Roof Anchors
Understanding a building’s roof anchor maintenance and inspection requirements is not difficult, and with relatively little effort, Property Managers can automate this process in 3 easy steps.
1. KNOW THE ANCHOR TYPES AND REQUIREMENTS
The building’s initial design drawings or the roof anchor plan will identify the type, attachment, and purpose of the roof anchors and fall arrest system. Not all fall arrest systems are designed for swing stage use.
There are various types of anchors and components that may form part of your fall arrest systems, such as Davit arms and horizontal lifelines, however, for the most part, we come across 2 types of anchor points:
Figure 1. Wall Mounted Anchors
Figure 2. Pedestal Anchors
The building’s anchor plan will identify whether you have adhesive, expansion, or mechanically fastened anchors. Typical examples of pedestal anchors are:
Figure 3. Adhesive anchor (note bolts embedded in the slab)
Figure 4. Mechanically fastened anchor (note bolts through the slab and fastened on the underside)
The Health and Safety Code for Suspended Equipment Operations stipulates that, at a minimum, all anchors must be inspected at intervals not exceeding 12 months. This annual, visual inspection requires the inspector to:
- Review the design drawings to ensure compliance with current regulations, standards, and engineering standards – Did the plan make sense?
- Assess the system to ensure compliance with the engineered drawings – Did they install the anchors according to the plan?
- Inspect all exposed, visible, and accessible components of the system for signs of distress – Are the anchors in good condition?
- Inspect all adhesive and expansion fasteners – Were the anchors requiring occasional load testing included in this inspection?
Mechanically fastened anchors are attached to the structure using welds or fastened bolts and typically require only the annual visual inspection.
Adhesive of expansion anchors, on the other hand, require physical load testing of at intervals not exceeding 5 years.
The idea behind this additional requirement for adhesive or expansion anchors are attached to the structure by adhesive (glue) or forces induced by expansion (friction, wedge pressure) and are more prone to non-visible methods of loosening or failure.
Anchors are required by code to meet two distinct standards.
- Anchors must resist 22.2 kN (5000 lbs) of force without failure.
- Anchors must resist 11.1 kN (2500 lbs) of force without permanent deflection.
Permanent deflection refers to any movement of the anchor that does not return to the pre-loaded condition when the load is removed.
As such, during load tests, anchors are loaded to 2500 lbs (50% of their design capacity) to confirm that they meet the second standard. When load tested in this way, anchors that have been properly designed and installed should not undergo any damage.
The 5-year load test requires more time on site for the inspection, wherein the inspector will bring appropriate equipment to load the anchors and measure any deflections. A typical loading setup is shown below:
Figure 5. Typical loading apparatus between pedestal anchors
2. KNOW WHO CAN INSPECT AND REPAIR THE ANCHORS
The standard mandates that either the visual inspection or the load tests be completed by a professional engineer, or a qualified person under the supervision of a professional engineer. There are several general building engineers and roof anchor inspection companies that can provide this service.
Following visual or loading inspections, the report may determine that minor repairs, such as caulking or flashing failures, or major repairs, such as anchor replacement, may be required. Depending on the level of complexity of these repairs they may require a simple handyman or the involvement of a design engineer.
If a Property Manager is unsure from whom to obtain an inspection or load test, they can seek recommendations from their general building engineer, their window cleaners, or their roof anchor manufacturers.
3. SCHEDULE YOUR INSPECTIONS.
Although roof anchors must be certified for any work that will require attachment (caulking replacement from swing stage, pre-cast panel inspection from bosun’s chair, etc.), typically the inspection is scheduled to be completed before the first window cleaning of the season. Recalling that varying degrees of repairs may be required following the inspection, we recommend that Property Managers look to schedule their annual inspection during the month of March or April.
Many anchor inspectors and certifiers are offering multi-year inspection programs, wherein the inspector is engaged to perform all inspections (annual visuals and load testing) with the requirement that they will be completed each year without explicit annual authorization. This approach reasonably shares the requirement of ensuring regular annual inspections with the contracted inspector and allows for cost savings as the inspector benefits from previous annual work they have performed.
Important things to remember:
- Building or anchor plans will indicate the types of anchors on the roof.
- All anchors must be visually inspected every year.
- Adhesive or expansion anchors need to be load tested every 5 years.
- Qualified inspectors under the supervision of a Professional Engineer may perform the inspections and load test.
- Annual scheduling or pre-contracting inspection services helps ensure that the fall arrest systems will always be compliant.