A roof anchor is the fixed point a worker's harness lanyard or self-retracting lifeline connects to on a roof. Choosing one comes down to four things: whether it is temporary or permanent, what the roof deck is made of, whether the system is fall restraint or fall arrest, and the anchor strength your province requires. This guide covers the types, the Canadian strength figures, and the 3M DBI-SALA roof anchors ERE Inc. supplies.
In this guide
- What is a roof anchor?
- What are the types of roof anchor?
- How strong does a roof anchor have to be in Canada?
- Is a roof anchor for fall restraint or fall arrest?
- Which roof anchors does ERE supply?
- How to choose a roof anchor
- Frequently asked questions
What is a roof anchor?
A roof anchor is an anchorage connector fixed to the roof structure that gives a personal fall protection system a secure attachment point. The standard that covers these devices in Canada is CSA Z259.15, which sets performance, design, testing and marking requirements for anchorage connectors. The CCOHS fall protection page explains where a fall protection plan is needed in the first place.
The anchor connects to a body-worn system, so it works together with a harness and a lanyard or lifeline. If you are still selecting those parts, see our guides to the fall arrest harness and the self-retracting lifeline.
What are the types of roof anchor?
Roof anchors are grouped by how long they stay on the roof and by the deck they fasten to. The first split is permanent versus temporary:
- Permanent roof anchors: installed once and left in place for repeated access, such as HVAC servicing or window cleaning. They are normally flashed into the roofing so the roof stays watertight.
- Temporary roof anchors: installed for a project and removed at the end. Reusable hinged anchors and roof top anchors belong here.
The second split is the roof deck. Wood-frame roofs take bolt-on or nail and screw anchors, metal decking takes screw-on or clamp styles, and concrete roofs take concrete D-ring anchors. Sloped roofs often need a hinged anchor that conforms to the pitch. Always read the manufacturer's data sheet for the substrates, slope and fasteners it was tested on.
How strong does a roof anchor have to be in Canada?
It depends on the province and on whether the system is arrest or restraint, because there is no single national figure. 3M Canada's Anchorage Strength Requirements: Canada collects the regulation text by jurisdiction, and its general convention for fall arrest is 22.2 kN (5,000 lb) per attached worker for non-certified anchorages. A certified anchorage designed by a qualified person or engineer can instead be rated at two times the maximum arresting force.
| Jurisdiction | Fall arrest anchor requirement (as quoted by 3M Canada) |
|---|---|
| Alberta | 16 kN per attached worker or two times the maximum arresting force, permanent and temporary |
| British Columbia | 22 kN (5,000 lb) or two times the maximum arrest force |
| Ontario (construction) | Temporary support: 8 kN static force, or 6 kN where a shock absorber is also used; permanent anchor systems are installed to the Building Code |
| Quebec | Breaking strength of at least 18 kN, or an engineered system, or a device certified to EN 795 or CAN/CSA Z259.15 |
| Saskatchewan, Northwest Territories | Breaking strength of at least 22.2 kN |
| Nova Scotia | 22 kN for a non-engineered anchorage, or two times the maximum arresting force if engineered |
These figures are summaries, and regulations are amended, so check the current text for the province where the roof is. When more than one worker connects to the same anchor, the strength has to be multiplied by the number of workers attached.
Is a roof anchor for fall restraint or fall arrest?
A roof anchor can serve either, but the load it must carry is very different. Fall restraint keeps a worker from reaching the edge at all, so the anchor sees a small load. Fall arrest stops a fall that has already happened, so the anchor must absorb the full arresting force.
Ontario's construction regulation, for example, sets 2 kN for a temporary support in a travel restraint system against 8 kN in a fall arrest system. British Columbia gives 3.5 kN for a temporary restraint anchor against 22 kN for fall arrest. Because of that gap, an anchor labelled for restraint only must never be used for arrest, and some provinces, such as Alberta, require it to be permanently marked for restraint only.
Which roof anchors does ERE supply?
ERE Inc. supplies roof anchors in the 3M DBI-SALA and 3M Protecta PRO ranges, each for a different roof. Specifications below come from the product listings, so confirm ratings on the data sheet for your installation.
- 3M DBI-SALA Permanent Roof Anchor with Flashing & Cap installs up to a 2 in. x 8 in. wood frame structure with a bolt and clamp installation, and has an integral stainless steel D-ring tie-off point.
- 3M DBI-SALA Reusable Hinged Roof Anchor installs to sloped or flat wood and metal decking roofs by nail or screw, with the fastener kit included and a hinged design with D-ring.
- 3M DBI-SALA Roof Top Anchor installs to 24-gauge or thicker metal, 5/8 in. wood and 3,000 PSI concrete roofs, accommodates roof ribs 10 to 20 in. apart and suits flat or sloped decks up to 3:12 pitch.
- 3M PROTECTA PRO Reusable Hinged Roof Anchor is the Protecta PRO temporary-use hinged option for roof work.
Related anchorage options for other structures include the concrete D-ring anchors, the fixed beam anchors and the web tie-off adaptor. The full range is on the fall protection collection.
How to choose a roof anchor
- Identify the roof deck. Wood frame, metal deck, standing seam or concrete decides which anchor can be fastened without damaging the roof.
- Decide temporary or permanent. One-off projects suit reusable anchors; repeat access suits a permanent, flashed anchor.
- Set the system type. Restraint or arrest, because that sets the load the anchor is rated for.
- Check the provincial figure. Use the current regulation for the province, and multiply for each worker attached.
- Confirm the roof structure. The anchor is only as strong as the rafters, deck or concrete under it, and a qualified person should assess that.
- Match the connector and lifeline. The lanyard, SRL and connector must be rated for the same use, with a rescue plan before work begins.
Not sure which anchor suits your roof? Request a quote and we will match the anchor to the deck and the system, or call us in Montreal.
Need help with roof anchors?
ERE Inc. has been Canada's environmental and safety equipment specialist for 30+ years. Talk to a real specialist about your roof and your fall protection plan.
→ Request a Quote | 1-888-287-EREC | Browse Fall Protection | sales@ereinc.com
Frequently Asked Questions
Are roof anchors permanent?
Some are and some are not. A permanent roof anchor is installed once and flashed into the roofing for repeated access, while a temporary roof anchor is fastened for one project and removed afterwards. The listing for each product states which use it is intended for.
How much weight does a roof anchor support?
For fall arrest, a common Canadian convention is 22.2 kN (5,000 lb) per attached worker for a non-certified anchorage, and provincial figures run from 16 kN in Alberta to 18 kN in Quebec. Restraint anchors carry far less, such as 2 kN to 3.5 kN for a temporary anchor.
Can you use one roof anchor for two workers?
Only if it is rated for it. When more than one fall arrest system is attached to an anchorage, the required strength is multiplied by the number of systems attached, so a single-worker anchor is not a shared anchor.
Do roof anchors need to be inspected?
Yes. Follow the manufacturer's inspection and service instructions, and remove an anchor from service after a fall or if the anchor, fasteners or substrate show damage. A qualified person should assess the roof structure before use.
Related articles
- Self-retracting lifeline: CSA classes and how to choose
- Fall arrest harness: how to read CSA Z259.10 classes
Lire en français : Ancrage de toit : types, résistance et choix au Canada