Fire Engineering & Eurocode Compliance in Volumetric Steel Modular Buildings
Structural fire resistance (R30 to R120), horizontal and vertical intumescent cavity barriers between modules, dry riser integration, and EN 1993-1-2 structural calculations.
1. Structural Steel Fire Protection: Board Encasing vs. Intumescent Coatings
Bare structural steel loses approximately 50% of its yield strength at temperatures around 550°C, a threshold easily reached within 10 to 15 minutes in a standard flashover compartment fire. In multi-storey modular buildings, load-bearing corner columns and ceiling beams must withstand fire exposure for 30, 60, 90, or 120 minutes (R30 to R120) without buckling.
SERMODULA implements factory-controlled passive fire protection engineered to EN 1993-1-2 hot structural design standards. Steel hollow sections are encased within certified multi-layer Type DF gypsum and calcium silicate boards fitted flush within wall assemblies, eliminating site-applied mess. In technical risers and high-load transfer grillages, thin-film intumescent coatings provide clean, factory-certified fire resistance without sacrificing interior millimeter clearances.
2. Horizontal and Vertical Cavity Barriers in Inter-Module Voids
The assembly of 3D volumetric modules creates intentional 20 to 50 mm acoustic and structural clearance voids horizontally between adjacent dwellings and vertically between stacked storeys. If left unsealed, these concealed spaces can act as deadly chimneys, drafting superheated gas, smoke, and flames rapidly across the entire edifice.
SERMODULA addresses this via factory-installed intelligent cavity barriers. Mineral wool cores wrapped in durable reinforced foil are fitted with graphite-based intumescent mastic facings. Under normal conditions, they maintain continuous acoustic and thermal decoupling. When exposed to heat above 180°C, the intumescent facing rapidly expands by up to 25 times its original volume, hermetically choking the gap, halting smoke transit, and providing certified EI 60 to EI 120 compartmentation integrity.
3. Pre-Installed Dry Risers, Sprinkler Networks & Certified Penetration Seals
Penetrations through floors and compartment walls for ventilation ducts, drainage pipes, and power cables represent the most vulnerable points for fire propagation in multi-unit buildings. Site-drilled holes often violate fire codes due to poor local sealing.
SERMODULA pre-installs all vertical risers inside factory-fabricated fire-rated utility ducts. High-tensile PVC-U and soundproof PP soil stacks are fitted with certified intumescent pipe collars (EI 120) that crush plastic pipes closed as they melt. In buildings exceeding 4 storeys, stainless steel dry risers with landing valves and pre-piped concealed sprinkler networks are pressure-tested and wired in the factory, minimizing hazardous site welding.
4. Eurocode EN 1993-1-2 Structural Calculations & As-Built Certification
European municipal building authorities require rigorous structural verification proving that a building will not collapse prematurely during evacuation. For steel construction, Eurocode EN 1993-1-2 governs structural fire design via advanced finite element thermal-mechanical calculations.
Every SERMODULA multi-storey modular project is accompanied by a full Eurocode structural fire engineering report. Column critical temperatures (Theta_cr), section factors (Am/V), and fire load densities are mathematically proven. Upon final delivery, an exhaustive As-Built Fire Safety Pack containing manufacturer batch certificates, third-party laboratory test reports, and photographic installation logs is handed over directly to municipal building control.
Structural Fire Protection & Compartmentation Standards by Building Height
1 – 2 Storeys (Low-Rise)
3 – 4 Storeys (Medium-Rise)
5 – 6 Storeys (Multi-Storey)
| Building Height / Storeys | Structural Column Rating (R) | Inter-Module Cavity Barrier (EI) | Active Fire Systems | Standard Internal Lining |
|---|---|---|---|---|
| 1 – 2 Storeys (Low-Rise) | R30 – R60 | EI 30 – EI 60 | Smoke detection + fire extinguishers | Type A/F Gypsum plasterboard (Class A2-s1,d0) |
| 3 – 4 Storeys (Medium-Rise) | R60 – R90 | EI 60 – EI 90 | Dry riser provision + alarm sounders | Dual Type DF boards + intumescent perimeter seals |
| 5 – 6 Storeys (Multi-Storey) | R90 – R120 | EI 90 – EI 120 | Pressurized dry risers + sprinkler option | Multi-layer calcium silicate + intumescent coatings |
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