
Cost = litres × price + application + inspection
Material quantity follows directly from area, thickness and volume solids:
Theoretical consumption (L) = Area (m²) × DFT (µm) ÷ (1000 × volume solids fraction). Practical consumption = theoretical ÷ (1 − loss).
Example: 1,000 m² at 1,000 µm DFT with 75 % volume solids needs 1,000 × 1,000 ÷ (1,000 × 0.75) ≈ 1,333 L theoretically; with 25 % application loss about 1,778 L.
The ten cost drivers
- Section factor of each member
- Fire rating
- Critical steel temperature
- Surface area
- Required DFT
- Volume solids of the product
- Application losses
- Surface preparation and primer
- Environment (drying, coats, topcoat)
- Inspection requirements
Value engineering levers
- Use the calculated critical temperature instead of a conservative default.
- Increase section size where it reduces the section factor of heavily coated members.
- Compare products – loading tables differ widely.
- Apply in the shop to reduce losses and site costs.
- Use boards or sprays where long ratings make coatings uneconomic.
FAQ
How much does intumescent coating cost per m²?
It depends on the DFT, which depends on the member and rating – the same product can cost several times more on a light beam than on a heavy column. Use the estimator with your rates or send the member schedule.
Preliminary calculations are provided for estimation purposes only. Final coating thickness and fire protection system selection must be verified against the approved product documentation, applicable project requirements and relevant engineering assessments.