Does Fiberglass Rebar Meet Code? CSA S807 and S806 Explained

Fiberglass (GFRP) rebar can meet code in Canada, but not by default. The bar itself is covered by CSA S807, building design with it is covered by CSA S806, and bridge design by CSA S6, Section 16. The 2024 Ontario Building Code does not reference S806 or S807, and its prescriptive Part 9 rules assume steel bar, so in a building GFRP is normally used through an engineer's design submitted as an alternative solution. On provincial bridges, MTO has its own specifications that accept a specific grade of GFRP.

The standards that cover GFRP rebar

Several standards come up whenever fiberglass rebar is specified. They do different jobs:

The split matters. A bar that complies with S807 is not, by itself, a code-compliant structure. The structure also has to be designed for FRP using S806, S6 or an equivalent method, because the design rules for steel in CSA A23.3 do not apply to a material that behaves this differently.

What CSA S807 covers

CSA S807 sets the material and manufacturing requirements for FRP bars and grids used as non-prestressed internal reinforcement in concrete: bridges, buildings, marine structures and so on. The 2019 edition covers bars made with glass, carbon, aramid or basalt fibres in polyester, vinylester or epoxy resins. It added basalt and limited glass fibre to the corrosion-resistant E-CR type.

S807 classifies bars by:

• Fibre type. Glass is by far the most common in construction (that is the "G" in GFRP).
• Grade, based on modulus of elasticity. Grade III is the stiffest, with a minimum modulus of 60 GPa. Manufacturers list Grades I and II at lower minimum moduli (40 and 50 GPa). A higher modulus means less deflection and narrower cracks for the same amount of bar.
• Durability class. D1 is the higher durability class. Resin type plays a big part; vinylester and epoxy resins are associated with the higher class.
• Strength. Bars have guaranteed minimum tensile strengths, which drop as bar diameter increases.

A note on sizes. S807 identifies bars by a designated diameter and a nominal area, not by the "M" sizes used for steel. Some suppliers still label GFRP bars 10M or 15M, but those labels do not guarantee the same area as steel bar of the same name, so order and check GFRP by the nominal area and grade on the drawings. Our GFRP vs steel comparison shows where the areas differ.

What CSA S806 and CSA S6 add

CSA S806 covers the design and evaluation of FRP building components and of building components reinforced with FRP. It is a limit states design standard consistent with the National Building Code of Canada, which is what lets an engineer use it alongside the rest of the code. The 2026 edition added basalt, made its fire resistance annex mandatory, expanded seismic provisions and added a climate resiliency annex.

CSA S6 Section 16 does the same for bridges designed under the Canadian Highway Bridge Design Code. In the current S6:25 edition it covers glass, carbon, aramid and basalt fibres.

The engineering differences these standards handle include: GFRP does not yield (it stays elastic until it ruptures), it is far less stiff than steel, it has limits on sustained stress over time (creep rupture), it loses strength at elevated temperatures, and bends must be made at the factory. Those differences are what the comparison of GFRP and steel on a real job comes down to.

What the Ontario Building Code says

The 2024 Ontario Building Code (O. Reg. 163/24, in force January 1, 2025) adopts the National Building Code of Canada 2020 with Ontario amendments. For reinforced concrete:

• Part 4 (engineered design) requires concrete buildings and members to conform to CSA A23.3. The code's referenced documents list includes A23.3, A23.1 and G30.18 for steel bar, but no FRP standard: S806 and S807 are not referenced.
• Part 9 (houses and small buildings) sends most reinforced concrete to Part 4. Where Part 9 does give prescriptive rebar rules, such as flat ICF walls and reinforced slabs over cold rooms, it calls for steel bar to CSA G30.18 with a 400 MPa yield strength.

So a contractor cannot swap GFRP into a Part 9 ICF wall or footing detail on their own. The code route is the alternative solution: Division A allows a design that achieves the level of performance of the code's acceptable solutions, and Division C sets out how it must be documented for the chief building official. In practice that means an engineer designs the element to CSA S806, documents why it performs at least as well as the code requires, and the building department accepts it.

Some uses are less demanding. Where the code does not require reinforcement at all, for example in many floors on ground, the choice of reinforcement is up to the designer. That still deserves a designer's sign-off, because GFRP behaves differently in a slab than steel does. For how the steel side of the code fits together, see rebar code requirements in Ontario.

How MTO treats GFRP in Ontario

The Ministry of Transportation has the most established GFRP rules in the province. MTO began specifying GFRP as a premium reinforcement in 2005, and its 2024 premium reinforcement memo for bridges lists Grade III (60 GPa) GFRP alongside stainless steel for elements such as deck top mats on high-traffic routes and barrier walls. MTO's provincial specifications set out the details:

• OPSS.PROV 1640 (material). GFRP bars must be Grade III with durability class D1 to CSA S807, made with vinylester or epoxy resin and E-CR glass, and come from a manufacturer on MTO's Designated Sources for Materials list. It also sets minimum glass content, glass transition temperature and elongation values.
• OPSS.PROV 950 (construction). Field bending is not permitted, bent bars must not be field cut, and straight bars can only be cut on site with written permission, using a saw. Ties must be coated, stainless or nylon, chairs must be non-metallic, and bars stored for more than 30 days must be covered with opaque white sheeting.

MTO accepts glass fibre only, so basalt bars that comply with S807 are not an option on MTO work. Municipal owners often follow MTO practice or have their own specifications, so check the contract documents.

What to ask for when GFRP is specified

If GFRP is on your drawings, or you are proposing it, ask for:

1. The standard and grade. CSA S807, grade (I, II or III) and durability class, matched to what the engineer specified.
2. Mill certificates or test reports showing the bar meets that grade.
3. Nominal areas, not just size labels, so the bar list matches the design.
4. Bent shapes ordered up front. Bends cannot be made on site, so every hook, stirrup and corner bar has to be on the bar list before production.
5. Handling and cutting rules for the site crew, including supports and ties.
6. Lead time, since bent GFRP shapes are made to order.

Our guide to buying GFRP rebar in Ontario covers ordering in more detail.

Getting GFRP right on your project

GFRP is a good answer to corrosion, but code compliance depends on the design, not just the bar. Bring the engineer in early, confirm the grade and standard on the drawings, and check with the building department before you commit if the project is under Part 9.

We supply GFRP rebar alongside steel bar, detailed and tagged to your bar list. Send us your drawings for a quote, or see our rebar products.