Types of Structural Loads
Structures must resist permanent self-weight (dead loads) and variable loads from occupancy and environment (live, wind, snow loads). Design uses factored combinations for safety.
Dead Loads (Permanent)
Concrete slab (150mm): 3.6 kN/m²
Timber floor + finish: 1.0-1.5 kN/m²
Steel deck + concrete: 2.5-3.5 kN/m²
Roof (flat, membrane): 0.5-1.0 kN/m²Live Loads (Variable, by occupancy)
Residential: 1.5-2.0 kN/m²
Office: 2.5-3.0 kN/m²
Retail/shop: 4.0-5.0 kN/m²
Storage: 7.5+ kN/m²
Stairs: 3.0-4.0 kN/m²Factored Load Combinations (Eurocode/LRFD)
Ultimate: 1.35×DL + 1.5×LL (design strength check)
Service: 1.0×DL + 1.0×LL (deflection check)
Example: office floor
DL = 2.5 kN/m², LL = 3.0 kN/m²
Design load = 1.35×2.5 + 1.5×3.0 = 3.375 + 4.5 = 7.875 kN/m²Key Conversion
- 1 kN/m² = 20.9 psf (pounds per square foot)
- 1 psf = 47.9 Pa
- 1 kN = 0.2248 kip (US)
Calculate structural loads: Free Structural Load Calculator