Floor and Roof Diaphragm Action

About This Reference

Diaphragm action in steel buildings. Deck-to-beam connections, chord forces, collector design, and lateral load path through floor and roof systems.

Consult this reference for design values, tables, and code provisions related to floor and roof diaphragm action.

How to Use This Reference

Find the value, table, or provision you need below.
Cross-reference against your project specification and the applicable code edition.
Where this reference covers multiple design codes, select the tab or section matching your jurisdiction.

Design Code Coverage

This reference page covers provisions relevant to one or more of the following standards:

AISC 360 — Steel Construction Manual, 15th Edition (LRFD & ASD).
AS 4100:2020 — Steel Structures (limit state design).
EN 1993-1-1 / 1-8 — Eurocode 3, General rules and connection design.
CSA S16:2019 — Design of Steel Structures (limit states design).

Important Notes

Values shown are for quick reference only and must be verified against the source standard.
Material certifications (Mill Test Reports) take precedence over tabulated minimums.
Always confirm the applicable edition of the code for your project jurisdiction.

Page last updated: 2026-03-15. All calculations and reference values must be verified by a qualified engineer before use in design.

Free Online Steel Calculator for Structural Design

Steel Calculator is a free online structural steel design calculator supporting AISC 360, AS 4100, EN 1993, and CSA S16. Design bolted connections, welded connections, base plates, steel beams, and steel columns with full step-by-step derivations. All calculations run instantly in your browser via WebAssembly.

Steel Connection Calculators

Bolt Calculator -- Shear, bearing, and block shear checks for bolted connections
Weld Calculator -- Fillet weld capacity and stress analysis
Base Plate Calculator -- Bearing, bending, and anchor bolt design
Gusset Plate Calculator -- Whitmore section, block shear, buckling checks
Splice Connection Calculator -- Flange and web splice design
Anchor Bolt Calculator -- Embedment and pullout capacity

Structural Analysis Tools

Simple Beam Calculator -- Reactions, SFD, BMD, and deflection for simply supported beams
Portal Frame Calculator -- 2D frame analysis with SFD/BMD diagrams and load combinations
Steel Beam Capacity -- Flexure, shear, and lateral-torsional buckling checks
Steel Column Capacity -- Axial compression and buckling analysis
Beam Deflection Calculator -- Deflection limit checks (L/360, L/240)
Beam Span Table -- Maximum span tables for common sections
Concrete Footing Reference -- Bearing, one-way shear, and punching shear checks

Engineering Tools

Moment of Inertia Calculator -- Second moment of area for composite shapes
Bolt Torque Calculator -- Tightening torque and preload estimation
Mohr's Circle Calculator -- Principal stresses and maximum shear stress
Wind Load Calculator -- Wind pressure per ASCE 7 and AS/NZS 1170.2
Weld Symbol Generator -- Interactive AWS A2.4 weld symbol builder
Steel Weight Calculator -- Weight per length for standard steel sections
Unit Converter -- Structural engineering unit conversions (kN/kips, MPa/ksi, mm/in)

Reference Tables

Section Properties Database -- AISC W-shapes, UB, UC, IPE, HEA, HEB sections
Steel Beam Sizes -- Complete dimensional tables for standard beams
Steel Grades -- Yield and tensile strength for ASTM, AS/NZS, EN, CSA grades
K-Factor Chart -- Effective length factors for column buckling
Bolt Hole Sizes -- Standard, oversize, and slotted hole dimensions
Minimum Weld Size -- AISC Table J2.4 minimum fillet weld sizes
Rebar Reference -- Bar sizes, areas, and spacing tables

Design Codes Supported

AISC 360-22 -- American Institute of Steel Construction (USA)
AS 4100-2020 -- Steel Structures (Australia/NZ)
EN 1993-1-8 -- Eurocode 3 Connections (Europe)
CSA S16-19 -- Design of Steel Structures (Canada)

All calculations are for preliminary estimation only and must be verified by a qualified Professional Engineer (PE/SE). Steel Calculator is not a substitute for professional engineering judgment. Use at your own risk.