At first glance, a roof anchor is a simple product comprised of a basic steel post with a u-bar attached to the top, but in actuality it is so much more than that, especially when installed after the completion of a structure.
We partnered with Tyler O’Leary, a senior estimator and AutoCad specialist at CSAI: Canadian Safety Anchor Inspections Inc., a leader in roof safety, to share the ins and outs of roof anchors and why they are important for the safety of your roof workers.
For the last 28+ years, CSAI has specialized in roof anchor design and placement to accommodate building restoration, fall arrest systems, and window cleaning services. They have worked on thousands of roofing projects and anchoring systems, including interior leg anchors to allow for emergency rappelling inside the CN Tower.
What Does A Roof Anchor Do?
Roof anchors are mechanisms built into the fabric of your structure that are used to secure personnel who are doing work on your roof. Roof anchors are used to restrain workers and prevent falls for any roofing work, from window washing to building restoration. Roof anchors are the easiest way to ensure the safety of workers on your roof because they are engineered permanent fixtures that workers can tie off to with their own safety equipment. By using this kind of anchor, your workers do not have to set up an external safety mechanism, saving you time and money.
Are Roof Anchors Necessary?
Safety mechanisms are required by law for almost all roofing work according to the Occupational Health and Safety Act and Regulation for Construction Projects.
“Barriers, warning signs or other safeguards that are used to protect workers must be used where vehicular or pedestrian traffic may endanger the safety of any worker, disturb the worker’s safety lines or support lines (for example, restricted public access to the support system area) [Regulation 859, section 13]. The equipment should be stored in a secured position when not in use.”
Having built-in mechanisms makes the process of ensuring safety for your workers streamlined and regulated, reducing accident risk.
Types of Buildings That Benefit From Roof Anchors
Any building that is higher than one story benefits from the installation of roof anchors. With almost no exceptions, all buildings will require some form of maintenance that is a fall risk to workers, whether on the roof or on suspended stages. Specifically, buildings that are window-heavy and require restoration and/or regular window cleaning benefit immensely from roof anchor systems.
Key Design Criteria And Considerations For Roof Anchors
When considering installation of roof anchors, there are several criteria that we consider before determining if roof anchors will work for the building in question.
Stage of Development
Installing roof anchors in new builds is much simpler than installing them on buildings that are being retrofitted.
In order for a retrofitted anchor to be installed successfully, the substrate must be sufficiently thick to carry the anchors otherwise the anchors would need to be bolted through the substrate with a steel plate on top and bottom for structural integrity. The different types of substrates, and associated anchor methods of installation, include, but are not limited to:
- Concrete – adhesive or through bolted type
- Hollow core slab – through bolted or cast in place hollow core type
- Steel structure – welded or wrapped steel “I” beam type
- Open web steel joists – wrapped joists with HSS plates on top and bottom type
- Hambro joists – thin concrete on metal pan – wrapped joists with HSS plates on top and bottom type
- Timber Reinforced – Wrap Timber and HSS Reinforced Timber Anchors
- Wall anchors – adhesive, through bolted, HSS reinforced wall type, welded or through bolted to “I” beam type
Depending on the use of the roof anchors (window cleaning, balcony restoration etc), different anchor types would be recommended (wall vs. roof anchors) in order to ensure the efficient use of the anchor system.
Roofing Considerations For Anchors
- Is the roof a built up or inverted assembly? This will affect the system design roof anchor tube height and the type of roof anchor flashings that need to be installed with the system. It is much more difficult to complete installations on inverted roof membranes in winter conditions.
2. Type of roof membrane: built up 4 ply asphalt and gravel, 2 ply modified bitumen, single ply PVC, TPO or EPDM. It is important to determine whether there is a roof warranty in place and specific materials that may need to be sourced to complete the roofing work required as part of the anchor installation. Roof warranty considerations will also affect who CSAI will typically work with to complete the necessary roofing work in order to maintain warranty coverage.
3. Inspect as to whether there is water or moisture present inside the roof membrane when openings are cut to install the roof anchors? If yes, then photos/videos are provided to the client to follow up with so that the roof anchor installer is not responsible for future leaks.
4. HLL – Horizontal Life Line systems are Engineered horizontal cable and posts that are a great option to allow workers to be continually tied off while accessing perimeter flashings, mechanical equipment and restricted areas on the roof.
Installation Process For Roof Anchors
When installing roof anchors on an existing structure, we go through an extensive list in order to ensure the project is carried out successfully:
- Site assessment and measurements to ensure that the building in question is viable for roof anchors.
- Roof review (as detailed above).
- Assess the access for installation.
- Put together AutoCad drawings for the project.
- Design the roof anchor system.
- Obtain design approval from a 3rd party professional engineer.
- Get project approval.
- Prepare materials and documents for the installation crew.
- Install anchors a minimum of 7 feet from the roof edge (where possible) for the safety of crew members to allow them to tie-off and complete the rest of the installation. If the minimum of 7 feet is not possible for various reasons, approach anchors and or HLL (Horizontal Lifeline Systems) are required for safe approach to install an anchoring point near perimeter.
- Once anchors are installed, installation documentation is sent to a 3rd party engineer for review.
- A maintenance logbook is prepared, and engineer sealed roof anchor drawings are delivered to the client for posting on-site at all roof entrances.
Maintenance For Roof Anchors
Typically, the lifespan for roof anchor systems is 25 – 30 years with routine inspection & maintenance (will vary based on roofing conditions). Statutory requirements include a visual inspection of anchors once per year, with adhesive anchors (adhered to concrete) are required to be load tested once every five years. Recently, requirements for inspections (Construction Use) have been updated, and now require a professional engineer to sign off on the provided certificate. In other words, when an anchoring system is about to go into use for a construction projects (ie building restoration) a professional engineer is required to sign off on the system. The signing engineer can also require functional load testing on an anchoring system to ensure the systems integrity.
When it comes to the safety of your roofing contractors and workers accessing your roof top, anchors are the preferred solution to ensure that roofing work, balcony and brick restoration, building envelope and window cleaning is performed safely. If you’re interested in installing a roof anchor system, or want more information about what installations entail, click here to contact us. The team at Elite is available 24/7 to answer your roofing questions.