Advisory Desk Notes

Advisory Desk or AD Notes reflect recent developments in technical standards or new knowledge that designers need to be made aware of. Some of them arise because a question is being frequently asked of the steel sector’s technical advisers. They have always been recognised as essential reading for all involved in the design of constructional steelwork. Published by the SCI in NSC magazine, they are brought together here for your reference.

• AD 552: Errata in P362 - Steel building design; concise Eurocodes, February 2026
• AD 550: Stiffness classification for welded beam to column joints, November 2025
• AD 549: Steel decking and composite slab span types, October 2025
• AD 548: High shear regions for large web openings as defined in SCI P355, September 2025
• AD 546: Critical temperatures for compression members in the UK NA to BS EN 1993-1-2, July 2025
• AD 544: Washers for preloaded bolting assemblies, June 2025
• AD 543: Deflection of composite slabs, May 2025
• AD 542: Design buckling resistance of angle sections, April 2025
• AD 541: Imposed roof loads in combination with PV, April 2025
• AD 540: Vertical shear resistance of composite slabs and anchorage, March 2025
• AD 539: Locking devices for fasteners subject to vibration, March 2025
• AD 538: Provision of Information - Joint Forces, January 2025
• AD 537: Web resistance, February 2025
• AD 536: In-plane member buckling lengths for portal frames, January 2025
• AD 535: Horizontal lateral loading on internal load-bearing walls in residential buildings, November 2024
• AD 534: Anchorage length of horizontal stiffeners in steel and composite beams with large web openings, October 2024
• AD 533: Floors Subjected to Rhythmic Activities, September 2024
• AD 532: Integral bracing and diaphragm action of light steel framed walls, September 2024
• AD 531: Heavy power floats on composite slabs during construction, July 2024
• AD 530: Countersunk head bolts, June 2024
• AD 528: Lateral restraint forces for beams, May 2024
• AD 527: Hybrid connections with bolts and welds, April 2024
• AD 526: Composite beams subject to axial force and bending, March 2024
• AD 525: Fire resistance of weathering steel, March 2024
• AD 524: Composite slabs and minimum reinforcement limits, March 2024
• AD 523: Slip factor of galvanised steel for non-slip joints, January 2024
• AD 522: Washers for slotted and oversized holes, December 2023
• AD 521: Restraint by precast concrete slabs with symmetrical loading, November 2023
• AD 520: Amendment to Table 8 in the MPS-Bolts (issue 14), February 2024
• AD 519: Equivalent horizontal forces and combinations of actions, January 2024
• AD 518: Classification of sections at elevated temperature, October 2023
• AD 517: Heavy concentrated loads on composite slabs, November 2023
• AD 516: Publication of second-generation Eurocodes, September 2023
• AD 515: Welding of structural nuts and bolts, October 2023
• AD 514: Straightness criteria for structural members, August 2023
• AD 513: Plastic modulus of Tee sections, July 2023
• AD 512: Eurocode requirements for wind bracing connections, September 2023
• AD 511: Shear studs on non-composite edge beams with composite slabs, July 2023
• AD 510: P281 worked example of beams curved on plan, July 2023
• AD 509: Non-slip connections in wind bracing, June 2023
• AD 508: Wind load on roofs of multispan portal frame buildings, May 2023
• AD 507: Galvanizing steel of grade S460M, May 2023
• AD 506: Effective length of equivalent T-stubs, April 2023
• AD 505: Bolts in 3 to 4 mm thick steel, April 2023
• AD 504: Web to flange welds in box sections subject to bending and torsion, April 2023
• AD 503: Design of struts for self-weight bending, February 2023
• AD 502: Design to BS 5950 and other standards, March 2023
• AD 501: Pre-loadable bolting assemblies, January 2023
• AD 500: Tolerance at cantilever tips, February 2023
• AD 499: Thermal expansion in car parks, December 2022
• AD 498: Modelling composite floors for vibration, November 2022
• AD 497: NHSS 20 - SHW Series 1800 Certification Requirements, January 2023
• AD 496: Toughness testing of bolts, November 2022
• AD 495: Resistance of shear studs in trapezoidal decking with transverse ribs, October 2022
• AD 494: Practical slenderness limits for compression members, September 2022
• AD 493: Steel grade based on tested samples, October 2022
• AD 492: Effective length of valley columns out of the plane of a portal frame, August 2022
• AD 491: Hydrogen embrittlement in structural bolting assemblies - effects and remedies, September 2022
• AD 490: Vibration response: root-mean-quad acceleration, July 2022
• AD 489: Height of shear studs, July 2022
• AD 488: Thickness of Galvanizing, June 2022
• AD 487: Correction to EN 1993-1-3, May 2022
• AD 486: NSSS Annex J amendment, June 2022
• AD 485: Continuity of additional bar reinforcement for fire in composite floors, April 2022
• AD 484: Snow design situations, May 2022
• AD 483: Correction to SCI P406 (Determining design displacements for bridge movement bearings), March 2022
• AD 482: Responsibilities for reinforcement design and detailing in composite slabs and beams, March 2022
• AD 481: Composite beams with deep composite slabs, April 2022
• AD 480: Correction to P399 Appendix F Worked Example, March 2022
• AD 479: Design moments in equations 6.61 and 6.62 of BS EN 1993-1-1, January 2022
• AD 478: Effective length of T-stubs Corrections to BS EN 1993-1-8 and P398, December 2021
• AD 477: Transverse bending of composite slabs subjected to point loads, February 2022
• AD 476: Design of a parallel flange channel for axial compression and bending, November 2021
• AD 475: Buckling of cruciform columns, January 2022
• AD 474: Elastic critical moment for lateral torsional buckling using design software, October 2021
• AD 473: Holes in beams for temporary lifting attachments, November 2021
• AD 472: Design loads for splices in columns continuous through transfer structures, November 2021
• AD 471: Second order moments for splice design, June 2022
• AD 470: Moments due to eccentricity at a column splice, August 2021
• AD 469: P385 Design of Steel Beams in Torsion - Error in Example 3, October 2021
• AD 468: Error in P359 formula for shrinkage-induced deflection of a composite slab, October 2021
• AD 467: Use of washers in single bolt lap joints, June 2021
• AD 466: Probability factors applied to characteristic wind and snow loads for non-standard return periods, September 2021
• AD 465: Amendment to clauses on negative tolerances on cambers in the National Structural Steelwork Specification, July 2021
• AD 464: Clarification of the reference strain rate in EN 1993-1-10, April 2021
• AD 463: Corrections to BS 5950-5:1998, June 2021
• AD 462: Buckling length of compression members in cross bracing, March 2021
• AD 461: Anchorage of bars in the troughs of composite slabs, May 2021
• AD 460: Amendment A2 to EN 1993-1-4, April 2021
• AD 459: Shear resistance of stainless steel fixings, February 2021
• AD 458: Web panel shear resistance, February 2021
• AD 457: ‘Bimoment’ in Eurocode design, December 2020
• AD 456: Impact forces on car parks, December 2020
• AD 455: Design resistances for bespoke components in P358 (Green Book), January 2021
• AD 454: Design checks for Category B preloaded assemblies, November 2020
• AD 453: Accumulated deviations in erected steelwork, November 2020
• AD 452: Errata in P385: Design of steel beams in torsion, October 2020
• AD 451: Welding of reinforcement to cast-in plates, October 2020
• AD 450: Resistance of composite slabs to concentrated loads, October 2020
• AD 449: Elastic critical load factor, α_cr, September 2020
• AD 448: Support to profiled steel decking, September 2020
• AD 447: Openings in composite slabs, July 2020
• AD 446: P397 Elastic design of single span steel portal frame buildings to Eurocode 3, July 2020
• AD 445: Corrosion protection of steel and composite bridges, July 2020
• AD 444: Designing for access to facilitate cost effective operation and maintenance of steel bridges, June 2020
• AD 443: The use of fully threaded bolts, June 2020
• AD 442: Designing to facilitate cost effective operation and maintenance of steel and composite bridges, May 2020
• AD 441: Minimum degree of shear connection in composite beams, May 2020
• AD 440: Fire design of external steelwork, May 2020
• AD 439: Transverse reinforcement in composite beams, April 2020
• AD 438: Non-slip connections to BS 5950, March 2020
• AD 437: Curtailment of transverse bar reinforcement in composite beams with steel decking designed using Eurocodes, February 2020
• AD 436: Section classification of a flat plate, January 2020
• AD 435: Beams supporting precast planks: checks in the temporary condition, November 2019
• AD 434: Validity rules for hollow section joints, October 2019
• AD 433: Dynamic modulus of concrete for floor vibration analysis, September 2019
• AD 432: Wind loads on building canopies, July 2019
• AD 431: Column web panel strengthening, June 2019
• AD 430: Wind load on unclad frames, May 2019
• AD 429: Slip factors for alkali-zinc silicate paint, April 2019
• AD 428A: Lateral and torsional vibration of half-through truss footbridges, March 2021
• AD 428: Draft guidance: lateral and torsional vibration of half-through truss footbridges, March 2019
• AD 427: Typographical error in P419, February 2019
• AD 426: Bolt head protrusion through nuts and threads in grip lengths, January 2019
• AD 425: Full depth stiffeners and lateral torsional buckling, January 2019
• AD 424: Shear stud length, November 2018
• AD 423: Reduction in bending resistance due to high shear, October 2018
• AD 422: Punching shear check for fin plates in P358, September 2018
• AD 421: Design responsibility for welds in fabricated plate girders, September 2018
• AD 420: Minimum values of shear and bending moment in beams with web openings, July 2018
• AD 419: Composite beams with different positions of web openings, June 2018
• AD 418: Web-post buckling in composite beams with rectangular and elongated web openings, May 2018
• AD 417: Resistance of sections to combined shear and bending, April 2018
• AD 416: Artificially reducing the effective width of slab to satisfy shear connection requirements, March 2018
• AD 415: Vertical tying of columns and column splices, February 2018
• AD 414: Slip-resistant connections to BS EN 1993-1-8, January 2018
• AD 413: Shear resistances of M12 bolts, January 2018
• AD 412: Issues related to coatings and availability of structural fasteners, November 2017
• AD 411: Design of web to flange welds in plate girders, October 2017
• AD 410: Pouring concrete to a constant thickness or to a constant plane, September 2017
• AD 409: Recent Blue and Orange Book developments, July 2017
• AD 408: Effective length of cantilevers, June 2017
• AD 407: Section Classification, May 2017
• AD 406: Transient response factors in vibration analysis of staircases, April 2017
• AD 405: Vibration assessment of transient response factors, March 2017
• AD 404: Columns in simple construction, February 2017
• AD 403: Steel strengths for fabricated haunches, January 2017
• AD 402: Design of end plate joints made with preloaded bolts subject to coincident shear and tension, Nov/Dec 2016
• AD 401a: Appropriate anchorage of parallel decking (Revised), March 2017
• AD 401: Appropriate anchorage of parallel decking, October 2016
• AD 400: The degree of shear connection in composite beams and SCI P405, September 2016
• AD 399: Design of partial penetration butt welds in accordance with BS EN 1993-1-8, July/Aug 2016
• AD 398: Net area for staggered holes in accordance with Eurocode 3, June 2016
• AD 397: UK NA to BS EN 1991-1-3: General Actions – Snow loads, May 2016
• AD 396: Tying resistance of flexible end plates in one-sided connections, March 2016
• AD 395: Nominally pinned connections and axial forces, April 2016
• AD 394: New Rules on the Selection of Execution Class for Structural Steel, February 2016
• AD 393: Minimum requirements for column splices in accordance with Eurocodes, January 2016
• AD 392: Frame stability tool on www.steelconstruction.info, Nov/Dec 2015
• AD 391: Lateral Torsional Buckling of rectangular plates in accordance with BS EN 1993-1-1, October 2015
• AD 390: Lateral Torsional Buckling of channels in accordance with EN 1993-1-1, September 2015
• AD 389: Acceptable design codes for CE Marking of fabricated steelwork, July/Aug 2015
• AD 388: Partial factors for material properties for design in the UK, June 2015
• AD 387: Elastic critical moment and correction factor (g) for bi-symmetric I-sections, May 2015
• AD 386: Clarification of notch dimensions and shear resistances in SCI P358 (Green Book on Simple Joints), February 2015
• AD 385: Questions and Answers on SCI P391, January 2015
• AD 384: Welding in cold-formed zones, Nov/Dec 2014
• AD 383: Use of alkali-zinc silicate paint in slip-resistant bolted connections, September 2014
• AD 382: Bending resistance and moment-shear interaction limits for longitudinally stiffened beams designed to EN 1993-1-5, July/Aug 2014
• AD 381: Fatigue assessment of non-standard bridge details, May/June 2014
• AD 380: What height of shear stud should be used in Eurocode 4?, Mar/Apr 2014
• AD 379: Tying resistances of full depth end plates, Jan/Feb 2014
• AD 378: Web resistance to transverse loads according to BS EN 1993-1-5, Nov/Dec 2013
• AD 377: Placement of headed stud shear connectors in troughs of profiled steel sheets with a central stiffener, Sep/Oct 2013
• AD 376: Fire design of concrete-filled hollow steel columns to Eurocode 4, July/Aug 2013
• AD 375: BS 2853:2011 Steel overhead runway beams, May/June 2013
• AD 374: Design of gusset plate connections, May/June 2013
• AD 373: Connections using preloaded bolts, subject to combined shear and tension, Mar/Apr 2013
• AD 372: Vibration checks of floors, Jan/Feb 2013
• AD 371: Design of cold-formed steel trapezoidal sheeting, Nov/Dec 2012
• AD 370: Weld design for beam end plate connections in accordance with SCI P358, Sep/Oct 2012
• AD 369: Steel bearing piles: Pile driving formulae and driving resistance, July/Aug 2012
• AD 368: Shear resistance of I-sections in P363, June 2012
• AD 367: Construction loading for composite slabs – update to P364, May 2012
• AD 366: Bolts and Pins – Background information ASM 22.3.12, April 2012
• AD 365: Welding of shear studs to galvanized steel beams, February 2012
• AD 364: Welding stainless steel, January 2012
• AD 363: Geotechnical actions on structures – choice of partial factors, Nov/Dec 2011
• AD 362: Headed shear studs – Resistance and minimum degree of shear connection in composite beams with decking, October 2011
• AD 361: Mono pitched portal frames in fire boundary conditions, September 2011
• AD 360: Movement joints in steel-framed buildings, July/Aug 2011
• AD 359: Weathering steel bolts, June 2011
• AD 358: Design thickness of cold formed members and sheeting, May 2011
• AD 357: Flexural buckling of Tees to EC3, April 2011
• AD 356: Design of compression stiffeners to BS EN 1993, March 2011
• AD 355: Hydrogen embrittlement of bolts, March 2011
• AD 354: Resistance of bolted connections in tension, for design to BS EN 1993-1-8, February 2011
• AD 353: Execution class for bridge steelwork, January 2011
• AD 352: Fatigue assessment of crane supporting structures to Eurocode 3, January 2011
• AD 351: Tension resistance of angles in SCI P363, Nov/Dec 2010
• AD 350: Heating pipes in composite floors – effects on slab beam design, Nov/Dec 2010
• AD 349: Shear resistance of Parallel Flange Channels in the Eurocode Blue Book, October 2010
• AD 348: Bolt resistance tables in the Eurocode Blue Book, September 2010
• AD 347: Saw cutting of composite slabs to control cracking, July/Aug 2010
• AD 346: Design actions during concreting for beams and decking in composite floors, June 2010
• AD 345: Load factors in BS 5950-1:2000 for crane loading, May 2010
• AD 344: Levelling techniques for composite floors, April 2010
• AD 343: Position of reinforcing mesh relative to stud shear connectors in composite slabs, March 2010
• AD 342: Stainless steel fasteners, February 2010
• AD 341: Corrigenda for P362, January 2010
• AD 340: Elastic Moduli of Angle Sections, January 2010

For earlier AD Notes, please visit NSC magazine and use the search facility. Alternatively, if you are an SCI member, they are also available on Steelbiz.