Fasteners MUST be completely inspectable and/or replaceable for the permanent anchor to be trustworthy.
Any flashing system that fails, creates leaks and/or reasons for additional roof maintenance should be avoided. Is the flashing system reliant on caulk? Is it plastic, rubber, or some other material that deteriorates over time when exposed to the sun? Whatever flashing system is used, its life should be longer than the expected life of the current roof. All roofs eventually leak. However, it is especially critical that they not leak around a structural and safety point, such as a permanent anchor. Leaks in these areas could jeopardize the safety of anyone using the permanent anchor.
Can you use an anchor that’s been deformed? Generally, the answer is no. Unless the manufacturer specifies otherwise, if an anchor has been deformed in some manner, it should be removed from service. There are several inexpensive “permanent” roof anchors on the market that are thin galvanized steel and extend about 8 inches above the roof and generally come with a rubber or plastic cover. They are sometimes referred to by safety professionals as “one and done” anchors. They cannot be effectively used for positioning because they will bend. Oftentimes, they also are secured to the rafter with nails buried into the side of the rafter (not inspectable). Having an anchor that only “works” during a fall, is like having a phone that cannot dial out and only takes an incoming call once. Anchors should also be capable of helping the roofer reach, suspend from, pull on and do their work safely.
Does the anchor blend naturally into the roof or does it detract from the building’s aesthetics? Safety is a high priority, but most owners of attractive or historic buildings do not want a long metal pipe protruding through their roof every 30 feet with a cable strung between them. That’s like framing the Mona Lisa with a white plastic frame from Walmart. It’s a frame, but not the best choice for that piece of art. This type of permanent anchor system is well suited for flat commercial roofs, but not for pitched or beautiful or historic roofs.
What happens to the rafter when the anchor is under an extreme load? Rarely, does any rafter or truss become stronger over time. Attics can often be hot, humid environments. Stress cracks occur and wood has knots. Are all the fasteners in one small location? Is there a knot of stress crack or rot at that location? Does the anchor pinch the rafter while under load to create additional stress at that location? When there is a failure, will it occur slowly and be noticeable with inspections or will it be immediate and catastrophic? Basically, it comes down to this: If you are going to trust an anchor point (unless you use multiple anchor points), you are putting all your eggs in one basket. Make sure that basket is in excellent condition prior to carrying the eggs. The best anchors will distribute the load over a longer section of the rafter.
Most permanent roof anchors are designed to be loaded in the direction parallel to the roof rafter. Most people fall downwards right? Gravity sends people from the top of a roof towards the bottom of the roof (along the rafter direction). OSHA requires that the anchor be capable of supporting a 5,000 pound load per person attached to the anchor. However, many roofs cannot handle a 5,000 pound load and 2 x 4 roof trusses cannot unless they were engineered and reinforced at the specific anchor point location in some way to distribute the load as well as keeping the wood from crushing.
Granted, there is some safety margin built into OSHA’s 5,000 load requirement, and workers utilize load limiting lanyards to limit the loads to between 900 and 1800 pounds (if they keep their free fall distance short enough). So, everything should be fine and you don’t need to consider unplanned loads right? I wish it were that easy. Do a surprise visit on a few roofing job sites and you will find: 80% working without fall protection (usually just wearing a harness without anything attached to it or a rope with enough slack to fall into the object below) and out of the 20% remaining you will find multiple people connected to the same anchor point, people working above their anchor point, and most of the anchors not installed according to the manufacturer’s specifications and oftentimes the workers are in such a position that a fall will side load the anchor in which they are connected. So, select the anchor that will give the worker the best chance of surviving the unplanned.
People come and go from every business. People move on. Company names remain. Companies outsource and shop manufacturers for lowest prices. Companies are bought and sold. Companies must be profitable and sometimes it seems they let competition get in the way of common sense. Many “copy cat” companies sell their version of anchor A because another company sells anchor A, and they do so without ever actually knowing or investigating if anchor A was a smart design to begin with. After enough copies of anchor A are being replicated, the consumer also sees anchor A as normal and forgets to question the anchor or the company. Besides, who likes to spend time thinking about roof anchors? Right?
The diagram at the top shows what a quick internet search will reveal for permanent roof anchors. Over the last decade, I have used or installed several of these types and was thankful to have them at the time. Each of them can work satisfactorily for a short duration (especially if the user maintains a tight rope and is aware of each anchor’s limitations. A basic understanding of wood, roof framing, roofing and engineering aid in seeing the obvious design and/or installation flaws. Study the diagram and you will begin to see the design flaws appear. Use these anchors with caution, especially if you cannot inspect the fasteners prior to each use.
An engineer once told me after solving the most fun and difficult puzzle I’d ever tried. I asked him, “How did you do it so quickly? Most people give up in frustration and that’s why I enjoy giving it to them. You solved it in 3 minutes. How?” He said, “Once I removed the possibilities of what doesn’t work, what cannot work, all that remained is what can work. And then, I solved it.” It is this principle that we applied to develop Slator-USA’s, V-5 permanent roof anchor. The diagram above will show you some of the problems we eliminated. Once eliminated, the solution became clear.
Please don't hesitate to contact us about any roof anchor questions. We are happy to help everyone work more safely on roofs.