EN 14015 Roof Design Calculator

Membrane roof plate thickness (pressure and buckling controlled) for self-supporting cone and dome roofs (BS EN 14015:2004, §10.2–10.4)

◉ BS EN 14015:2004 §10.2–10.4 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL

⚠ Indicative tool only, and structurally distinct from the existing API 650 and IS 803 Roof Design calculators. EN 14015 splits membrane roof thickness into two independent checks — pressure resistance and buckling resistance — and takes the greater; neither API 650's nor IS 803's roof formulas work this way. Verified directly against this edition's page images; sanity-checked with realistic inputs, buckling governs overwhelmingly at typical low design pressures (a few mbar), consistent with how thin roof plates actually behave.

Identification

Company

Tank ID

Location

Record Type

Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.

Roof Type & Slope Defaults (§10.2, reference)

One of two roof types shall be specified: (a) self-supporting cone or dome, with or without a supporting structure; or (b) column-supported. Default slopes/radii unless otherwise specified: self-supporting cone — 1 in 5; dome — radius of curvature between 0.8× and 1.5× tank diameter; column-supported roof — 1 in 16.

Minimum Thickness & Joint Efficiency (§10.3.3–10.3.6)

Joint Type

Specified Minimum Yield Strength N/mm²

Minimum roof plate and structural member thickness (excluding corrosion allowance): 5mm for carbon/carbon-manganese steel, 3mm for stainless steel. Lap joints require ≥25mm minimum overlap. Allowable design stress S = 2/3 × yield.

Result

Joint efficiency J used—

Allowable design stress S—

Membrane Roof Plate Thickness (§10.4.2, Eq.12–14)

Roof Shape

R — Roof Radius / Curvature m

p — Design Pressure (Table 3) mbar

R₁ = R directly for spherical roofs, or R/sinθ for conical roofs. Pressure-controlled: e_p=pR₁/(20SJ) [spherical] or pR₁/(10SJ) [conical].

Result

R₁ — radius of curvature used—

Pressure-controlled thickness—

Membrane Roof Plate Thickness — Buckling (§10.4.2, Eq.14)

p_e — External Loads + Self Weight + Internal Vacuum kN/m²

E — Young's Modulus N/mm²

e_p = 40 × R₁ × √(10p_e/E). Uses R₁ from the card above.

Result

Buckling-controlled thickness—

Minimum table thickness (§10.3.3, excl. CA)—

Governing thickness (greatest of the three)—

Roof Framing Bracing (§10.3.7, reference)

Cross bracing in the plane of the roof surface: at least 2 bays (between two pairs of adjacent rafters), spaced evenly around the circumference, on all roofs exceeding 15m diameter. Additional vertical ring bracing on trussed roofs: one ring for roofs over 15m up to and including 25m diameter; two rings for roofs over 25m diameter.

Save & Report