Structural steel frames
Columns and beams carrying the building. Unprotected steel loses strength as it heats, which is the entire reason applied protection exists.
Service
Fireproofing Contractor in Mississauga
Spray-applied cementitious fire-resistive material and intumescent coatings for structural steel in commercial and industrial buildings across the GTA.
- What it does
- Delays structural heating so the frame keeps its strength
- Two systems
- Cementitious SFRM and intumescent coatings
- Driven by
- The project specification and the tested assembly
- Cost driver
- Thickness, steel surface area, access and prep
Fireproofing is the application of fire-resistive materials to structural elements so they retain strength for longer in a fire. NorthStar applies both cementitious spray-applied fire-resistive material and intumescent coatings to structural steel in commercial and industrial buildings, working to each project’s specification.
A note on the word “fireproofing”
“Fireproofing” is the common name for this trade, and it is what people search for, so we use it. But it describes the goal poorly. These materials do not make a building fireproof. They slow the rate at which structural steel heats up in a fire, so the structure keeps its strength for a defined period — time for occupants to get out and for the fire service to work. The accurate term is fire-resistive material or passive fire protection.
What passive fire protection does
Structural steel is strong, but it loses strength as it gets hot. In an uncontrolled fire, unprotected steel can reach temperatures at which it deforms well before the fire burns itself out. When a beam or column deforms, the structure above it moves.
Passive fire protection addresses this by putting an insulating layer between the fire and the steel. “Passive” distinguishes it from active systems such as sprinklers and alarms: it requires no detection, no power and no water supply. It is simply there, doing its job from the moment it is applied.
The performance is expressed as a period of fire resistance. That period is not chosen by the applicator — it comes from the building code as applied to the specific building by the design team, and it flows down to us as a specification.
Cementitious spray-applied fire-resistive material
Cementitious SFRM is a cement-based material, mixed with water on site and spray-applied in a relatively thick layer directly onto the steel. Once cured it forms a rigid, insulating coating that keeps heat away from the member beneath.
Practical characteristics:
- Applied thickly relative to intumescent coatings
- Textured, utilitarian appearance — it is not a finish coating
- Normally used where the steel will be concealed by ceilings, cladding or shafts
- Efficient to apply over large areas of structure
- Generally the lower-cost option per unit of protected area
- Thickness is the controlling variable and is verified during application
This is the workhorse product on most commercial and industrial structural steel: floor beams above a ceiling, columns inside walls, deck framing, and structure in service areas.
Intumescent coatings
Intumescent materials work differently. They are applied thin — closer to a heavy paint than to a plaster — and they stay thin under normal conditions. When exposed to sufficient heat, they react and swell into a thick insulating char, forming the protective layer at the moment it is needed.
Practical characteristics:
- Thin film in service, so the shape of the steel remains visible
- Can be finished to an acceptable appearance where steel is exposed by design
- Used where architectural intent calls for visible structure
- More demanding on surface preparation than SFRM
- Generally higher cost per unit of protected area
- Dry film thickness is the controlling variable and is measured during application
Exposed structural steel in a lobby, an atrium, a feature staircase or a design-led retail interior is where intumescent coatings usually appear.
Choosing between them
| Cementitious SFRM | Intumescent coating | |
|---|---|---|
| Applied thickness | Thick | Thin film |
| Appearance | Textured, utilitarian | Smooth, can be finished |
| Typical location | Concealed structure | Exposed, architectural structure |
| How it works | Insulates continuously | Expands into a char when heated |
| Surface preparation | Important | Critical |
| Relative cost | Lower | Higher |
On most projects the choice has already been made by the design team before we are involved, and it comes down to whether the steel will be seen. Where it has not been settled, we are happy to talk through the practical implications of each — but the specification decision sits with the architect and engineer of record.
Structural steel applications
- Columns
- Beams and girders
- Joists and open-web steel joists
- Steel deck and floor assemblies
- Bracing and connections
- Steel within shafts, stairwells and service risers
Commercial and industrial projects
We apply fire-resistive materials on:
- New commercial construction — offices, retail, mixed-use
- Industrial buildings, warehouses and distribution centres
- Manufacturing facilities
- Parking structures
- Base-building work and core-and-shell projects
- Retrofit and repair of existing protection disturbed by renovation work
That last one is more common than people expect. Any renovation that cuts into a protected floor assembly — new services, new penetrations, altered ceilings — damages existing fire protection that then has to be made good. It is easy to overlook and straightforward to put right if it is caught.
Related: commercial insulation, industrial insulation, and work for builders and general contractors.
Surface preparation
Fire-resistive materials only perform if they stay attached to the steel, and adhesion is decided by what is underneath. Preparation is not a formality.
- Steel must be clean — free of oil, grease, dirt and loose material
- Loose mill scale and rust removed
- Existing primers must be compatible with the fire protection product
- Surfaces dry, and within the temperature range the product requires
- Adjacent finishes, services and equipment masked and protected
Primer compatibility is worth raising early
Shop primer applied to structural steel is not automatically compatible with every fire protection product. Where there is any doubt, it is far cheaper to confirm compatibility at shop drawing stage than to discover an adhesion problem after the steel is erected. We raise it at tender review.
The application process
- Specification review. We read the fire protection specification, the schedule of members and the required ratings, and check them against the steel as detailed.
- Coordination. Sequencing agreed with the general contractor — fire protection has to go on before ceilings, ducts and services close in the structure.
- Preparation and masking. Surfaces prepared, surroundings protected, containment set up.
- Application. Material applied to the specified thickness. Where more than one pass is needed, subsequent passes follow the product’s requirements.
- Thickness verification. Checked during application, not after the fact — this is the measurement that determines whether the work meets its specification.
- Curing. Conditions maintained as the product requires.
- Patching. Areas damaged by following trades made good before close-in.
- Documentation and clean-up. Records completed, masking and debris removed.
Inspection and documentation
Applied fire protection is inspected, and the inspection is meaningful because the performance is invisible once the ceiling is up. Depending on the project, that can involve thickness measurement, adhesion or bond testing, density verification and a visual review for coverage and damage.
We keep records of what was applied, where, to what thickness, and when, and provide them for the project file. Where a third-party inspection or testing agency is engaged, we coordinate access so the work can be verified before it is covered up.
Working to tested assemblies
Fire-resistance ratings come from standardised furnace tests of complete assemblies — a specific product, at a specific thickness, on a specific member profile, in a specific configuration. A rating belongs to that assembly, not to the product on its own.
In practice this means the specified design has to be followed precisely: the product named, at the thickness scheduled, over a compatible substrate, on the member profile it was tested against. Substitutions are not a field decision.
What we do not claim
This page deliberately does not list fire ratings, tested assembly designs, certification numbers or code approvals. Those are project-specific and must be verified against the actual specification and the actual products used — quoting them generically on a web page would be misleading.
Send us your specification and we will confirm in writing what we can deliver against it.
What affects the cost
- Material type — intumescent is generally more expensive than cementitious SFRM
- Required rating — a longer period means more thickness
- Steel surface area — driven by member sizes and profiles, not just floor area
- Member profile — complex sections have more surface to cover
- Access — height, lift requirements, congested areas
- Surface preparation — condition of the steel and primer compatibility
- Protection and containment — much higher in occupied or finished buildings
- Scheduling — phased work, night or weekend access
- Inspection requirements
Frequently asked questions
Does fireproofing make a building fireproof?
No, and the industry term is misleading. Applied fire protection is designed to delay the point at which a structural member loses strength in a fire, buying time for occupants to evacuate and for the fire service to respond. It does not make a structure immune to fire. The accurate description is fire-resistive material, or passive fire protection.
What is the difference between cementitious SFRM and intumescent coating?
Cementitious spray-applied fire-resistive material is a thicker, cement-based product that insulates the steel from heat. Intumescent coating is a thin paint-like product that reacts to heat by expanding into an insulating char layer. SFRM is generally used where it will be concealed; intumescent is used where the steel stays visible.
Which fire rating will my project need?
That is determined by the building code, the occupancy, the building height and area, and the design decisions made by the project architect and engineer — not by the applicator. We work to the ratings and assemblies specified for your project. If the specification is not settled yet, that conversation belongs with your design team.
Can fireproofing be applied to an occupied building?
Sometimes, with the work area isolated and the sequencing agreed in advance. Overspray control and access are the practical constraints. On retrofit work in occupied buildings we plan phasing with the property manager or general contractor before starting.
Do you provide documentation of the work?
Yes. We record what was applied, where, and to what thickness, and we make that record available for the project file and for inspection. The specific documentation required varies between projects, so we confirm the requirement before starting.
Do you do fire-stopping as well?
Fire-stopping — sealing penetrations through fire-rated walls and floors — is a related but distinct trade to spray-applied fire protection. Tell us the full scope when you enquire and we will confirm what we can cover on your project.
Applications
Where applied fire protection is used
Passive fire protection buys time. It does not stop a fire; it slows the rate at which structure loses its strength, which is what makes egress and fire-fighting possible.
Metal roof and floor decks
Underside protection to the deck and its supporting members, generally sprayed before the ceiling systems below are installed.
Warehouse and distribution buildings
Long clear spans with exposed structure, where the steel is both the frame and the visible ceiling.
Parking structures and service areas
Exposed structure below occupied floors, often in conditions that influence which of the two systems is specified.
Mechanical and plant rooms
Areas separated from the rest of the building, where the structure and the separation both carry requirements.
Exposed architectural steel
Where the steel is meant to be seen, a thin-film intumescent coating protects it without burying it in a thick grey cementitious layer.
Suitability
Where fireproofing does and does not belong
Every material on this site is the wrong answer somewhere. Knowing which side of this split your project sits on is worth more than any specification sheet.
A good fit when
- Projects with a written fire-protection specification to work to
- Structural steel that has been identified as requiring protection
- New construction, where access to the frame is still straightforward
- Work that can be sequenced before ceilings and services close the space in
Probably the wrong choice when
- Any request to make ordinary insulation "fireproof" — it is not, and we will not say it is
- Work with no specification, drawing or engineer behind it
- Situations needing a rating we cannot evidence for the complete assembly
- Asbestos-containing existing coatings, which need a qualified abatement contractor
If your project sits on the right-hand list, say so when you call and we will point you at the service that actually fits — including the cheaper one. Here is how this work relates to everything else we do.
Fireproofing sits apart from the rest of this site on purpose. It is not insulation, and insulation is not fire protection — spray polyurethane foam is a combustible plastic that needs a thermal barrier where it is left exposed, which is a requirement rather than an upgrade. Anyone describing foam as fireproof is either confused or hoping you are.
In practice we are on the same sites doing both. A distribution building may need protected steel and an insulated envelope, so the fire-protection package runs alongside batt work in the office fit-out and foam on the deck. Acoustic separation around plant rooms is a third, separate question, handled as sound-control work.
This is business-to-business work almost exclusively — warehouses and manufacturing facilities, offices, retail and mixed-use buildings, and packages tendered by general contractors. The employment lands around Concord and the industrial corridors of Brampton generate most of it. Send us the specification and the drawings and we will price what has actually been specified.
Before you commit
What this page will not tell you
Fireproofing is the most specification-driven work we do, and the most damaging place to guess. Some of the things a contractor could easily claim here are things we deliberately will not.
No ratings without the assembly
A fire-resistance rating belongs to a complete tested assembly, not to a product or a thickness in isolation. We do not quote a rating that has not been established for the assembly in front of us.
Insulation is not fire protection
Spray polyurethane foam is a combustible plastic and needs a thermal barrier where it is exposed. It is not fireproofing, and any contractor blurring the two is worth questioning.
Thickness is a specification, not a preference
Applied thickness comes from the design and the tested assembly. Spraying thinner to save material or thicker to look thorough both take the work outside what was tested.
Preparation decides adhesion
Mill scale, rust, oil, primer compatibility and surface temperature all govern whether the material stays on the steel. Most in-service failures start here rather than in the mix.
Also from NorthStar
Other services that come up alongside this one
Soundproofing
Acoustic treatment for walls, ceilings and mechanical rooms in homes, offices and multi-unit buildings, planned around how sound actually travels.
Spray Foam Insulation
Open-cell and closed-cell polyurethane foam that insulates and air seals in a single application. Used in attics, walls, basements, crawl spaces and commercial envelopes.
Blown-In Attic Insulation
Loose-fill fibreglass or cellulose blown across an attic floor to an even, measured depth. The usual choice for topping up an under-insulated attic.
Related services
Send us your fireproofing specification
Share the drawings, the schedule of members and the required ratings. We will review the scope and come back with a quote and any queries on the specification.