Codes, Standards, and Quality Assurance
Introduction to the Canadian Regulatory Framework
The roofing trade in Canada is governed by a set of codes, standards, and quality assurance requirements designed to ensure the safety, durability, and performance of roofing systems. For the Red Seal exam, you must master not only installation techniques but also the regulatory framework that governs your work. This chapter covers the essential regulatory documents, their practical applications, and the quality assurance procedures every journeyman roofer must know.
Hierarchy of Regulatory Documents
In Canada, the hierarchy of documents governing your work is as follows:
6.The National Building Code of Canada (NBC) – Reference document published by the National Research Council of Canada (NRC). It establishes minimum design and construction requirements.
7.Provincial and territorial codes – Each province adopts the NBC with local amendments. You must always verify the code in effect in the province where you are working.
8.CSA standards – Developed by the CSA Group (Canadian Standards Association), these specify technical requirements for materials and test methods.
9.CGSB standards – From the Canadian General Standards Board, these cover roofing material specifications, among other things.
10.Manufacturer design guides – Technical documents published by roofing system manufacturers that specify installation conditions and warranties.
11.Project specifications – Contractual documents prepared by the architect or engineer for a specific project.
Golden Rule: In the event of a conflict between documents, the contractual document (specifications) takes precedence, provided it meets the minimum requirements of the code. The code is a minimum, never a maximum.
National Building Code – Relevant Provisions
Section 9.26 – Roof Covering
The NBC devotes Section 9.26 to roof coverings for small buildings (houses and small buildings). Key requirements include:
Article 9.26.2.1 – The minimum slope for an asphalt shingle roof covering is 1:4 (14°). Below this slope, you must use a roofing system designed for flat or low-slope roofs.
Article 9.26.2.2 – The roof covering support must be continuous and capable of supporting the expected loads.
Article 9.26.3.1 – Air barriers and vapour barriers must be installed in accordance with the requirements of Section 9.25 to prevent condensation within the roof assembly.
Article 9.26.4.1 – Underlayment (felt paper or synthetic membrane) must be installed over the roof sheathing before shingles are applied. For slopes of 1:4 to 1:2, a Type 1 or Type 2 underlayment is required. For slopes less than 1:4, a Type 2 underlayment with sealed joints is required.
Table 9.26.4.1 – Underlayment Types:
| Type | Material | Minimum Weight | Typical Use |
|---|
| Type 1 | Asphalt-saturated felt paper | 55 g/m² | Slopes ≥ 1:2 |
| Type 2 | Asphalt-saturated felt paper | 110 g/m² | Slopes 1:4 to 1:2 |
| Type 3 | Synthetic membrane | Variable | All slopes, better tear resistance |
Section 9.26.7 – Asphalt Shingles
Article 9.26.7.1 – Asphalt shingles must conform to CSA A123.1/A123.2 or ASTM D225.
Article 9.26.7.2 – Installation must conform to the manufacturer's instructions, but at minimum:
Minimum lap of 50 mm (2 in) for three-tab shingles.
Fasteners must penetrate at least 19 mm (3/4 in) into the sheathing or through the thickness of the sheathing if it is thinner.
Four fasteners per shingle for normal slopes; six fasteners for slopes greater than 1:1 or in high-wind regions.
Article 9.26.7.3 – For slopes of 1:4 to 1:2, underlayment must be applied double over eaves and valleys, with a minimum width of 900 mm (36 in) centred on the valley.
Section 9.26.9 – Low-Slope and Flat Roofs
Article 9.26.9.1 – Built-up roofing (BUR) membranes must conform to CAN/CGSB-37.51.
Article 9.26.9.2 – Elastomeric membranes (EPDM, PVC, TPO) must conform to applicable standards and be installed according to manufacturer specifications.
Article 9.26.9.3 – The minimum slope for a flat roof is 1:50 (2%) to ensure water flows toward drains. This slope can be achieved through structural slope or tapered insulation.
Requirements for Large Buildings (Section 3)
For high-rise or commercial buildings, Section 3 of the NBC applies. Roof covering requirements are less detailed there, but fire resistance, fire behaviour, and structural stability requirements are more stringent. Roof coverings must be classified according to their fire behaviour (Class A, B, or C) in accordance with CAN/ULC-S107.
| Class | Description | Examples |
|---|
| A | Highest fire resistance | Asphalt shingles with mineral surface, clay tiles, slate |
| B | Moderate fire resistance | Asphalt shingles without mineral surface, some membrane systems |
| C | Minimum fire resistance | Some wood shingles, unprotected membranes |
CSA and CGSB Standards for Roofing Materials
CSA Standards for Asphalt Shingles
The CSA A123 series of standards covers asphalt shingles and related products:
CSA A123.1/A123.2 – Mineral-surfaced asphalt shingles, with or without tabs. This standard specifies manufacturing requirements, dimensions, asphalt content, tear resistance, and pull-out resistance.
CSA A123.3 – Asphalt felt underlayment for roofing.
CSA A123.4 – Asphalt felt underlayment with aluminum coating.
CSA A123.5 – Asphalt shingles with aluminum coating.
CSA A123.17 – Synthetic underlayments for roofing.
Exam Points: The weight of asphalt shingles is expressed in pounds per square (100 ft²). A standard shingle weighs between 65 and 90 lb per square. Premium (architectural) shingles weigh between 110 and 130 lb per square. The standard width of a shingle is 36 in (914 mm), and the exposed height is 5 in (127 mm) for three-tab shingles.
CGSB Standards for Membranes
CAN/CGSB-37.51 – Hot- or cold-applied built-up membrane (BUR). This standard specifies requirements for bitumen-based systems.
CAN/CGSB-37.54 – Elastomeric sheet membrane (EPDM) for roofing.
CAN/CGSB-37.56 – PVC (polyvinyl chloride) membrane for roofing.
CSA Standards for Thermal Insulation
CSA A101 – Rigid polyurethane foam insulation.
CSA A102 – Expanded polystyrene (EPS) insulation.
CSA A103 – Extruded polystyrene (XPS) insulation.
CAN/ULC-S701 – Standard for polystyrene thermal insulation.
Table of Typical R-Values:
| Insulation Material | R-Value per Inch (RSI per mm) | Use |
|---|
| Expanded polystyrene (EPS) | R-3.85 (0.026) | Flat roofs, underlayment |
| Extruded polystyrene (XPS) | R-5.0 (0.035) | Flat roofs, inverted roofs |
| Rigid polyurethane | R-6.25 (0.044) | Flat roofs, tapered insulation |
| Mineral wool | R-4.0 (0.028) | Fire protection, acoustic insulation |
| Fibreglass | R-3.3 (0.023) | Ventilated sloped roofs |
Canadian Electrical Code – Chapter V
The Canadian Electrical Code, Part I (CE Code) (C22.1) applies to electrical installations, including those that pass through or are installed on roofs. Although you are not an electrician, you must know certain rules to coordinate your work:
Rule 8-200 – Electrical demand calculation. This rule determines a building's electrical load, which influences the size of electrical panels and conduits that may pass through your roof.
Rule 12-012 – Cables and conduits installed outdoors must be supported at maximum intervals of 1.5 m (5 ft) for cables and 3 m (10 ft) for rigid conduits.
Rule 12-108 – Conduits that pass through a roof must be fitted with a flashing or protective cap to prevent water infiltration.
Exam Point: When you install flashing around an electrical conduit, the flashing must be sealed watertight, and the conduit must be raised at least 150 mm (6 in) above the roof surface.
CSA B149.1 – Natural Gas and Propane Code
The CSA B149.1 standard applies to the installation of natural gas and propane appliances. Vents and chimneys that pass through the roof must comply with specific clearances:
Article 8.14.2 – Vents must extend at least 300 mm (12 in) above the roof surface, measured at the lowest point of the vent.
Article 8.14.3 – Vents must extend at least 600 mm (24 in) above any obstacle (wall, parapet) located within 3 m (10 ft) horizontally.
Article 8.14.4 – Vents that pass through a roof must be fitted with a watertight flashing and a rain cap.
Table of Vent Clearances:
| Situation | Minimum Clearance |
|---|
| Vent passing through the roof | 300 mm (12 in) above the point of penetration |
| Vent near a wall or parapet within 3 m | 600 mm (24 in) above the obstacle |
| Vent near a window or door | 1 m (3 ft) horizontally |
| Vent near a roof fan | 1.2 m (4 ft) horizontally |
Quality Assurance – Procedures and Documentation
Quality Assurance Plan (QAP)
The quality assurance plan is a document that describes the quality control and verification procedures for a roofing project. It includes:
77.Project description – Scope of work, materials, systems.
78.Responsibility chart – Who does what, who verifies what.
79.Control procedures – Mandatory inspection points, inspections.
80.Verification procedures – Testing, sampling, documentation.
81.Non-conformance management – How to address deviations from specifications.
Mandatory Hold Points
Hold points are stages in the work where an inspection is required before proceeding. For a roof, typical hold points are:
| Hold Point | Timing | Inspector | Criteria |
|---|
| Roof deck | Before underlayment installation | Foreman, engineer | Flatness, dryness, cleanliness |
| Vapour barrier | Before insulation | Foreman | Continuity, joint sealing |
| Insulation | Before membrane | Foreman | Thickness, joint coverage, slope |
| Underlayment | Before final covering | Foreman | Overlap, fastening, sealing |
| Membrane | After installation | Foreman, manufacturer | Thickness, adhesion, seams |
| Flashings and penetrations | After membrane | Foreman | Watertightness, clearances |
Testing and Verification
Moisture test – Measurement of roof deck moisture content using a moisture meter. The deck must have a moisture content below 20% for wood decks and below 4% for concrete decks before membrane installation.
Adhesion test – For adhered membranes, a peel test is performed to verify that adhesion conforms to manufacturer specifications. The minimum peel strength is typically 2.5 kN/m² (50 lb/ft²).
Watertightness test – For flat roofs, a flood test or spray test is performed after membrane installation to verify watertightness. The water level is maintained for 24 to 48 hours.
Thermographic inspection – Use of an infrared camera to detect areas of moisture or insulation deficiency in existing flat roofs.
Site Documentation
Site documentation is essential for quality assurance. It includes:
Site journal – Daily records of work performed, weather conditions, personnel on site.
Material register – Certificates of conformity, lot numbers, delivery dates.
Inspection reports – Results of inspections at each hold point.
Non-conformance register – Description of deviations, corrective actions, verification.
Warranty records – Manufacturer and installer warranty certificates.
Warranties and Installer Certification
Types of Warranties
| Warranty Type | Coverage | Typical Duration | Conditions |
|---|
| Materials warranty | Manufacturing defects in materials | 10 to 30 years | Installation conforms to specifications |
| System warranty | Performance of the complete system | 10 to 20 years | Installation by a certified installer |
| Workmanship warranty | Installation defects | 2 to 5 years | Provided by the contractor |
| Watertightness warranty | Absence of leaks | 5 to 15 years | Regular maintenance required |
Requirements for Certified Installers
Roofing system manufacturers often require certification to offer a system warranty. Typical requirements are:
Complete technical training on the system.
Minimum experience (usually 2 to 5 years).
Passing a certification exam.
Periodic renewal of certification (every 2 to 3 years).
Compliance with supervision ratios (one certified supervisor for a maximum number of apprentices).
Common Pitfalls to Avoid
110.Confusing underlayment types – Table 9.26.4.1 of the NBC specifies underlayment types based on slope. Using a Type 1 underlayment on a 1:4 slope is a frequent error.
111.Ignoring the minimum slope for asphalt shingles – The 1:4 minimum slope is an absolute requirement. Below this slope, asphalt shingles are not permitted, even with a Type 2 underlayment.
112.Forgetting vent clearances – The clearances in CSA B149.1 are often overlooked. A vent that is too short can cause dangerous gas backdrafting.
113.Neglecting documentation – Lack of inspection documentation can void the manufacturer's warranty. Document every hold point.
114.Using inadequate fasteners – The number of fasteners per shingle is specified in the NBC. In high-wind regions, the number must be increased.
115.Installing membranes in wet conditions – Bituminous and elastomeric membranes must not be installed on a wet deck or in rainy weather. Deck moisture content must be verified.
116.Confusing CSA and CGSB standards – CSA standards cover materials (shingles, insulation), while CGSB standards cover systems (membranes). Verify the applicable standard for each product.
117.Forgetting flashings at penetrations – Every penetration (conduit, vent, antenna) must have an individual flashing. A poorly installed flashing is the most common cause of leaks.
118.Not verifying material conformity – Materials must bear the appropriate certification mark (CSA, CGSB, ULC). A missing mark may indicate a non-conforming product.
119.Ignoring ventilation requirements – Ventilation of the roof space is governed by the NBC (Section 9.19). Inadequate ventilation causes condensation and reduces the lifespan of the roof covering.
Summary
The NBC is the primary reference document for minimum construction requirements. Section 9.26 covers roof coverings for small buildings.
The minimum slope for asphalt shingles is 1:4 (14°). Below this, use a flat-roof system.
Underlayments are classified as Types 1, 2, and 3 based on weight and use. Type 2 is required for slopes of 1:4 to 1:2.
CSA A123 standards cover asphalt shingles and underlayments. CGSB 37 standards cover roofing membranes.
The Canadian Electrical Code, Part I and CSA B149.1 govern roof penetrations for electrical conduits and gas vents.
Hold points are mandatory inspection stages. Document each inspection to preserve warranties.
Manufacturer warranties are conditional on compliant installation and complete documentation.
Deck moisture content must be verified before membrane installation: < 20% for wood, < 4% for concrete.
Watertightness tests (flood or spray) are required for flat roofs after membrane installation.
Self-Assessment Questions
133.What is the minimum slope for installing asphalt shingles according to the NBC?
134.What are the three types of underlayments according to the NBC, and what are their uses?
135.Which CSA standard covers mineral-surfaced asphalt shingles?
136.What is the minimum clearance for a gas vent passing through a roof according to CSA B149.1?
137.What are the mandatory hold points for a roofing project?
138.What is the maximum moisture content for a concrete deck before membrane installation?
139.What is the difference between a materials warranty and a system warranty?
140.What are the fastening requirements for asphalt shingles in high-wind regions?
141.Which CGSB standard covers built-up membranes (BUR)?
142.Why is inspection documentation essential for warranties?
Answers: 1) 1:4 (14°); 2) Type 1 (55 g/m², slopes ≥ 1:2), Type 2 (110 g/m², slopes 1:4 to 1:2), Type 3 (synthetic, all slopes); 3) CSA A123.1/A123.2; 4) 300 mm (12 in) above the point of penetration; 5) Deck, vapour barrier, insulation, underlayment, membrane, flashings; 6) 4%; 7) The materials warranty covers manufacturing defects, the system warranty covers complete performance; 8) Six fasteners per shingle; 9) CAN/CGSB-37.51; 10) Documentation is required to validate installation conformity and preserve manufacturer warranties.
