Intumescent Coatings for Steel

What we protect

We apply intumescent coatings to exposed structural steel, wherever the project calls for a fire-resistance rating.

• Columns, beams and bracing in new buildings and additions.
• Exposed steel in lobbies, atriums, warehouses and process buildings.
• Equipment supports, pipe racks and process structures on industrial sites.
• Repairs and touch-ups on existing fire protection damaged by other trades.

Work is carried out by our crews and qualified subcontractors. We do not do residential work.

How it works, and who sets the thickness

An intumescent coating, often called intumescent paint, swells in the heat of a fire and forms an insulating char layer that slows the heating of the steel. At normal temperature, it looks like an ordinary paint film.

The thickness to apply and the fire-resistance rating are never set by the applicator. They come from three sources:

• The National Building Code, as adopted by the province (in Quebec, the Construction Code; in Ontario, the Ontario Building Code), which sets the rating required for the building's use.
• The project designer, who selects the design and writes it into the specification.
• The product's listed documentation: the design evaluated to CAN/ULC-S101 and published in the ULC listings, which ties together the product, the steel section and the thickness.

Our role is to apply exactly what the specification calls for, measure it and prove it. If a value is missing or conflicting, we ask the designer before starting.

Intumescent systems and when to choose each

The system depends on the fire scenario and the exposure, as defined in the specification.

• Water-based intumescent: thin film for dry, heated interiors; low odour, useful in occupied buildings. It dries slowly in cold or humid conditions.
• Solvent-based intumescent: thin film that copes better with humidity during construction and with some semi-exposed conditions, as its documentation states.
• Intumescent epoxy: a thick, hard film that resists impact, weather and chemicals. It is the choice for industrial settings exposed to hydrocarbon fires, evaluated to UL 1709.
• Primer: it must be listed among the compatible primers in the intumescent product's documentation.
• Topcoat: protects the film from moisture and provides colour, where the documentation requires or allows it.

Intumescent coating is part of our protective coatings work and can be ordered together with steel preparation.

How an intumescent job runs

An intumescent job follows six steps, with readings taken at each one.

• Specification review: listed design, thickness per steel section, permitted primer and topcoat.
• Preparation: degreasing, then blast cleaning to the grade the primer documentation requires, often SSPC-SP 6 or SSPC-SP 10.
• Primer: application, with its thickness measured before moving on.
• Intumescent: successive coats up to the specified thickness, respecting the recoat times on the data sheet.
• Topcoat: applied once the intumescent film has dried enough.
• Records: readings, data sheets, batch numbers and photos, handed to the client and the designer.

An existing primer of unknown origin is not reused without confirmed compatibility; otherwise, the steel is blast cleaned.

Thickness control and inspection

Thickness control is the core of the job: fire protection that is too thin does not deliver the intended rating.

• Wet film: measured during application, coat by coat.
• Dry film: measured after drying to SSPC-PA 2 and the method in the product documentation; the primer thickness is subtracted to get the intumescent thickness (dry film thickness).
• Recorded readings: by member, by section and by area, with the day's ambient conditions.
• Rework: any area below the specified thickness gets an additional coat and is measured again.

Final inspection belongs to the authority having jurisdiction and the professional of record. We give them access to the site and the full file.

Site conditions and safety

Intumescent coatings are sensitive to temperature, humidity and impact until fully dry. These conditions are settled in the quote.

• Temperature and humidity: monitored daily; in winter, the area must be heated and ventilated (cold-weather application).
• Sequencing with other trades: fire protection goes on before ducts, ceilings and partitions hide the steel.
• Work at height: lifts or scaffolding, depending on the structure.
• Occupied buildings: isolated zones, low-odour products, evening or weekend work where needed.

Pricing: by quote

Intumescent coating work is priced by quote. Five factors drive it:

• The number and type of steel sections, and the thickness specified for each.
• Preparation: new steel, existing primer to verify, or full blast cleaning.
• The system: water-based, solvent-based or epoxy, with or without topcoat.
• Access: height, congestion, coordination with other trades.
• The work window and the season.

Send the project specification, drawings or photos with your quote request: we reply within 24 business hours.

Where we work

Induscoat applies intumescent coatings in Montreal, across Quebec and in Ontario, working from LaSalle:

• Montreal and Montérégie
• Quebec, for the province as a whole
• Abitibi-Témiscamingue
• Côte-Nord
• Saguenay–Lac-Saint-Jean
• Mauricie–Centre-du-Québec
• Ontario

What is not covered

We do not perform fire-resistance calculations, set the required rating or select the listed design: those decisions belong to the project designer. Without a specification that states them, we cannot set a thickness.

The term "fire protection coating" is also used for other products: firestop systems for wall penetrations, fire-retardant paints for wood, spray-applied materials. Our service covers structural steel.

If the steel is heavily rusted or carries old paint that is peeling, it first needs abrasive blasting. If the structure only needs corrosion protection, see steel structure painting.

Typical Problems We Solve

• Exposed steel that must meet a fire-resistance rating without cladding
• Thickness readings missing or not recorded, blocking acceptance of the work
• Existing primer of unknown compatibility with the intumescent product
• Fire protection damaged by other trades during construction

What You Receive

• Quote based on the specification: listed design, thickness per steel section, primer and topcoat
• Steel prepared to the grade the primer documentation requires, compatible primer applied
• Wet and dry film thickness readings recorded by member, with primer thickness subtracted
• Close-out file with data sheets, batch numbers, readings and photos for the authority having jurisdiction

Timeline

Standards & Certifications

• CAN/ULC-S101: fire endurance tests of building construction and materials
• UL 1709: rapid rise fire tests of protection materials for structural steel
• National Building Code of Canada, as adopted by the province: fire-resistance ratings
• SSPC-PA 2: dry film thickness measurement

Industries We Serve

• Commercial and institutional buildings: exposed steel in lobbies and atriums
• Warehousing and logistics: columns and roof structures
• Manufacturing and processing: process buildings, mezzanines, equipment supports
• Petrochemical and energy: pipe racks and structures exposed to hydrocarbon fire

Service FAQ

Technical guides

• Dry film thickness
• NACE No. 2 / SSPC-SP 10 surface preparation
• Cold-weather epoxy application and winter shutdowns
• Coating failure modes and diagnosis

Related applications

Concrete industrial use cases where this service is applied.