Fire containment -- Elements of building construction

ISO 6944-1:2008 specifies a method for determining the fire resistance of vertical and horizontal ventilation ducts under standardized fire conditions. The test examines the behaviour of ducts exposed to fire from the outside (duct A) and fire inside the duct (duct B). It is intended that ISO 6944-1:2008 be used in conjunction with ISO 834-1. ISO 6944-1:2008 is not applicable to ducts whose fire resistance depends on the fire resistance performance of a ceiling, ducts containing fire dampers at points where they pass through fire separations, doors of inspection openings, unless included in the duct to be tested, two- or three-sided ducts, or the fixing of suspension devices to floors or walls. General guidance and background information are provided.

Endiguement du feu -- Éléments de construction

General Information

Status
Published
Publication Date
31-Mar-2008
Current Stage
6060 - International Standard published
Start Date
17-Mar-2008
Completion Date
01-Apr-2008
Ref Project

RELATIONS

Buy Standard

Standard
ISO 6944-1:2008 - Fire containment -- Elements of building construction
English language
32 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 6944-1
First edition
2008-04-15
Fire containment — Elements of building
construction —
Part 1:
Ventilation ducts
Endiguement du feu — Éléments de construction —
Partie 1: Conduits de ventilation
Reference number
ISO 6944-1:2008(E)
ISO 2008
---------------------- Page: 1 ----------------------
ISO 6944-1:2008(E)
PDF disclaimer

This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but

shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In

downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat

accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.

Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation

parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In

the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

COPYRIGHT PROTECTED DOCUMENT
© ISO 2008

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or

ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2008 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 6944-1:2008(E)
Contents Page

Foreword............................................................................................................................................................ iv

Introduction ........................................................................................................................................................ v

1 Scope ......................................................................................................................................................1

2 Normative references ............................................................................................................................2

3 Terms and definitions ...........................................................................................................................2

4 Apparatus ...............................................................................................................................................2

5 Test conditions ....................................................................................................................................10

6 Test specimen......................................................................................................................................10

7 Installation of test specimen ..............................................................................................................13

8 Conditioning.........................................................................................................................................15

9 Application of instrumentation...........................................................................................................16

10 Test procedure.....................................................................................................................................22

11 Performance criteria............................................................................................................................23

12 Test report ............................................................................................................................................24

13 Field of direct application of test results ..........................................................................................25

Annex A (informative) General guidance........................................................................................................28

Bibliography ......................................................................................................................................................32

© ISO 2008 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 6944-1:2008(E)
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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 6944-1 was prepared by Technical Committee ISO/TC 92, Fire safety, Subcommittee SC 2, Fire

containment.

This first edition of ISO 6944-1, cancels and replaces ISO 6944:1985, which has been technically revised.

ISO 6944 consists of the following parts, under the general title Fire containment — Elements of building

construction:
⎯ Part 1: Ventilation ducts
A Part 2, dealing with kitchen extract ducts, is under development.
iv © ISO 2008 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 6944-1:2008(E)
Introduction

The purpose of this test is to measure the ability of a representative duct or duct assembly that is part of an

air-distribution system to resist the spread of fire from one fire compartment to another, with fire attack from

inside or outside the duct. It is applicable to vertical and horizontal ducts, with or without branches, taking into

account joints and exhaust openings, as well as suspension devices and penetration points.

This part of ISO 6944 is very similar to EN 1366-1, but includes an alternative arrangement for testing elbows.

The test measures the length of time during which ducts of specified dimensions, suspended as they normally

are in practice, satisfy defined criteria when exposed to fire from either inside or outside the duct.

All ducts inside the furnace are fully restrained in all directions. Outside the furnace, ducts exposed to fire from

the outside are tested unrestrained, while ducts exposed to fire from the inside (horizontal only) are tested

restrained.

The test takes into account the effect of fire exposure from the outside, where a 300 Pa underpressure is

maintained in the duct, as well as the effect of fire entering the ducts under conditions where forced air

movement might or might not be present, by maintaining an air velocity of 3 m/s.

Ducts exposed to fire from the inside are supplied with air in a manner that is representative of the “fan off”

and “fan on” situations that can arise in practice.
© ISO 2008 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 6944-1:2008(E)
Fire containment — Elements of building construction —
Part 1:
Ventilation ducts

CAUTION — The attention of all persons concerned with managing and carrying out this fire

resistance test is drawn to the fact that fire testing can be hazardous and that there is the possibility

that toxic and/or harmful smoke and gases can be evolved during the test. Mechanical and operational

hazards can also arise during the construction of the test elements or structures, their testing and

disposal of test residues.

It is strongly recommended that the duct assembly be allowed to cool completely after the fire test,

before dismantling, to minimize the possibility of ignition of combustible residues.

An assessment of all potential hazards and risks to health shall be made and safety precautions shall

be identified and provided. Written safety instructions shall be issued. Appropriate training shall be

given to relevant personnel. Laboratory personnel shall ensure that they follow written safety

instructions at all times.
1 Scope

This part of ISO 6944 specifies a method for determining the fire resistance of vertical and horizontal

ventilation ducts under standardized fire conditions. The test examines the behaviour of ducts exposed to fire

from the outside (duct A) and fire inside the duct (duct B). It is intended that this part of ISO 6944 be used in

conjunction with ISO 834-1.
This part of ISO 6944 is not applicable to

a) ducts whose fire resistance depends on the fire resistance performance of a ceiling,

b) ducts containing fire dampers at points where they pass through fire separations,

c) doors of inspection openings, unless included in the duct to be tested,
d) two- or three-sided ducts,
e) the fixing of suspension devices to floors or walls.
NOTE Annex A provides general guidance and gives background information.
© ISO 2008 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 6944-1:2008(E)
2 Normative references

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the referenced

document (including any amendments) applies.

ISO 834-1, Fire-resistance tests — Elements of building construction — Part 1: General requirements

ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-

section conduits running full — Part 1: General principles and requirements

ISO 5221, Air distribution and air diffusion — Rules to methods of measuring air flow rate in an air handling

duct
ISO 13943, Fire safety — Vocabulary
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 834-1 and ISO 13943, and the

following apply.
3.1
fire resisting duct

duct used for the distribution or extraction of air and designed to provide a degree of fire resistance

3.2
suspension device

components used for supporting and fixing a duct from a floor or supporting a duct from a wall

3.3
supporting devices
wall, partition or floor through which the duct passes during the test
3.4
compensator
device that is used to prevent damage from the forces generated by expansion
4 Apparatus

4.1 In addition to the test equipment specified in ISO 834-1, the following apparatus is required.

4.2 Furnace, capable of subjecting ventilation ducts to the standard heating conditions specified in

ISO 834-1 and suitable for testing ducts in the vertical (see Figure 1) or horizontal (see Figure 2) orientation.

Figures 1 and 2 show two ducts being tested together. When two ducts are tested together, they shall be

separated by a minimum of 500 mm. It is also permitted to test each duct singularly in the furnace.

4.3 Fan A, capable of producing an underpressure of (300 ± 15) Pa within duct A (see Figure 3) at the start

and throughout the test, and shall be connected, either directly or by a suitable length of flexible ducting, to the

measuring station (4.5).

4.4 Fan B, capable of producing an air velocity when extracting gas from duct B (see Figure 4) of at least

3 m/s measured at ambient temperature in the duct before the test.

It shall be connected, either directly or by a suitable length of flexible ducting, to the velocity-measuring station

(4.8). The fan shall be provided with a by-pass vent that can be opened prior to shutting the damper (4.7).

2 © ISO 2008 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 6944-1:2008(E)
Dimensions in millimetres
Key
1 7
furnace wall furnace chamber
2 8
sealed end openings providing a total area of 50% of duct cross-section
fire-protection system 9 furnace floor

location for fire stopping (normal practice) 10 leakage-measuring station (see Figure 3 for details)

joint in fire-protection system 11 gas-velocity-measuring station (see Figure 4 for details)

furnace roof 12 duct A
13 duct B
width
height
diameter
See 4.2.
Figure 1 — Test arrangement for vertical ducts
© ISO 2008 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 6944-1:2008(E)
Dimensions in millimetres
Key
1 furnace wall 9 duct B
2 duct with 90° elbow 10 supporting construction
3 sealed end 11 furnace chamber
4 location for fire stopping (normal practice) 12
openings providing a total area of 50 % of duct cross-section
5 fire-protection system 13 sealed end of elbow
6 location of restraint positions 14
200 mm minimum supporting construction

7 joints in fire-protection system 15 leakage-measuring station (see Figure 3 for details)

8 duct A 16
gas-velocity-measuring station (see Figure 4 for details)
W width or diameter
See 4.2.
Figure 2 — Test arrangement for horizontal ducts
4 © ISO 2008 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 6944-1:2008(E)
Figure 3 (continued)
© ISO 2008 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 6944-1:2008(E)
Key
1 pressure sensor to furnace 11 flexible connecting duct
2 pressure sensor on centre-line of duct 12 support for flow-measuring system
3 office plate, venture or similar 13 thermocouple, 1,5 mm diameter
4 14 flow straightener (where necessary)
pressure differential of 300 Pa
5 pressure sensor in laboratory 15 flange
6 pressure-differential control box 16 support for duct outside furnace
7 pressure-control dilution damper 17 test duct
8 pneumatic-actuator manual control 18 condensing device
9 balancing damper 19
horizontal duct A
10 fan 20
vertical duct A
Thermocouple located 2d from key item 3; see Note.

NOTE d is the diameter of the measuring duct downstream from the flow-measuring device.

Figure 3 — Leakage-measuring station for duct A
6 © ISO 2008 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 6944-1:2008(E)
Figure 4 (continued)
© ISO 2008 – All rights reserved 7
---------------------- Page: 12 ----------------------
ISO 6944-1:2008(E)
Key
pressure sensor to furnace 11 thermocouple, 1,5 mm diameter

pressure sensor on centre-line of duct 12 support for velocity-measuring station near duct

pressure sensor in laboratory 13 flange
pressure-differential control box 14 support for duct outside furnace
pressure-control dilution damper 15 inlet nozzle
pneumatic-actuator manual control 16 test duct
balancing damper 17 flow straightener (if required)
fan 18 horizontal duct A
flexible connecting duct 19 vertical duct A

support for velocity-measuring station near flexible duct 20 pressure differential of 300 Pa

Figure 4 — Gas velocity station for duct B

4.5 Volume flow-measuring station, consisting of a venturi, orifice plate or other suitable device and

(where necessary) an air-flow straightener, installed in straight lengths of pipe, all sized to ISO 5167-1 and

ISO 5221.

It shall be connected to the end of duct A outside the furnace to determine the volume flow rate of gas passing

through duct A during the test. The measuring device shall be capable of measuring to an accuracy of ± 5 %.

Regardless of whether vertical or horizontal ducts are being tested, the volume flow-measuring station shall

always be used in a horizontal orientation.

4.6 Condensing unit, installed between the end of duct A and the flow-measuring device and which shall

allow for drainage.

The gas temperature adjacent to the flow-measuring device shall be measured by a 2 mm sheathed

thermocouple with an insulated hot junction, arranged pointing downwards to allow the moisture to drain. Its

measuring junction shall be located at the centre-line of the measuring duct and at a distance, d, equal to

twice the diameter of the measuring duct downstream from the flow-measuring device. The temperature

measured by this thermocouple shall not exceed 40 °C.

4.7 Damper, installed between the fan and the velocity-measuring station to shut off the air flow in duct B

during evaluation of integrity in the “fan off” condition.

4.8 Velocity-measuring station, to determine the air velocity in duct B and shall consist of one or two inlet

nozzle(s), or another suitable device, installed in a straight length of pipe sized to ISO 5167-1 and ISO 5221,

connected to the end of both the vertical and horizontal ducts B outside the furnace.

4.9 Equipment for measuring gas pressure, located in the furnace and inside duct A.

4.10 Thermal-movement-measuring device, for measuring the expansion or contraction of duct A,

accurate to ± 1 mm.

4.11 Force-measuring device, for measuring forces at the point of applying the restraint in duct B (see

Figure 5).
8 © ISO 2008 – All rights reserved
---------------------- Page: 13 ----------------------
ISO 6944-1:2008(E)
Dimensions in millimetres
Key
1 location of device measuring the restraining forces
2 duct
3 stiff load cells (used for applying and measuring restraint)
4 furnace
Allow movement in both directions.
Resist movement in both directions.
Figure 5 — Restraint of duct B outside the furnace
© ISO 2008 – All rights reserved 9
---------------------- Page: 14 ----------------------
ISO 6944-1:2008(E)
5 Test conditions

The heating conditions and the furnace atmosphere shall conform to those given in ISO 834-1.

The furnace pressure shall be controlled to (15 ± 3) Pa throughout the test at the mid-height position of the

ducts.

Details of test conditions within the ducts during the test are given in Clause 10.

6 Test specimen
6.1 Size
6.1.1 General

Ducts of sizes other than those given in Tables 1 and 2 have restricted the field of direct application (see

Clause 13).
6.1.2 Length

The minimum lengths of the parts of the test specimen inside and outside the furnace shall be as given in

Table 1 (see also Figures 1 and 2).
Table 1 — Minimum length of test specimen
Minimum length
Orientation
Inside the furnace Outside the furnace
Horizontal 4,0 2,5
Vertical 2,0 2,0
6.1.3 Cross-section

The standard sizes of ducts given in Table 2 shall be tested unless only smaller cross-sections are used.

Table 2 — Cross-sectional dimensions of test specimen
Rectangular Circular
Duct
width height diameter
mm mm mm
A 1 000 ± 10 500 ± 10 800 ± 10
1 000 ± 10 250 ± 10 630 ± 10
6.2 Number
One test specimen shall be tested for each type of installation being evaluated.
10 © ISO 2008 – All rights reserved
---------------------- Page: 15 ----------------------
ISO 6944-1:2008(E)
6.3 Design
6.3.1 General

The test shall be made on a test specimen representative of the complete duct assembly on which information

is required. The edge conditions and the method of fixing or support inside and outside the furnace shall be

representative of those used in normal practice.
Ducts shall be arranged as shown in Figures 1 and 2.
6.3.2 Minimum separation

There is no limit to the number of ducts that may be tested simultaneously in the same furnace, provided that

there is a minimum space of 500 mm between the ducts, in accordance with the dimensions shown in

Figures 1 and 2.

There shall be a separation of (500 ± 50) mm between the top of a horizontal duct and the ceiling. A minimum

separation of 500 mm shall be provided between the underside of a horizontal duct and the floor. Similarly,

there shall be a minimum separation of at least 500 mm between the sides of ducts and the furnace walls.

6.3.3 Configuration of duct A (horizontal only)

The horizontal duct A shall include one sharp bend, a T-piece and a 500 mm long length of duct forming a

short branch duct having a cross-section of 250 mm × 250 mm, and shall be arranged as shown in Figure 2.

All specimens, including this branch, shall be mounted with the suspension or fixing devices as intended in

normal practice.

An alternative test arrangement where the elbow in horizontal duct A is replaced by a vertical section of duct,

which passes through the furnace roof and is then connected to the measuring system and the fan, is

illustrated in Figure 6.
6.3.4 Openings in duct B

Two openings shall be provided, one on each vertical side of the duct inside the furnace. For horizontal ducts,

the openings shall be positioned (500 ± 25) mm from the furnace wall. For vertical ducts, the openings shall

be positioned (200 ± 10) mm below the furnace roof. (See Figures 1 and 2.)

In both vertical and horizontal ducts, the openings shall have the same breadth-to-height ratio as the cross-

section of the duct and a total opening area of (50 ± 10) % of the cross-sectional area of the duct, i.e. each

opening shall have an area of (25 ± 5) % of the cross-sectional area of the duct.

6.3.5 Joints in horizontal ducts

The test configuration shall include at least one joint inside and at least one joint outside the furnace.

There shall be at least one joint per layer of fire-protection material, both inside and outside the furnace and in

any steel duct.

Outside the furnace, the joint in the outer layer of the fire-protection material shall be no further than 700 mm

from the supporting construction and no nearer than 100 mm to thermocouples T2; see Figures 10 to 12.

Inside the furnace, the joint in the outer layer of fire-protection material shall be located at approximately

mid-span.

The distance between joints and suspension devices shall not be less than that used in practice. If the

minimum distance has not been specified, suspension devices shall be arranged so that the joint at mid-span

lies midway between them. Centres of the suspension devices shall be specified by the manufacturer and

shall be representative of practice.
© ISO 2008 – All rights reserved 11
---------------------- Page: 16 ----------------------
ISO 6944-1:2008(E)
Dimensions in millimetres
Key
1 duct with vertical elbow 7 location of restraint positions
2 furnace roof/supporting construction 8 sealed end
3 fire-protection system 9 joints in fire-protection system
4 location for fire stopping (normal practice) 10 furnace wall
5 11 furnace chamber
connection of elbow to measuring system and fan as shown in Figure 3
6 duct supports (normal practice)
Figure 6 — Alternative arrangement for duct A with vertical elbow
6.3.6 Joints in vertical ducts

The test configuration shall include at least one joint inside and one joint outside the furnace (see Figure 1).

There shall be at least one joint for every layer of fire-protection material, both inside and outside the furnace

and in any steel duct.

Outside the furnace, the joint in the outer layer of the fire-protection material shall be no further than 700 mm

from the supporting construction and no nearer than 100 mm to the thermocouples T2; see Figures 10 to 12.

Inside the furnace, the joint in the outer layer of fire-protection material shall be located at approximately

mid-span.
6.3.7 Support for vertical ducts

Vertical ducts shall be supported on the furnace floor and shall penetrate through the furnace roof

slab/supporting construction (see Figure 1); the ducts shall be fixed at the furnace-roof level as they are

normally fixed in practice when penetrating a floor. This shall be as specified by the sponsor.

12 © ISO 2008 – All rights reserved
---------------------- Page: 17 ----------------------
ISO 6944-1:2008(E)
6.3.8 Compensators

Only where compensators are normally used in practice shall they be incorporated in the test specimen.

Where a compensator is being tested, it shall be located within the furnace for duct A and, for duct B, outside

the furnace approximately 500 mm from the wall or floor.
7 Installation of test specimen
7.1 General

The test specimen shall be installed, as far as possible, in a manner representative of its use in normal

practice.

The supporting construction selected shall be a wall, partition or floor of the type used in normal practice and

shall have a fire resistance greater than the required fire resistance of the duct being tested.

Where the duct passes through an opening in the furnace wall or roof, the opening shall be of sufficient

dimensions that the minimum distance between the edge of the fire stopping (see 7.4.5) adjacent to the

supporting construction and the outside perimeter of the supporting construction is 200 mm (see Figure 7).

Key
1 furnace wall or furnace roof
2 fire stopping
3 supporting construction
4 duct
The dimension A shall be a minimum of 200 mm.

Figure 7 — Details of duct passing through an opening in the furnace wall or roof

© ISO 2008 – All rights reserved 13
---------------------- Page: 18 ----------------------
ISO 6944-1:2008(E)
7.2 Standard supporting construction

Where the type of supporting construction used in normal practice is not known, then one of the standard

supporting constructions described in Tables 3 to 5 shall be used.
Table 3 — Standard rigid-wall constructions
Type of Thickness Density Test duration
construction t
kg/m
Normal concrete/masonry t = 2
110 ± 10 2 200 ± 200
150 ± 10 2 200 ± 200 2 < t u 3
175 ± 10 2 200 ± 200 3 < t u 4
Aerated concrete 110 ± 10 650 ± 200 t = 2
150 ± 10 650 ± 200 2 < t u 4

This supporting construction may be made from blocks bonded together with mortar or adhesive.

Table 4 — Standard flexible-wall constructions (gypsum plasterboard)
Fire resistance Wall constructions
a b
Number of layers Thickness
Insulation Thickness
min on each side
D/ρ mm
30 1 12,5 40/40 75
60 2 12,5 40/40 100
90 2 12,5 60/50 125
120 2 12,5 60/100 150
180 3 12,5 60/100 175
240 3 15,0 80/100 190
a 3

D is the thickness in mm of mineral wool insulation inside the wall; ρ is the density in kg/m of mineral wool insulation inside the

wall.
Tolerance of ± 10 %.
Table 5 — Standard floor constructions
Type of Thickness Density Test duration
construction t
kg/m
Normal concrete
110 ± 10 2 200 ± 200 t = 1,5
150 ± 10 2 200 ± 200 1,5 < t u 3
3 < t u 4
175 ± 10 2 200 ± 200
Aerated concrete
t = 2
125 ± 10 650 ± 200
150 ± 10 650 ± 200 2 < t u 4
14 © ISO 2008 – All rights reserved
---------------------- Page: 19 ----------------------
ISO 6944-1:2008(E)
7.3 Non-standard supporting constructions

When the test specimen is intended for use in a form of construction not covered by the standard supporting

constructions, it shall be tested in the supporting construction intended for use.

7.4 Restraint of ducts
7.4.1 Inside the furnace

All ducts shall be fully restrained in all directions at the furnace wall or floor remote from the penetration point.

Where there is a possibility of movement of the furnace wall, the fixings shall be made independent of the

furnace structure.
7.4.2 At the penetration point

Where, in practice, the duct is fixed at floor level, then both vertical ducts A and B shall be fixed where the

duct penetrates the furnace roof/supporting construction as specified by the sponsor.

7.4.3 Outside the furnace

Only horizontal duct B shall be restrained outside the furnace. The restraining point shall be located at a

position (2 000 ± 50) mm from the furnace wall and shall provide restraint on movement in the horizontal

directions but shall allow movement in the vertical directions (see Figure 5). The frame used to apply the

restraint shall be rigid and have sufficient strength to resist all horizontal forces. All other ducts shall be

unrestrained outside the furnace.
7.4.4 Closure

The end of the ducts within the furnace and the end of any branch duct attached shall be closed

independently of any furnace enclosure, by materials and construction similar to the remainder of the duct.

7.4.5 Fire stopping

The fire stopping at the penetration through the supporting construction shall be as intended in practice. If the

width of the gap for fire-stopping around the duct at the furnace penetration point is not specified, a width of

50 mm shall be used.
7.4.6 Unsupported vertical ducts

Where, in practice, vertical ducts are not fixed to each floor, then the test specimen shall be suitably loaded to

simulate the weight of the remaining height of unsupported ducting.
8 Conditioning
8.1 General
Conditioning of the test construction shall be in accordance with ISO 834-1.
8.2 Hygroscopic sealing materials

Hygroscopic materials used to seal the gap between the supporting construction and the duct where the gap

is u 10 mm wide shall be conditioned for seven days before fire testing.

Hygroscopic materials used to seal the gap between the supporting construction and the duct assembly where

the gap is > 10 mm wide shall be conditioned for 28 days before fire testing.
© ISO 2008 – All rights reserved
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.