GCP Monokote® MK-6 / Z-106 vs. Isolatek® Cafco® 300 / 400: 2026 Structural Fireproofing Spec & Cost Comparison (Ontario)
GCP Monokote® MK-6 / Z-106 vs. Isolatek® Cafco® 300 / 400: 2026 Ontario Overview & Code Essentials
For commercial general contractors, structural engineers, and Division 07 estimators bidding high-rise towers, underground parking garages, hospitals, and industrial warehouses across Toronto, Mississauga, Brampton, Vaughan, and Ontario, Division 07 81 00 (Applied Fireproofing) specifications almost always center on two industry titans: GCP Applied Technologies (formerly Grace) Monokote® MK-6® / Z-106 and Isolatek International Cafco® 300 / Cafco® 400. Understanding when these two cementitious fireproofing (SFRM) product lines are direct CAN/ULC-S101 equals—and when a 22 pcf Portland-cement formulation or a Turnkey 2 lb Closed-Cell SPF + 18-Mil DC315 Thermal Barrier Package is required—saves tens of thousands of dollars on commercial tenders while preventing municipal occupancy holds under Ontario Building Code Division B Part 3.
At Sprayfoam Solutions Toronto Inc., we operate as a Single-Source Certified Spray Foam & Fire Coating Contractor with dedicated continuous-mixer cementitious pump crews, intumescent structural steel coating teams, IFTI DC315 thermal barrier rigs, and Caliber Certified (CAN/ULC-S705.2 Licensed) Installers. Whether your architect specifies GCP Monokote® MK-6 / Z-106, Isolatek® Cafco® 300 / 400, Carboline®, International® Chartek® / Interchar®, Sherwin-Williams® Firetex® & other ULC-listed structural fireproofing systems, we deliver turnkey installation with full third-party ASTM E605 thickness/density and ASTM E736 cohesion/adhesion testing logs. Get a $250 Credit on Your Estimate — Check Your Price in 60 Seconds (/price-chat) • No Site Visit Required, or call (647) 333-3626.
Compare our 3 commercial B2B structural fireproofing and turnkey thermal barrier pricing tiers across the GTA & Ontario:
- 15 lb/ft³ Gypsum SFRM
- ASTM E736 ≥200 psf Bond
- Concealed Beams, Columns, OWSJ & Fluted Floor Decks
- Includes $250 Estimate Credit
- 22 lb/ft³ Portland-Cement SFRM
- ASTM E736 ≥430 psf Bond
- Underground Parkades, Mechanical Rooms, Elevator Shafts & Unconditioned Bays
- Pairs With Structural SFRM on Warehouse Roof/Wall Decks
- CAN/ULC-S705.1 + CAN/ULC-S124 (CCMC #14036-R)
- Single-Source GC Subcontract
2026 Monokote MK-6 / Z-106 vs. Cafco 300 / 400 Cost Per Sq Ft & Technical Spec Comparison (Ontario)
In 2026, cementitious fireproofing cost in Ontario is driven primarily by dry density (15 pcf vs. 22 pcf vs. 40 pcf), required fire-resistance rating (45 min, 1 hr, 2 hr, 3 hr, or 4 hr under CAN/ULC-S101), and the steel section factor (W/D or M/D ratio). Across Toronto and the GTA, GCP Monokote® MK-6® HY and Isolatek® Cafco® 300 are priced competitively within 3% to 5% of each other as standard 15 pcf commercial gypsum systems, while Monokote® Z-106 and Cafco® 400 represent the matched 22 pcf medium-density Portland-cement tier:
| Structural Fireproofing System | Dry Density & Binder Chemistry | ASTM E736 Bond Strength | 2026 Ontario Installed Cost (/sq ft) | Approved OBC / CAN/ULC-S101 Application |
|---|---|---|---|---|
GCP Monokote® MK-6® HY / MK-6s | 15 pcf (240 kg/m³) Gypsum-Based SFRM | ≥ 200 psf ( 9.6 kPa) | $2.75 – $5.25 / sq ft(1–2 Hr Steel) | Concealed interior structural steel, beams, columns & floor decks |
Isolatek® Cafco® 300 / 300 HS | 15 pcf (240 kg/m³) Gypsum-Based SFRM | ≥ 200 – 295 psf ( 9.6–14.1 kPa) | $2.75 – $5.50 / sq ft(1–2 Hr Steel) | Direct ULC equivalent to MK-6 for interior conditioned frames |
GCP Monokote® Z-106 / Z-106 HY | 22 pcf (352 kg/m³) Portland-Cement SFRM | ≥ 434 psf ( 20.8 kPa) | $4.50 – $8.25 / sq ft(1–3 Hr Steel) | Exposed parkades, loading docks, mech rooms & high-humidity zones |
Isolatek® Cafco® 400 / 400 AC | 22 pcf (352 kg/m³) Portland-Cement SFRM | ≥ 434 psf ( 20.8 kPa) | $4.50 – $8.25 / sq ft(1–3 Hr Steel) | Direct ULC equivalent to Z-106 for moisture/abrasion zones |
High-Density Monokote® Z-146 / Cafco® Fendolite® | 40+ pcf (640 kg/m³) High-Impact Portland | ≥ 1,000+ psf ( 47.9 kPa) | $8.50 – $14.50 / sq ft(2–4 Hr Steel) | Industrial petrochemical, high-impact & exterior structural steel |
2026 Worked Commercial Division 07 Bids: Concealed Office Deck vs. Exposed Parkade vs. Turnkey Warehouse
Because Division 07 fireproofing bids scale with total developed square footage of steel (flange + web perimeter) and scissor-lift staging height, here is how 15 pcf Monokote® MK-6® / Cafco® 300, 22 pcf Monokote® Z-106 / Cafco® 400, and our Turnkey 2 lb SPF + 18-Mil DC315 package compare across three real-world 2026 Ontario commercial projects:
| Worked Ontario Commercial Project | Developed Surface Area | Specified ULC Assembly & Density | 2026 Installed Rate (/sq ft) | Total Turnkey Subcontract |
|---|---|---|---|---|
Mid-Rise Commercial Office Floor Deck & Beams(Toronto / Markham) | 12,000 sq ft concealed steel deck & W-beams( 1-Hr ULC) | 15 pcf GCP Monokote® MK-6® HY or Isolatek® Cafco® 300 ( ~3/4" avg per W/D) | $2.95 – $4.25 / sq ft | $35,400 – $51,000(Includes ASTM E605 pin logs) |
Underground P1 Condo Parkade & Loading Bay(Mississauga / Vaughan) | 8,500 sq ft exposed transfer beams & columns( 2-Hr ULC) | 22 pcf Monokote® Z-106 or Cafco® 400 Portland SFRM( ≥434 psf bond) | $5.25 – $7.60 / sq ft | $44,625 – $64,600(Moisture & exhaust abrasion rated) |
Hybrid Industrial Distribution Warehouse(Brampton / Milton) | 15,000 sq ft roof/walls ( SPF + DC315) + 3,000 sq ft steel columns(SFRM) | Turnkey 3.0" 2 lb SPF + 18-Mil DC315 + 1-Hr 22 pcf SFRM on columns | $4.60 – $6.40 / sq ft(Blended) | $82,800 – $115,200(Single-source saves $18k+) |
![Clear Sansin Firestop 99 intumescent fire coating applied to high-quality pressurized mass timber walls and ceilings in Etobicoke, Toronto (The Kingsway) [JOB-2026-07-24-01]](/images/jobs/intumescent-fire-coating/intumescent-fire-coating-toronto-job-2026-07-24-01-22.webp)
Head-to-Head Engineering Breakdown: 15 PCF Gypsum (MK-6 vs. Cafco 300) vs. 22 PCF Portland (Z-106 vs. Cafco 400)
When reviewing Division 07 specifications or preparing an architect substitution request on an Ontario commercial tender, estimators and site superintendents need to know the exact physical and chemical differences between 15 pcf gypsum-based SFRM and 22 pcf Portland-cement SFRM (see our Ontario cementitious fireproofing engineering guide):
- 1. Binder Chemistry & Moisture Resistance (Gypsum vs. Portland Cement): Both Monokote® MK-6® and Cafco® 300 use a calcined gypsum (calcium sulfate hemihydrate) binder blended with expanded vermiculite or polystyrene/cellulose aggregate. While highly economical for dry, conditioned interior plenums, gypsum softens if subjected to repeated freeze-thaw cycling, roof leaks, or relative humidity constantly above
85%. By contrast, Monokote® Z-106 and Cafco® 400 use a hydraulic Portland-cement binder (22 pcf), which cures into a hard, moisture-resistant matrix ideal for unenclosed construction phases, underground parking garages, and mechanical penthouses. - 2. Cohesive/Adhesive Bond Strength (
ASTM E736— 200 psf vs. 434+ psf): Standard15 pcfMK-6 and Cafco 300 are rated for a minimum200 psfbond strength (295 psfon Cafco 300 HS), suitable behind acoustic drop ceilings or drywall shafts. Whenever structural steel remains exposed to elevator-shaft air velocity (>1,000 fpm), forklift traffic vibration, or HVAC air-handling plenums, architects mandate22 pcfMonokote® Z-106 or Cafco® 400 for their >434 psf (20.8 kPa) bond strength. - 3. Yield, Pumpability & Thickness per Pass (
W/DSection Factor Math): Under National Research Council Canada / ULC CAN/ULC-S101 fire-resistance directories, required spray thickness (3/8"to2-1/4") is calculated from the steel member’sW/Dratio (weight per foot divided by heated perimeter). Cafco® 300 frequently offers slightly higher theoretical board-foot yield per bag, whereas Monokote® MK-6® HY (High Yield) paired with GCP’s Yield-Pro injection system allows rapid high-build single passes with minimal rebound. - 4. Galvanized Deck & Primed Steel Adhesion (
ULC Primed Beam Criteria): Neither Monokote nor Cafco can be sprayed arbitrarily over slick alkyd shop primers or oily galvanized steel flutes without verifying the specific ULC Design listing (F900,D900,Z100,I500series). On heavy structural sections (W/Dlimits) or incompatible shop primers, our crew applies Monokote® Spatterkote® SK-3 or Cafco® Bond-Seal adhesive tie-coat (or mechanical metal lath where mandated by ULC) to guarantee zero delamination. - 5. Cold-Weather Ontario Pumping & Temporary Enclosure Rules (
≥4.4°C / 40°F): Both GCP and Isolatek mandate a minimum steel substrate and ambient air temperature of 4.4°C (40°F) for 24 hours prior to, during, and for 24 hours after SFRM application, along with positive ventilation to exhaust evaporating mix water. - 6. Air Erosion Resistance in High-Velocity HVAC Plenums (
ASTM E859): Both systems passASTM E859air erosion testing at0.00 g/ft²dust loss when properly cured, preventing loose mineral or gypsum fibres from entering hospital, school, or office building air-handling return plenums.
How W/D (M/D) Steel Section Factor Math Controls Your Monokote or Cafco Thickness & Bag Count
Estimators who bid structural fireproofing using a flat thickness assumption (e.g., guessing 3/4" everywhere) routinely misprice commercial tenders by 25% to 40%. A lightweight W200x27 beam or open-web steel joist heats up rapidly in a fire (low W/D ratio ≈ 0.45–0.65) and requires 1-1/8" to 1-9/16" of Monokote® MK-6® or Cafco® 300 for a 2-hour rating, whereas a massive W360x196 transfer girder (high W/D ratio > 1.8) acts as a heat sink and may require only 7/16" to 5/8". Our estimating desk runs a member-by-member W/D takeoff from your structural steel schedule.
ULC Design Equivalency & Ontario Building Code Section 3.1.7 Compliance (CAN/ULC-S101 vs. CAN/ULC-S124)
One of the costliest mistakes on commercial industrial projects is confusing CAN/ULC-S101 structural steel fire-resistance ratings with CAN/ULC-S124 thermal barriers over spray foam (which we break down in Structural Steel Fire Rating Rules in Ontario and Intumescent vs. Cementitious Fireproofing). Many modern Ontario warehouses and mixed-use buildings require both systems on the same jobsite:
![Caliber Certified installer in white protective coveralls spraying 3.5" (R22) of 2lb closed-cell spray foam across exterior 2x6 wood stud cavities in Scarborough, Toronto (Guildwood & Birch Cliff) [JOB-2023-07-22-01]](/images/jobs/closed-cell-spray-foam/closed-cell-spray-foam-toronto-job-2023-07-22-01-29.webp)
Why General Contractors Bundle Structural Fireproofing + Turnkey 2 lb SPF & 18-Mil DC315 Under One Subcontract
On commercial warehouses, cold-storage plants, podium retail plazas, and underground parkades across the GTA, primary steel columns and floor-ceiling assemblies often require 1-hour or 2-hour cementitious fireproofing (Monokote MK-6 / Z-106 or Cafco 300 / 400), while the exterior metal walls, soffits, and roof deck require thermal insulation plus a 15-minute thermal barrier. By awarding both scopes—including our Turnkey 2 lb Closed-Cell SPF + 18-Mil DC315 Thermal Barrier Package (see our 2026 Turnkey Warehouse SPF + DC315 Cost Guide)—to Sprayfoam Solutions Toronto Inc. through our General Contractor Bid Desk, you eliminate split lift rentals, duplicate poly masking, and trade-sequencing clashes where foam is accidentally sprayed over uninspected steel before the ASTM E605 fireproofing inspector signs off.
Lowest cost per sq ft for concealed 1–2 hr structural steel.
Pumped via continuous mixer onto clean/primed steel & deck.
Standard choice for office towers, schools & concealed plenums.
When structural steel beams, open-web joists, and fluted metal floor decks will be concealed behind suspended acoustic ceilings or drywall, 15 pcf GCP Monokote MK-6 HY or Isolatek Cafco 300 delivers the most economical 1-hour to 3-hour CAN/ULC-S101 fire-resistance rating in Ontario.
![5" (R31) of 2lb closed-cell spray foam on a sloped cathedral ceiling roof deck in Toronto (Forest Hill & Rosedale) [JOB-2025-07-17-01]](/images/jobs/cathedral-ceiling-spray-foam/cathedral-ceiling-spray-foam-toronto-job-2025-07-17-01-6.webp)
Same-Week Commercial Fireproofing & Turnkey Spray Foam Dispatch Across Toronto & Ontario
Every commercial structural fireproofing and building envelope project is executed by Sprayfoam Solutions Toronto Inc. with $0 surrounding GTA travel fee across Toronto, Mississauga, Brampton, Vaughan, Markham, Oakville, Burlington, Hamilton, Oshawa, and Barrie:
Get a 60-second ballpark at /price-chat or send structural steel schedules for an exact ULC Design thickness takeoff.
We verify MEP hangers are installed, check primer compatibility, apply Spatterkote/Bond-Seal if required, and mask.
Precision application of 15/22 pcf SFRM to exact W/D thickness, followed by any turnkey 2 lb SPF + 18-mil DC315 scope.
Pin-gauge thickness checks, density cup logs, cleanup, and delivery of your signed ULC & CCMC compliance binder.
Frequently Asked Questions
In 2026, standard-density 15 pcf gypsum cementitious fireproofing (GCP Monokote® MK-6® HY or Isolatek® Cafco® 300) costs $2.75 to $5.50 per square foot installed in Toronto and Ontario for a 1-hour to 2-hour CAN/ULC-S101 structural rating. Medium-density 22 pcf Portland-cement fireproofing (Monokote® Z-106 or Cafco® 400) costs $4.50 to $8.25 per sq ft. Call Sprayfoam Solutions Toronto Inc. at (647) 333-3626 or check your price in 60 seconds at spfsolutions.ca/price-chat.
Yes. For concealed interior structural steel columns, beams, open-web steel joists, and fluted metal floor decks, GCP Monokote® MK-6® HY and Isolatek® Cafco® 300 are universally recognized across Ontario Division 07 81 00 specifications as 15 pcf standard-density gypsum SFRM equivalents tested to CAN/ULC-S101 (ULC Design Z100, F900, D900, and I500 series). Similarly, Monokote® Z-106 and Cafco® 400 are direct 22 pcf medium-density Portland-cement equivalents.
Whenever structural steel is located in an unconditioned, high-humidity, freeze-thaw, or mechanically exposed environment—such as underground parking garages, open loading docks, mechanical penthouses, elevator shafts (air velocity >1,000 fpm), or warehouses without suspended ceilings—15 pcf gypsum SFRM can absorb moisture or abrade. Specifying 22 pcf Portland-cement Monokote® Z-106 or Cafco® 400 provides hydraulic moisture resistance and over double the ASTM E736 bond strength (≥434 psf vs. 200 psf).
Under CAN/ULC-S101, cementitious fireproofing thickness is never a single flat number across all steel sizes. It is determined by the specific ULC Design Number, the required hourly rating (45 min to 4 hr), whether the assembly is restrained or unrestrained, and each steel member’s W/D (or M/D) section factor (weight per linear foot divided by the heated perimeter inches). Heavier wide-flange columns with high thermal mass require thinner SFRM (e.g., 7/16" to 3/4"), while lightweight open-web steel joists require thicker passes (1-1/8" to 1-3/4"+).
Our commercial Division 07 and Caliber Certified (CAN/ULC-S705.2 Licensed) Installers apply GCP Monokote® MK-6 / Z-106, Isolatek® Cafco® 300 / 400, Carboline®, International® Chartek® / Interchar®, Sherwin-Williams® Firetex® & other ULC-listed structural fireproofing systems, alongside IFTI DC315® (CCMC #14036-R), No-Burn® Plus ThB, Flame Control No. 60-60A & other approved CAN/ULC-S124 thermal barrier coatings over BASF Walltite® Eco v.3, Huntsman Building Solutions (Icynene/Demilec), Johns Manville & other approved CCMC spray foam chemicals — Low-VOC HFO Blown.
Sequencing is critical on hybrid assemblies. Cementitious SFRM (Monokote / Cafco) must never be sprayed over polyurethane foam, and spray foam must never encapsulate a structural steel beam before the third-party testing engineer completes ASTM E605 thickness/density verification on the rated steel. When a warehouse or parkade ceiling requires both structural fireproofing and thermal insulation, our single-source crew coordinates the exact ULC-approved sequence and Turnkey 2 lb Closed-Cell SPF + 18-Mil DC315 Package.
On Ontario Part 3 commercial projects, the owner’s third-party materials testing engineer performs ASTM E605 thickness checks (using a calibrated pin depth gauge across web, flange, and flute points) and core-cup dry density sampling (≥15.0 pcf average for MK-6/Cafco 300; ≥22.0 pcf for Z-106/Cafco 400), plus ASTM E736 field cohesion/adhesion pull tests. Our crew pre-verifies every bay before calling for inspection.
General contractors, estimators, and property owners can claim a $250 Credit on Your Estimate and check ballpark square-foot pricing in 60 seconds at spfsolutions.ca/price-chat (No Site Visit Required), upload structural drawings via our General Contractor Bid Desk, or call Sprayfoam Solutions Toronto Inc. at (647) 333-3626.
Select your Division 07 service hub or local GTA municipality below for 2026 unit pricing and same-week commercial rig dispatch:
