National foreword

This British Standard is the UK implementation of ISO 834‑1:2025.

The UK participation in its preparation was entrusted to Technical Committee FSH/22, Fire resistance tests.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2025.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 92, Fire Safety, Subcommittee SC 2, FireResistance.

This second edition cancels and replaces the first edition of ISO 834‑1:1999 and the second edition of ISO/TR 834‑3:2012, which have both been technically revised. It also incorporates the Amendment(s) ISO 834‑1:1999/Amd 1:2012 and ISO 834‑1:1999/Amd 2:2021.

The main changes are as follows:

the content has been aligned with EN 1363‑1: additional time-temperature curves have been added and changes have been made with respect to the criteria for load bearing capacity.

A list of all parts in the ISO 834 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

The main changes made in this document with respect to ISO 834‑1:1999/Amd2:2021 have been to align with EN 1363‑1. In that respect, additional time-temperature curves have been added, and changes have been made to the criteria for load bearing capacity. ISO/TC 92/SC 2 appreciates that such criteria are in essence a contemporary compromise between state of the art science on structural behaviour in fire, and considerations reflecting the practical implication for use in fire laboratories, respecting the safety of staff and protecting the test equipment. EN 1363‑1 was revised in 2019 (published officially in 2020), not directly based on scientific evidence but leaning more on practical considerations, with a view to judge different structures on a fair and equal basis, regardless of their failure mode in fire. Over the past couple of years, the revised EN 1363‑1 has been used satisfactorily in Europe. Taking good notice of this, and after good discussion, ISO/TC 92/SC 2, decided to adopt the EN 1363‑1:2020 changes.

1 Scope

This document specifies a test method for determining the fire resistance of various elements of construction when subjected to fire exposure conditions, represented with standardized time-temperature curves. The test data thus obtained will permit subsequent classification on the basis of the duration for which the performance of the tested elements under these conditions satisfies specified criteria.

2 Normative references

3 Terms and definitions

4 Symbols

5 Test equipment

5.1 General

5.2 Furnace

5.3 Loading equipment

5.4 Restraint and support frames

5.5 Instrumentation

5.6 Accuracy of measuring equipment

6 Test conditions

6.1 Furnace temperature

6.2 Furnace pressure differential

6.3 Loading

6.4 Restraint/boundary conditions

6.5 Ambient conditions

6.6 Deviation from specified test conditions

6.7 Calibration

6.8 Furnace atmosphere

7 Test specimen preparation

7.1 Construction

7.2 Size

7.3 Number of test specimens

7.4 Conditioning

7.5 Test specimen verification

8 Application of instrumentation

8.1 Temperature

8.2 Pressure

8.3 Deformation

8.4 Integrity

9 Test procedure

9.1 Restraint application

9.2 Load application

9.3 Commencement of test

9.4 Measurements and observations

9.5 Termination of test

10 Performance criteria

10.1 General

10.2 Specific performance criteria

11 Validity of the test

12 Expression of test results

12.1 Fire resistance

12.2 Performance criteria

12.3 Termination prior to failure

12.4 Expression of test result

13 Test report

Bibliography

BS ISO 834-1:2025

Fire-resistance tests. Elements of building construction - General requirements

Current

Published:

30 Jun 2025