view mh28.3-ansi standard for work platforms

MH28.3 – 2009

Specification for the Design, Manufacture, and Installation of Industrial Steel Work Platforms

Abstract: An industrial steel work platform is a prefabricated elevated platform located in an industrial environment, pre-designed using a steel framing system. Flooring may include other structural or non-structural elements such as, but not limited to, concrete, steel, and/or engineered wood-products. This Specification is intended to be applied to the design, manufacturing, installation, and maintenance of such structures.

A Product Section of Material Handling Industry of America

A Division of Material Handling Industry 8720 Red Oak Blvd., Suite 201

Charlotte, NC 28217-3992 [email protected]

© 2009 by Material Handling Industry All rights reserved.

mailto:[email protected]

American National Standard Approval of an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations should be addressed to the sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Published by Storage Equipment Manufacturers Association A Product Section of Material Handling Industry of America (MHIA), MHIA is a division of Material Handling Industry 8720 Red Oak Blvd., Suite 201, Charlotte, NC, 28217-3992 Telephone: (704) 676-1190 www.mhia.org/sma [email protected] © 2009 by Material Handling Industry All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher, SMA. Printed in the United States of America.

MH28.3: 2009

American National Standard


Storage Equipment Manufacturers Association (SMA) A Product Section of Material Handling Industry of America (MHIA), MHIA is a Division of Material Handling Industry Approved October 27, 2009 American National Standards Institute, Inc.

American National Standard MH28.3: 2009 Specification for the Design, Manufacture and Installation of Industrial Steel Work Platforms

Disclaimer

This Specification was developed under Material Handling Industry procedures and approved by ANSI on 27 October 2009. It represents suggested design practices, manufacturing, and installation criteria for industrial steel work platforms. It was developed with the sole intent of offering information to parties engaged in the manufacturing, marketing, purchasing, or use of industrial steel work platforms. This Specification is advisory only and acceptance is voluntary and the standard should be regarded as a guide that the user may or may not choose to adopt, modify, or reject. The information does not constitute a comprehensive safety program and should not be relied upon as such. Material Handling Industry (MHI), Storage Equipment Manufacturers Association (SMA), and their members assume no responsibility and disclaim all liability of any kind, however arising, as a result of acceptance or use or alleged use of this Specification. The user specifically understands and agrees that the MHI and SMA and their officers, agents, and employees shall not be liable under any legal theory of any kind for any action or failure to act with respect to the design, erection, installation, manufacturing, preparation for sale, sale, characteristics, features, or delivery of anything covered by this standard. Any use of this information must be determined by the user to be in accordance with applicable federal, state, and local laws and regulations. MHI and SMA make no warranties of any kind, expressed, implied, or statutory, in connection with the information in this standard. MHI and SMA specifically disclaim all implied warranties of merchantability or of fitness for particular purpose. By referring to or otherwise employing this Specification, the user agrees to defend, protect, indemnify, and hold MHI and SMA and their officers, agents, and employees harmless from and against all claims, losses, expenses, damages, and liabilities, direct, incidental, or consequential, arising from acceptance or use or alleged use of this Specification, including loss of profits and reasonable attorney’s fees which may arise out of the acceptance or use or alleged use of this standard. The intent of this provision and of the user is to absolve and protect MHI and SMA and their officers, agents, and employees from any and all loss relating in any way to this Specification, including those resulting from the user’s own negligence.

ii


Foreword (This foreword is not part of American National Standard MH28.3-2009) The Storage Equipment Manufacturers Association, hereinafter referred to as SMA, is a product section of the Material Handling Industry of America (MHIA), a division of the Material Handling Industry (MHI), and is comprised of manufacturers engaged in the design, fabrication, testing, sale, and installation of storage equipment. The membership of SMA is made up of companies which produce the majority of the industrial steel work platforms as defined by the scope of this Standard. Material Handling Industry The Material Handling Industry (MHI) provides SMA with certain services and, in connection with this Standard, arranges for its production and distribution. The Material Handling Industry nor its officers, directors, and employees have any other participation in the development and preparation of the information contained in the Standard. All inquiries concerning the Standard should be directed in writing to the SMA Engineering Committee, 8720 Red Oak Boulevard, Suite 201, Charlotte, NC 28217. The use of this Standard is permissive, not mandatory. Voluntary use is within the control and discretion of the user and is not intended to, and does not in any way limit the ingenuity, responsibility, or prerogative of individual manufacturers to design or produce industrial steel work platforms which do not comply with this Standard. SMA has no legal authority to require or enforce compliance with this Standard. This advisory Standard provides technical guidelines to the user for his specific application. Following the Standard does not assure compliance with applicable federal, state, or local regulations and codes. This Standard is not binding on any person and does not have the effect of law. The SMA and the Material Handling Industry do not take any position regarding any patent rights or copyrights which could be asserted with regard to this Standard and does not undertake to ensure anyone using this Standard against liability, nor assume any such liability. Users of this Standard are expressly advised that determination of the validity of any such copyrights, patent rights, and risk of infringement of such rights is entirely their own responsibility. In the interest of safety, all users of work platforms are advised to regularly inspect and properly maintain the structural integrity of their structure by assuring proper operational, housekeeping, and maintenance procedures. Users of the Standard must rely on competent advice to specify, test, and/or design the industrial steel work platform for their particular application. This Standard is offered as a guideline. If a user refers to, or otherwise employs, all or any part of this Standard, the user agrees to follow the terms of indemnity, warranty disclaimer, and disclaimer of liability. The members of SMA at the date of approval were: Cooper B-Line Cornerstone Specialty Wood Products, LLC Excel Storage Products, LP MBG-Meiser Bartley Gratings LLC Penco Products, Inc. Schaefer Systems International, Inc.

SpaceRak, Div. of Heartland Steel Products, Inc. Steel King Industries, Inc. Tri-Boro Shelving & Partition Corp. Unarco Material Handing, Inc. Western Pacific Storage Solutions Wildek, Inc.

iii


Table of Contents

1.0 Overview…………………………………………………………………………......1

2.0 Definitions……………………………………………………………………………3

3.0 General Provisions………………………………………………………………….6

4.0 Referenced Standards……………………………………………………………...8

5.0 Means of Egress…………………………………………………………………...10

6.0 Guards………………………………………………………………………………13

7.0 Materials…………………………………………………………………………….15

8.0 Loading……………………………………………………………………………..16

9.0 Structural Design…………………………………………………………………..18

10.0 Fabrication, Installation Quality, and Special Inspections……………………..20

11.0 Protection…………………………………………………………………………...21

iv



1.0 Overview 1.1 Scope

1.1.1 This Specification applies to industrial steel work platforms. An industrial steel

work platform is a prefabricated elevated platform located in an industrial environment, pre-designed using a steel framing system. Flooring may include other structural or non-structural elements such as, but not limited to, concrete, steel, and/or engineered wood-products. The people working on such a platform shall be trained employees, accustomed to a manufacturing or warehouse environment and dressed accordingly.

1.1.2 This Specification is intended to be applied to the design, manufacturing, installation, and maintenance of such structures. 1.1.3 Industrial steel work platforms are hereinafter be referred to as “work

platforms”. 1.2 Integrity of work platforms

The owner shall maintain the integrity of the installed work platform by assuring proper operational housekeeping and maintenance procedures including, but not limited to, the following:

1.2.1 Prohibit overloading at any one area or the overall platform. 1.2.2 Keep the guardrail and handrail in place under normal conditions. 1.2.3 Keep access and egress stairways free of debris. 1.2.4 Properly enforce application restrictions as stated in the scope of this Specification. 1.2.5 When damaged, immediately unload the appropriate area of the structure,

then repair or replace the damaged component(s).

1


1.3 Plaques 1.3.1 The work platform shall have plaques of not less than 50 square inches (325

square centimeters) displayed in the following locations: 1.3.1.1 Clearly visible on at least one riser of each stairway or other means of access. 1.3.1.2 On each access gate. 1.3.2 The plaques shall show in clear, legible print the maximum permissible

uniformly distributed live load for the work platform. Special loads shall also to be indicated on the plaque(s).

2


2.0 Definitions

Unless otherwise expressly stated, the following words and terms shall, for the purposes of this Specification have the meanings shown in this section.

Interchangeability. Words used in the present tense include the future; words stated in the masculine gender include the feminine and neuter; the singular number includes the plural and the plural, the singular.

Terms not defined. Where terms are not defined through the methods authorized by this section, such terms shall have ordinarily accepted meanings such as the context implies.

2.1 Access gates A gate that provides access through the guardrail to allow workers to pass materials, tools, or equipment. 2.2 Alternating tread device

A device that has a series of steps between 50° and 70° (0.87 and 1.22 radians) from horizontal, usually attached to a center support rail in an alternating manner so that the user does not have both feet on the same level at the same time.

2.3 Building official The officer or other designated authority charged with the enforcement and administration of the local building code, or a duly authorized representative. 2.4 Building permit An official document or certificate issued by the building official having jurisdiction which authorizes performance of a specified activity. 2.5 Curved stairway

A curved stairway that has the smallest radius that is not less than twice the required width of the stairway.

2.6 Egress

A continuous unobstructed path of vertical and horizontal travel from any occupied portion of a building or structure to a public way.

3


2.7 Fire-area

The aggregate floor area enclosed and bounded by fire walls, fire barriers, exterior walls, or fire resistance-rated horizontal assemblies of a building.

2.8 Fire-protection system

Approved services, equipment, and systems or combinations of systems used to detect a fire, activate an alarm, extinguish or control a fire, control or manage smoke and products of a fire, or any combination thereof.

2.9 Guardrail (or guarding)

A building component or a system of building components located at or near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the elevated surface to a lower level. 2.10 Handrail

A horizontal or sloping rail intended for grasping by the hand for guidance or support. 2.11 Live load

Those loads produced by the use and occupancy of a work platform and do not include construction or environmental loads such as wind, snow, rain, earthquake, flood, or weight of the structure. 2.12 Local building code

A document written by or approved by local government officials that addresses the minimum regulations for construction in that locality.

2.13 Means of egress

A continuous and unobstructed path of vertical and horizontal egress travel from any occupied portion of a building or structure to a public way. A means of egress consists of three separate and distinct parts: the exit access, the exit, and the exit discharge.

2.14 Plaque

A plate, placard, or decal that is mechanically or otherwise securely

attached to the work platform that displays the maximum uniformly distributed live load for the structure.

4


2.15 Ramp

A walking surface that has a running slope steeper than one unit vertical in 20 units horizontal (5% slope). 2.16 Registered design professional

An individual who is registered or licensed to practice their respective design profession as defined by the statutory requirements of the professional registration laws of the state or jurisdiction. Typically, the design calculations and construction drawings are certified by a registered design professional licensed in the State where the work platform is located.

2.17 Spiral stairway

A stairway having a closed circular form in its plan view with uniform section-shaped treads attached to and radiating from a minimum diameter supporting column.

2.18 Story (one level of a building)

That portion of a building included between the upper surface of a floor and the upper surface of the next floor or roof. It is measured as the vertical distance from top-to-top of two successive tiers of beams or finished floor surfaces and, for the topmost story, from the top of the floor finish to the top of the ceiling joists.

2.19 Type of construction

In the construction industry, the term “type of construction” is commonly used with two meanings; therefore, two definitions are provided:

2.19.1 As used in Section 3.1, a classification of construction materials, when

combined, provide a fire-resistance rating for a building. The selection of the type of construction for the structure is determined by the registered design professional based on the usage and size of the structure.

2.19.2 As used in Section 9.2, a classification of structural design assumptions used for analysis of framing systems in a steel structure. The acceptable classifications are defined in the AISC and AISI design documents.

5


3.0 General Provisions General provisions of a work platform shall be as required by the local building code, except as specified or clarified herein. 3.1 Type of construction

This Specification is intended for work platforms made from steel. All

structural components in the framing system shall be made from steel as specified in Section 7.0. The non-structural walking surface of the deck may be composed of a variety of material including combustible materials such as, but not limited to, engineered wood flooring. 3.2 The clear height below a work platform shall not be less than 7’-0” (2.13 m).

Exception: If a work platform is built over equipment, vessels, etc., and/or there will be no one working under the platform except for repairs or cleaning, the work platform may have a clear height such that it clears the equipment and has sufficient clearance to accommodate repair or maintenance activities.

3.3 The clear height above a work platform shall not be less than 7’-0” (2.13 m).

Exception: If a work platform is used to support equipment, vessels, etc., and/or there will be no one working on the platform except for repairs or cleaning, the clear height above the work platform may be such that it has sufficient clearance to accommodate repair or maintenance activities.

3.4 The aggregate floor area of all work platforms within a fire-area shall not

exceed ⅔ of the total fire-area for the room in which they are located. 3.5 The area of a work platform shall not be included in determining the fire area. 3.6 Work platforms shall not serve as a part of the means of egress from a

building. 3.7 Work platforms shall not contribute to either the building area or the number

of stories as regulated by the local building code. 3.8 Each worker on a work platform shall have access to at least two independent

means of egress when the common path of egress travel exceeds 75 feet (23 m). When a stairway provides the means-of-egress from a work platform, the maximum travel distance shall include the distance traveled on the stairway measured in the plane of the tread nosing along the tread centerline. Exception: The length of the required path and egress from a work platform shall not be more than 100 feet (30.48 m) provided that the building is

6


equipped throughout with an automatic sprinkler system installed in accordance with the requirements of the local building code.

3.9 Guarding shall be provided as required in Section 6.0. 3.10 Means of egress shall be provided as required in Section 5.0. 3.11 Access gates shall be as required in Section 6.4. 3.12 Fire-protection system

Where located in a building that is required to be protected by an automatic sprinkler system, work platforms shall be fully protected by sprinklers above and below the platform as required by the local building code.

3.13 Column base plates and anchors

The bottom of all columns shall be furnished with column base plates. All columns shall be anchored to the supporting floor or foundation with anchor bolts suitable to resist all horizontal and vertical loads on the work platform. 3.14 Work platforms may be connected to the building structure

If a work platform is connected to the building structure, the magnitude and location of the maximum possible loads that are imposed on the building by the work platform or on the work platform by the building shall be considered in the design of the work platform and the building structure. Such loads that are imposed by the building onto the work platform shall be provided by the building owner or his representative to the work platform designer. Such loads that are imposed by the work platform onto the building structure shall be provided by the work platform designer to the owner for evaluation by a registered design professional.

3.15 Load application and platform configuration drawings

Load application and configuration drawings shall be furnished with all work platforms. A copy shall be retained by the owner.

7


4.0 Referenced Standards

In each referenced standard listed below, the intent is to refer to the latest edition.

4.1 AISC—American Institute of Steel Construction

AISC 325-05 Steel Construction Manual, Thirteenth Edition. www.aisc.org

4.2 AISI—American Iron and Steel Institute

AISI-NASPEC—North American Specification for Design of Cold Formed Steel Structural Members. www.steel.org

4.3 ASCE—American Society of Civil Engineers

ASCE-7—Minimum Design Loads for Buildings and Other Structures. www.asce.org

4.4 ASTM International

ASTM standards for structural steel as found in 4.2 and 4.3 www.astm.org

4.5 AWS—American Welding Society www.aws.org

4.5.1 D1.1-00 Structural Welding Code—Steel. 4.5.2 D1.3-98 Structural Welding Code—Sheet Steel.

4.6 ICC / IBC / IFC—International Code Council / International Building Code

/ International Fire Code www.iccsafe.org

4.7 NAAMM—National Association of Architectural Metals Manufacturer’s

Metal Bar Grating Manual www.naamm.org

4.8 OSHA— US Department of Labor Occupational Safety and Health

Administration Standards www.osha.gov

4.9 SJI—Steel Joist Institute www.steeljoist.org

8


4.9.1 SJI Standard Specification for Joist Girders. 4.9.2 K-Series Specification Standard Specification for Open Web Steel Joists, K

Series. 4.9.3 SJI Standard Specification for Long Span Steel Joists, LH Series and Deep

Longspan Steel Joists, DLH Series. 4.10 SDI—Steel Deck Institute www.sdi.org 4.10.1 #30 Design Manual for Composite Decks, Form Decks, and Roof Decks. 4.11.2 #RDCHI Roof Deck Construction Handbook.

9


5.0 Means of Egress 5.1 Circular stairs, as specified in the local building code, shall be permitted. 5.2 Spiral stairways, alternating tread stairways, and industrial ladders, are

permitted as a means of egress from a work platform as long as the decked surface is not in excess of 250 square feet (23 square meters) and there are no more than five (5) occupants on the decked surface at one time. These means of egress shall be designed in accordance with the local building code. In the absence of a local building code, they shall conform to the appropriate provisions of OSHA.

5.3 Ramps, as specified in the local building code, shall be permitted.

5.4 Stairways 5.4.1 Stairway width.

The width of stairways shall not be less than 36 inches (91.4 cm).

Exception. Stairways serving as access to a work platform used only to support equipment, vessels, etc., and where there will be no one working on them except for repairs or cleaning, may be 30 inches (76.2 cm).

5.4.2 Headroom. Stairways shall have a minimum headroom clearance of 80 inches (203 cm)

measured vertically from a line connecting the edge of the nosings. Such headroom shall be continuous above the stairway to the point where the line intersects the landing below, at a point one tread depth beyond the bottom riser. The minimum clearance shall be maintained the full width of the stairway and landing.

5.4.3 Stair treads and risers.

Stair riser heights shall be 8 inches (20.3 cm) maximum and 4 inches (10.2 cm) minimum. Stair tread depths shall be 8¾ inches (22.2 cm) minimum. The riser height shall be measured vertically between the leading edges of adjacent treads.

5.4.4 Dimensional uniformity.

Stair treads and risers shall be of uniform size and shape. The greatest riser height within any flight of stairs shall not exceed the smallest by more than ⅛ inch (3 mm). The tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at right angle

10


to the tread’s leading edge. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than ⅜ inch (10 mm).

5.4.5 Profile.

The radius of curvature at the leading edge of the tread shall not be greater than ½ inch (13 mm). Beveling of nosings shall not exceed ½ inch (13 mm). The nosing shall be a minimum of 1½ inches (3.8 cm) deep with a return of not less than 1 inch (2.54 cm). The leading edge (nosing) of treads shall project not more than 1¼ inches (3.2 cm) beyond the tread below and all projections of the leading edges shall be of uniform size, including the leading edge of the floor at the top of a flight.

5.4.6 Risers may be open or closed. 5.4.7 Stairway walking surface.

The walking surface of treads and landings of a stairway shall not be sloped steeper than one unit vertical in 48 units horizontal (2% slope) in any direction. Stairway treads and landings may have a solid surface or be open provided the openings do not allow a 1½ inch (3.8 cm) diameter sphere to pass through.

5.4.8 Stairway landings.

There shall be a floor or landing at the top and bottom of each stairway. The width of landings shall not be less than the width of stairways they serve. Every landing shall have a minimum dimension measured in the direction of travel equal to the width of the stairway. Such dimension need not exceed 48 inches (1.22 m) where the stairway has a straight run.

5.4.9 Vertical rise.

A flight of stairs shall not have a vertical rise greater than 12 feet (3.66 m) between floor levels or landings.

5.5 All stairways shall have guarding as specified in Section 6.0.

5.6 Handrails. Stairways shall have handrails on each side. Handrails shall be adequate in strength and attachment in accordance with Section 8.3. 5.6.1 Height.

Handrail height measured above stair tread nosing shall be uniform, not less than 34 inches (86.4 cm) and not more than 38 inches (96.5 cm).

11


5.6.2 Intermediate handrails.

Intermediate handrails are required so that all portions of the stairway width required for egress capacity are within 30 inches (76.2 cm) of a handrail.

5.6.3 Handrail graspability.

Handrails with a circular cross section shall have an outside diameter of at least 1¼ inches (3.2 cm) and not greater than 2 inches (5.1 cm) or shall provide equivalent graspability. If the handrail is not circular, it shall have a perimeter dimension of at least 4 inches (10.2 cm) and not greater than 6¼ inches (15.9 cm) with a maximum cross-section dimension of 2¼ inches (5.7 cm). Edges shall have a minimum radius of 0.01 inch (.25 mm).

5.6.4 Clearance.

Clear space between a handrail and a wall or other surface shall be a minimum of 1½ inches (3.8 cm). The handrail and any wall or other surface adjacent to the handrail shall be free of sharp edges or abrasive elements.

5.6.5 Stairway projections.

Projections into the required width at each handrail shall not exceed 4½ inches (11.4 cm) at or below the handrail height. Projections into the required width shall not be limited above the minimum headroom height required in Section 5.4.2.

5.6.6 Handrails need only extend from the end of the top riser to the end of the bottom riser.

5.6.7 Handrails are permitted to be interrupted at landings and levels. Handrails

shall gradually become higher at landings and levels such that there is a smooth transition into the guarding at that level.

5.6.8 Handicap accessibility.

Stairways need not be designed for handicap accessibility.

12


6.0 Guards 6.1 Where required

Guards shall be located along the open side of all work platforms that are more than 30 inches (76.2 cm) above the floor or grade below. Guards shall meet the strength and attachment requirements of Section 8.3. Guards shall also be located along sides of stairways and landings that are located more than 30 inches (76.2 cm) above the floor or grade below.

6.2 Height

Guards shall form a protective barrier not less than 42 inches (1.1 m) high measured vertically above the adjacent walking surface.

Exception: Handrails along the open side of a stairway provided in accordance with Section 5.6 may serve as guarding for the stairway provided they conform to the height specified in Section 5.6.1.

6.3 Opening limitations 6.3.1 Open guards shall have balusters, intermediate horizontal rails, or ornamental

patterns such that a 21 inch (53.3 cm) diameter sphere cannot pass through any opening.

6.3.2 Guards that are interrupted due to interference for any reason shall be

terminated no more than 4 inches (10.2 cm) from the object creating the interference. Exception: guards that are interrupted by a stairway or other means of egress shall be terminated no less than 1½ inches (3.8 cm) nor more than 4 inches (10.2 cm) from the handrail for the means of egress, unless that stairway handrail extends horizontally a minimum of 12 inches (30.5 cm) into the work platform area.

6.4 Access openings in guards 6.4.1 All gates that provide access through guards must meet the strength and

attachment requirements of Section 8.4. 6.4.2 All gates that provide access through guards must be at least 42 inches (1.1

m) high and have a kick plate on the open side in accordance with Section 6.5.

6.4.3 Any gate that provides an access opening through the guards for the purpose

of loading and unloading material onto a work platform shall be designed

13


such that the elevated surface is protected by guards at all times. Gates that swing open, slide open, or lift out leaving an unprotected opening in the guarding are not acceptable.

6.4.4 Gates that provide access openings through guards for purposes other than Section 6.4.3 above may swing, slide, or lift-out leaving an unprotected opening are permissible provided the worker on the elevated surface is protected by other means than the guarding. 6.5 Kick plate

All areas requiring guardrails in accordance with the above paragraphs shall be provided with a solid kick plate that extends is a minimum of 4 inches (10.2 cm) above the walking surface with no more than a ¼ inch (3 mm) clearance above the floor. There shall be no horizontal opening in the kick plate in excess of 1 inch (2.5 cm).

14


7.0 Materials 7.1 The steel furnished for the structural load-carrying members of a work

platform shall be properly identified as conforming to the grade ordered in accordance with the specified ASTM standard (or other specification) and the provisions of this section. Steel that is not readily identifiable as to grade from the markings and test records shall be tested to verify conformity to such standards.

7.2 Steel of structural quality, as defined by the ASTM specifications listed in

AISC 325-05, shall be used for steel work platforms.

7.3 Sheet metal used for structural members shall be as defined by the ASTM specifications listed in AISI-NASPEC.

7.4 The walking surface may be composed of a variety of materials, both

combustible and non-combustible, such as, but not limited to, combustible engineered wood products, concrete, solid plate, bar grating, plank grating, or press-grating, designed for the application.

15


8.0 Loading 8.1 Load combinations

The nominal loads and load combinations shall be as stipulated by the applicable code under which the work platform is designed or as dictated by the conditions involved, except as modified or clarified below. In the absence of a code, the loads and load combinations, including impact and crane loads, shall be those stipulated in ASCE 7. For design purposes, the loads stipulated by the applicable code or ASCE 7 shall be taken as nominal loads.

8.2 Additional or heavier loads

Intended usage of the work platform may dictate heavier loads that are not addressed by the local code or ASCE7. Any heavier design load shall be determined by the registered design professional in consultation with the user of the work platform. Concentrated loads shall be considered in the design of a work platform. Examples of concentrated or point loads are: • Loading from storage rack or shelving supported by the work platform. • Loading from moving equipment on the work platform. • Loading from storage vessels supported by the work platform. • Loading from workstations, equipment, or conveying devices. • Locally heavy loads at gates or loading areas.

8.3 Handrails and guards 8.3.1 Handrail assemblies and guards shall be designed to resist a uniformly

distributed load of 20 pounds per linear foot (29.8 kg/m) and a concentrated load of 200 pounds (90.7 kg), acting non-concurrently, applied in any direction at the top rail and to transfer this load through the supports to the structure.

8.3.2 Components.

Intermediate rails (all those except the handrail), balusters, and panel-fillers shall be designed to withstand a horizontally-applied load of 50 pounds (22.7 kg) on an area equal to 1 square foot (.093 square meters). Reactions due to this loading are not required to be superimposed with those of Section 8.3.1.

8.3.3 Stress increase.

Where handrails and guards are designed in accordance with the provisions for allowable stress design (working stress design) exclusively for the loads

16


specified in Section 8.3.1, the allowable stress for the members and their attachments are permitted to be increased by one-third.

8.4 Gates that provide access through guards shall be able to resist the same

loading as the guard.

Stairways shall be designed for a uniform load of 100 pounds per square foot (487.8 kg per square meter) and a local concentrated load of 300 pounds (136.1 kg), acting non-concurrently, over an area of 4 square inches (26 square centimeters) placed anywhere on the stairway.

8.5 Serviceability 8.5.1 The live load deflection of the structural floor beams shall not exceed L/180,

where L is the clear span of the beam. 8.5.2 Frequently, because of the type of activity on a work platform surface, it is

necessary to maintain live load deflections at more restrictive limits. These limits shall be dictated by the manufacturer of the supported equipment or by the end user of the work platform.

17


9.0 Structural Design 9.1 Design of the structural framing systems or the structural steel framing

members shall be as specified in AISC A325-05 and AISI-NASPEC.

9.2 Types of construction.

The type of framing construction shall be at the discretion of the design engineer and in accordance with the design specifications as specified in Section 9.1.

9.3 Structural steel design shall be in accordance with the local building code.

9.4 Design for earthquake loads shall be in accordance with the local building

code.

In the absence of specific instructions in the local building code, procedures as specified in the latest editions of the International Building Code and ASCE 7 shall be used.

9.5 Design for snow and wind loads. 9.5.1 If a work platform is located inside a building, wind loads and snow loads do

not apply. 9.5.2 Should a work platform be located outdoors, design for wind and snow shall

be in accordance with the local building code. In the absence of specific instructions in the local building code, procedures as specified in the latest editions of the International Building Code and ASCE 7 shall be used.

9.5.3 Work platforms located outdoors are assumed to be set atop a concrete

footer, a concrete slab-on-grade, or other suitable substructure capable of supporting the design loads.

9.6 Design of bar joists shall be in accordance with SJI specifications.

9.7 Design of bar grating shall be as specified in NAAMM, Metal Bar Grating Manual.

9.8 Design of anchors shall be in strict accordance with the manufacturer’s

approval from an agency recognized by local authorities or the local building code.

9.9 Design of roof decking used as a structural floor shall be in accordance with

SDI specifications.

18


9.10 The manufacturers of work platforms are not responsible for the design of concrete footers or the slab-on-grade.

9.11 For work platforms installed atop the slab-on-grade, the design of the column

base plates shall account for the strength of the floor.

19


10.0 Fabrication and Installation Quality, Special Inspections 10.1 The provisions of this section shall govern the quality, workmanship, and

material requirements. 10.2 All material used in construction shall be in accordance with Section 7.0.

10.3 The building permit application shall include a statement of special

inspections prepared by the registered design professional.

This statement shall include a complete list of materials and work requiring special inspections in accordance with the local building code.

10.4 Where the fabrication of structural load bearing members and assemblies is being performed on the premises of a fabricator’s shop, special inspection of the fabricated items shall be as required by the local building code.

10.4.1 Special inspections are not required where the work is done on the premises of a fabricator registered and approved to perform such work without special inspection. 10.4.2 Approval shall be based upon review of the fabricator’s written procedural and

quality control manuals and periodic auditing of fabrication practices by an approved special inspection agency.

10.5 All welding shall be performed by welders certified to AWS procedures and

processes.

10.6 On-site assembly shall be performed in accordance with the applicable provisions of AISC A325-05 or AISI-NASPEC as dictated by the registered design professional.

10.7 Bolted connections, decking, and anchors shall be installed in accordance

with the drawings as certified by the registered design professional.

10.8 Bar joists shall be installed in accordance with the applicable provisions of SJI.

10.9 On-site inspections shall be performed as dictated by the instructions of the registered design professional as required in Section 10.3.

20


11. Preparation and Protection Painting of structural steel shall comply with the requirements contained in

AISC A325-05,

Individual structural members and assembled panels of cold-formed steel construction, except where fabricated of approved corrosion-resistant steel or of steel having a corrosion resistant or other approved coating, shall be protected against corrosion with an approved coat of paint, enamel or other approved protection.

21

view mh28.3-ansi standard for work platforms

Documents