Xponexus Engineering

Roof Rafter Design

EN 1995-1-1 (EC5) roof rafter calculator with pitch angle, snow, wind uplift, dead load and combined bending+axial checks. Includes deflection, bearing and ridge/eaves thrust.

EN 1995-1-1EN 1991-1-3 Snow EN 1991-1-4 WindCombined N+M

Scope note:
Verifies EC5 §6 combined bending and compression/tension. Ridge thrust and eaves spread are indicative only. Confirm purlins, bracing and fire resistance separately.

Rafter Section & Material

Timber grade, section size and roof geometry.

Section

Timber grade Grade f_m,k (MPa) f_v,k (MPa) f_c,0,k (MPa) f_c,90,k (MPa) E_0,mean (MPa) E_0,05 (MPa)

Cross section & geometry Width b (mm) Depth h (mm) Rafter spacing s (mm) Rafter slope pitch α (°) Rafter span (horizontal) L_h (m) Rafter condition

Modification & service Service class Load duration (governing) k_mod (0=auto) γM k_def System factor k_sys

Roof Loads

Dead, snow, wind uplift (EN 1991). Per rafter based on spacing.

Loads

Dead & imposed Roof dead g_k (kN/m²) Ceiling dead g_k,ceil (kN/m²) Imposed (access) q_k (kN/m²) γG γQ

Snow (EN 1991-1-3) Ground snow s_k (kN/m²) Shape coeff μ₁ Exposure coeff C_e Thermal coeff C_t γQ,snow ψ0,snow

Wind (EN 1991-1-4) Wind pressure w_p (kN/m²) Cpe (roof zone) Cpi (internal) γQ,wind Bearing length l_b (mm) Design notes

Check Summary

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ULS + SLS

Bending (ULS)

—

Combined N+M

—

Shear (ULS)

—

Bearing

—

Wind uplift

—

Deflection

—

Governing: — Util ≥ 1.0 = FAIL

Detailed Report

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