1、ANSI-ASC A14.4-2009Revision of A14.4-2002 American National StandardsAmerican National Standard Safety Requirements for Job-Made Wooden LaddersANSI-ASCnullA14.4-2009Revision of ANSI A14.4 2002American National Standard Safety Requirements for Job-Made Wooden LaddersSecretariatAmerican Ladder Institu
2、te Approved March 10, 2009American National Standards Institute, Inc.For information on possible errata sheets and other ANSI-ASC A14 Standards please refer to the ALI website located at:www.americanladderinstitute.orgAn American National Standard implies a consensus of those substantially concerned
3、 with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an American National Standard does not in any respect preclude anyone, whether they have approved the standard or not, from manufacturi
4、ng, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. American National Standards are subject to periodic review and users are cautioned to obtain the latest editions and errata sheets.The American National Standards Institute does not develop standar
5、ds and will in no circumstances give an interpretation of any American National Standard. Moreover, no persons shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute.CAUTION NOTICE: This American National
6、 Standard may be revised or withdrawn at anytime. The procedures of the American National Standards Institute require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of publication. Purchasers of American National Standards may receive curre
7、nt information on all standards by calling or writing the American National Standards Institute.Published byAmerican Ladder Institute 401 N. Michigan Avenue, Chicago, IL 60611Copyright by ANSI Accredited Standards Committee (ASC) A14 All rights reserved.No part of this publication may be reproduced
8、in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher.Printed in the United States of AmericaAmerican National StandardiiForewordiii(This Foreword is not a part of the American National Standard A14.4 2009.)This standard is a revision of A
9、merican National Safety Standard for Job-Made Wooden Ladders, ANSI A14.4-2002. It is one of a series of seven standards prepared under the supervision of American National Standards Committee ASC A14. All seven standards have been developed by subcommittees reporting to American National Standards C
10、ommittee ASC A14. The subcommittees are: A14.l, Portable Wood Ladders; A14.2, Metal Ladders; A14.3, Fixed Ladders; A14.4, Job-Made Wooden Ladders, A14.5, Portable Reinforced Plastic Ladders, A14.7, Mobile Ladder Stands and Mobile Ladder Stand Platforms and A14.9, Ceiling Mounted Disappearing Climbin
11、g Systems.Subcommittee A14.4 was created for the purpose of developing a safety standard covering job-made wooden ladders used on construction sites. It had been the recommendation of the American National Standards Committee on Safety in Construction and Demolition Operations, AlO, and the ANSI Saf
12、ety Technical Advisory Board that a safety standard for job-made wooden ladders be developed by American National Standards Committee on Construction, Care, and Use of Ladders, ASC A14, and Subcommittee A14.4 on Job-Made Wooden Ladders was established by vote of the ASC A14 Standards Committee at a
13、meeting on May 23, 1972.Following are the most significant aspects of this current revision: Table 1 has been simplified by listing those acceptable lumber grades that are most commonly available, by allowing all lumber grades that meet a minimum threshold, and by allowing the use of lower grade lum
14、ber when corresponding ladder components are increased in size. Engineering calculations were made affirming the grades and sizes specified in Tables 1, 2 and 3. Language on safe use of ladders was simplified for clarity and consistency with other standards. Figures were revised with dimensioning de
15、tails adjusted to coincide with other standards and safer recommended practice.Suggestions for improvement of this standard will be welcome. They should be sent to the ASC A14 Committee c/o the Amercian Ladder Institute at 401 N. Michigan Avenue, Chicago, IL 60611. All comments must be sent on the O
16、fficial Comment Form that can be found on the last page of this document. Each comment must include a rationale.This standard was processed and approved for submittal to ANSI by American National Standards Committee on Construction, Care, and Use of Ladders, ASC A14. Committee approval of the standa
17、rd does not necessarily imply that all the committee members voted for its approval. At the time it approved this standard, the ASC A14 Committee had the following members:Erick Knox, ChairmanDon Gibson, Vice ChairJanet Rapp, SecretariatOrganization Represented Name of RepresentativeAmerican Insuran
18、ce Association . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .George EarhartThomas Murray (Alt)American Ladder Institute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19、 . . . Marc McConnellAmerican Society of Safety Engineers .Michael LorenzoAssociated General Contractors of America . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Charles BirdMichele Myers (Alt)Canadian Standards Association Walter DickCosco Home
20、and Office Products Eric KruseTerry Emerson (Alt)Disappearing Attic Stairway Association Dennis WilliamsBrad HudspethIllinois Association of Building Maintenance Contractors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carl Pedersen James Weil (Alt)International Brothe
21、rhood of Electrical Workers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . James TomaseskiInternational Brotherhood of Painters and Allied Trades Brian GustineInternational Union of Bricklayers that is, the horizontal distance from the base of the ladder to the
22、 supporting surface shall not be greater than times the ladder working length. Ladders with spliced rails shall not be used at a pitch flatter than 1 in 8.6.3 Base Position.The base of rails shall be positioned so that the pitch complies with the rail dimensions listed in Tables 2 and 3. To determin
23、e the maximum horizontal distance in feet from the base of the ladder to the bearing surface, multiply the working length by the pitch.6.4 Securing Base.The method of securing the base against accidental displacement shall be determined based on the type of bearing surface and the pitch. Suggested m
24、ethods are shown in Fig. 3 and 7. As the pitch flattens, stronger security attachments should be used.6.5 Securing Top.The ladder shall be positively fastened to a secure object as near as possible to the top point of bearing but within the top one quarter of the ladder working length.American Natio
25、nal Standard A14.4-200946.6 Security Attachments.Security attachments shall be affixed directly to each side rail at the same elevation but not to the cleats and in such a way as to not add an encumbrance to the user. Security attachments should not encroach into the climbing area. When flexible mat
26、erials such as rope or wire are used, they shall be tensioned such that the ladder is held firmly in position.6.7 Landings.Safe landings shall be provided at the top and bottom of all ladders. Where climbers access or egress from an uneven walking surface, a secured, temporary landing of plywood or
27、similar material, the width of the ladder and extending three feet from the ladder shall be provided. A handhold gap the depth of the rail shall be provided between the top cleat and the bearing point. The step-across distance at this point shall not exceed 12 in. Cleats shall be eliminated above th
28、e landing level, and side rails shall extend 36 to 45 in. above the landing for mounting and dismounting. Where multiple ladders are required, solidly-decked platforms shall be provided. Guardrails, intermediate rails, and toeboards shall be erected on the outside edges and exposed sides of the plat
29、form (see Fig. 8).7. Clearances7.1 General.Safe clearances as described below shall be maintained. Other clearances should be considered to help prevent users from bumping into, or snagging onto projecting objects while ascending or descending the ladder.7.2 Climbing Side.Ladders shall have a minimu
30、m clear perpendicular distance of 30 in. from the cleats to the nearest projecting object on the climbing side (see Fig. 9). When unavoidable obstructions are encountered, the minimum clearance may be reduced to 24 in. if deflector plates are provided (see Fig. 10).7.3 Side Clearance.The minimum dis
31、tance to the nearest fixed object shall be 15 in. on each side of the centerline of single-cleat ladders (see Fig. 8) or 6 in. from the outside rails of double-cleat ladders.7.4 Horizontal Clearance in Back of Ladder.The perpendicular distance from the face of the cleat on the climbing side to the n
32、earest fixed object on the back-side of the ladder shall be not less than 8 in. (See Fig. 9). When unavoidable horizontal obstructions, such as beams or pipes, are encountered, the vertical toe clearances specified in 7.5 shall apply.7.5 Vertical Clearance in Back of Ladder.The minimum vertical toe
33、clearance from intermediate horizontal obstructions shall be 1 in. below and 4 in. above the top edge of the cleat (see Fig. 11).7.6 Multiple Ladders.When two or more separate ladders are used with a landing platform, the side-step distance shall be a minimum of 15 in. from the centerline of the upp
34、er ladder (see Fig. 8) to the near side of the lower ladder.8. Inspection and Maintenance8.1 General.All job-made wooden ladders, landings, and security attachments shall be inspected at least once per week, and any defects that have developed shall be corrected immediately, or the ladder shall be t
35、aken out of service.8.2 Record Keeping.Inspection records shall be maintained indicating the date of inspection, the identification or location of the ladder and any remedial action required.8.3 Testing.Ladders shall not be subjected to load or impact tests. Such tests may weaken lumber components o
36、r fasteners, causing hidden damage that could result in sudden failure during use.8.4 Routine Maintenance.Safety considerations shall be observed each day while the job-made wooden ladder is in service.8.4.1 Cleats. Cleats shall be maintained free of deposits of oil, grease, ice and mud to a practic
37、al degree.8.4.2 Damaged Components. Ladders with loose, excessively worn, broken or missing cleats, broken or split side rails, or other defective parts shall be reported immediately and withdrawn from service until replaced or repaired.8.4.3 Splices. Bolted splice connections shall be checked to en
38、sure that nuts are tight.8.5 Housekeeping.The areas at the tops and the bottoms of ladders shall be maintained level and free of material or debris, to help ensure safe mounting and dismounting of the ladder.American National Standard A14.4-200958.6 Protective Coatings.Ladders shall not be painted w
39、ith an opaque coating that obscures the structural integrity of the ladder. If protective coatings are considered desirable, only transparent coatings or wood preservatives shall be used.9. Safe Use of Ladders9.1 GeneralSound safety practices in the use of job-made wooden ladders are given in 9.2 th
40、rough 9.5.9.2 Mounting and DismountingTo the extent practical, before mounting the ladder, personnel should ensure that their shoes are free from grease, oil, or mud. Users should step through, not around, the rail extensions at the top of the ladder.9.3 Ascending and Descending.When ascending or de
41、scending the ladder, the user shall face the ladder and maintain a firm grip on the ladder. The user shall not run up or down, or slide down the ladder at any time.9.4 Transporting Material.To the extent practical, a hand line should be used for raising and lowering tools and materials. Objects of s
42、ufficient weight and size that could cause loss of balance shall not be carried on a ladder.9.5 Intended Use.The ladder should be used only for the purpose intended (by the design). Job-made wooden ladders shall not be used for guys or braces, or hoist supports or structural functions other than tho
43、se of a ladder.Table 1Examples of Acceptable Stress-Grade Lumber for Job-Made Wooden Ladders1Species for Visual Grades and Machine Grading AcronymsMinimum Grade2Any commercial species groupGrades which have an allowable stress in bending after adjustment for size, Fb, that is not less than 1200 psi
44、(pound-force per square inch) and the corresponding reference strength (for Load and Resistance Factor Design) is not less than 3050 psi.Douglas fir-larch No. 2Douglas fir-larch (north) No. 1/No. 2Dougls fir-larch (south) No. 2Hem-fir No. 2Hem-fir (North) No. 1/No. 2Spruce-Pine-Fir No.1/No. 2Spruce-
45、Pine-Fir (south) No. 1Southern Pine No. 2 (nondense)MSR 1200f-1.2EMEL M-7NOTES:(1) All lumber shall be identified with a grademark or certificate of inspection issued by a lumber inspection bureau or agency accredited by the Board of Review of the American Lumber Standard Committee.(2) Grades with a
46、 minimum allowable stress in bending after adjustment for size, Fb of 800 psi (pound-force per square inch) and a corresponding reference strength (for Load and Resistance Factor Design) of 2040 psi shall be acceptable if the sizes in Tables 2 and 3 are increased one standard size. That is a 2 x 6 r
47、eplaces the requirement of a 2 x 4 and a 2 x 8 replaces the requirement of a 2 x 6. The resulting lower grades are acceptable if other grade reducing characteristics such as wane and warp do not interfere with the function and safety of the ladder. This note does not apply to spliced rails.American
48、National Standard A14.4-20096Table 2Minimum Rail Size for Single-Cleat Ladders3(Nominal-Dimension Lumber)Working Length (feet)Pitch (H/L) (See Note 1)Vertical 1/10 1/8 1/6(3)1/4(3)12 or less 2 x 4 2 x 4 2 x 4 2 x 4 2 x 414 2 x 4 2 x 4 2 x 4 2 x 4 2 x 416 2 x 4 2 x 4 2 x 4 2 x 4 2 x 618 2 x 4 2 x 4 2
49、 x 4 2 x 6 2 x 620 2 x 4 2 x 4 2 x 6 2 x 6 2 x 622 2 x 4 2 x 6 2 x 6 2 x 6 2 x 624 2 x 4 2 x 6 2 x 6 2 x 6 2 x 6Table 3Minimum Rail Size for Double-Cleat Ladders3(Nominal-Dimension Lumber)Working Length (feet)Pitch (H/L)Vertical 1/10 1/8 1/6(3)1/4(3)12 or less 2 x 4 2 x 4 2 x 4 2 x 4 2 x 414 2 x 4 2 x 4 2 x 4 2 x 4 2 x 616 2 x 4 2 x 4 2 x 6 2 x 6 2 x 618 2 x 4 2 x 6 2 x 6 2 x 6 2 x 620 2 x 4 2 x 6 2 x 6 2 x 6 Note 222 2 x 4 2 x 6 2 x 6 2 x 6 Note 224 2 x 4 2 x 6 2 x 6 2 x 6 Note 2NOTES for Table 2 and 3:(1) Pitch is defined as H, the horizontal distance from base of ladder to s
