Fire resistance test utilising the general principles of ... · The scope of British Standard 476: Part 20: 1987 does not specifically include for the testing of cavity closers. However,

WFRC TEST REPORT NO. 134212

Fire resistance test utilising the general principles of BS 476: part 20 on four specimens of cavity

closer installed within simulated cavity wall and floor constructions

Warrington Fire Research Centre Ltd., Holmesfield Road, Warrington, UK WA1 2DS Tel: int + (0) 1925 655116 • Fax: int + (0) 1925 646616 • www.wfrc.co.uk•Reg.No. 1247124

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Summary Objective To evaluate the ability of specimens of a proprietary cavity closer system to

provide a fire stop within the cavity between the inner and outer leaf of an external cavity wall construction at a position where apertures have been provided for doors and windows. The test utilised the general principles for fire resistance testing given in BS 476: Part 20: 1987. `Methods for determination of the fire resistance of elements of construction (general principles).

Sponsor Manthorpe Building Products, Condor Gate Business Park, Ripley, Derbyshire, DE5 3ND.

Summary Of The Tested Specimen

The test construction comprised four specimens (referenced A to D for the purpose of the test) which were installed into simulated cavities, comprising aerated concrete facings of nominal dimensions 130 mm wide by 900 mm long.

The cavity closer was of overall dimensions 135 mm wide by 60 mm deep by900 mm long and comprised an extruded uPVC casing, encapsulating 50 mm thick mineral fibre based insulation. The main body of the closer was positioned within the cavity, with the uPVC casing overlapping the cavity wall. Each specimen was then clad on one face only with a section of PVC window frame, and a section of 12.5 mm thick plasterboard. This was to simulate a typical detail where the systems would be employed around an aperture containing a window.

Specimens A and B were installed into vertically orientated cavities, Specimen A was installed behind the window frame which was positioned over the unexposed cavity face. Specimen B was installed behind the window frame, which was positioned over the exposed cavity face.

Specimens C and D were installed into horizontally orientated cavities, Specimen C was installed behind the window sill which was positioned over the unexposed cavity face. Specimen D was installed behind the window sill which was positioned over the exposed cavity face.

Test Results: Specimen A Specimen B Specimen C Specimen D

Integrity 35 minutes 35 minutes 35 minutes 35 minutes

Insulation 35 minutes 35 minutes 35 minutes 35 minutes

The test was discontinued after a period of 35 minutes

Date of Test 18th September 2003

This report may only be reproduced in full. Extracts or abridgements of reports shall not be published without permission of Warrington Fire Research Centre.

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Signatories

Responsible Officer R. Wakefield* Technical Officer

Approved S. Hankey* Technical Consultant

* For and on behalf of Warrington Fire Research Centre. Report Issued Date : 28th October 2003

This copy has been produced from a .pdf format electronic file that has been provided by Bodycote warringtonfire to the sponsor of the report and must only be reproduced in full. Extracts or abridgements of reports must not be published without permission of Bodycote warringtonfire. The original signed paper version of this report is the sole authentic version. Only original paper versions of this report bear authentic signatures of the responsible Bodycote warringtonfire staff.

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CONTENTS PAGE NO.

SUMMARY.................................................................................................................................. 2

SIGNATORIES............................................................................................................................ 3

TEST PROCEDURE...................................................................................................................... 5

TEST SPECIMEN ........................................................................................................................ 6

SCHEDULE OF COMPONENTS .................................................................................................... 9

INSTRUMENTATION................................................................................................................ 11

TEST OBSERVATIONS.............................................................................................................. 12

TEST PHOTOGRAPHS............................................................................................................... 13

TEMPERATURE DATA............................................................................................................... 16

PERFORMANCE CRITERIA AND TEST RESULTS....................................................................... 22

ONGOING IMPLICATIONS....................................................................................................... 22

CONCLUSIONS ........................................................................................................................ 23

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Test Procedure Introduction The Building Regulations 1991, Requirement B3 (4) requires that a building shall

be designed and constructed so that the unseen spread of fire and smoke within concealed spaces in its structure and fabric is inhibited. Such sealing is effected by what are termed cavity barriers or cavity closers.

The scope of British Standard 476: Part 20: 1987 does not specifically include for the testing of cavity closers. However, the Regulations require that large cavity barriers should be tested to BS 476 as either vertical or horizontal separating elements, whichever is appropriate to their use. Similar test requirements apply to small cavity barriers which are not of the type specified within the Regulations, but the Department of the Environment has been sympathetic to the testing of these constructions at a reduced size or in a construction simulating their use in practice.

The specimens were judged on their ability to comply with the performance criteria for integrity and insulation, as required by BS 476: Part 20: 1987.

Fire Test Study Group/EGOLF

Certain aspects of some fire test specifications are open to different interpretations. The Fire Test Study Group and EGOLF have identified a number of such areas and have agreed Resolutions which define common agreement of interpretations between fire test laboratories which are members of the Groups. Where such Resolutions are applicable to this test they have been followed.

Instruction To test

The test was conducted on the 18th September 2003 at the request Manthorpe Building Products the sponsor of the test.

Mr. M Challinor, a representative of the test sponsor witnessed the test.

Test Specimen Construction

A comprehensive description of the test construction is given in the Schedule of Components. The description is based on a detailed survey of the specimens and information supplied by the sponsor of the test.

Installation The cavity closers were supplied by the sponsor during the week commencing 6th September 2003 and installed into the test construction by Warrington Fire Research Centre on the 16th September 2003. Warrington Fire Research Centre was not involved in any selection or sampling procedure of the specimens or any of the components.

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Test Specimen Figure 1- General Elevation Of Wall Specimen

Positions of thermocouples

6

1000 Furnace aperture

1000

Fur

nace

ape

rtur

e

A B

7

1110 1312

98

900

Spec

imen

s

2

4

1

3

Do not scale. All dimensions are in mm

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Figure 2 – Plan View Of Floor Specimen

1000 Furnace aperture

1000

Fur

nace

ape

rtur

e

1

21

20 18

19 17

16 14

15

900

Spec

imen

s

C D

5

3

2

Positions of thermocouples

Do not scale. All dimensions are in mm

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Figure 3 – Sections Though Wall & Floor Specimens

FIRE

35

2

35

3

2

4

3 4

1

1

2

2

FIRE

Do not scale. All dimensions are in mm

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Schedule of Components (Refer to Figures 1 to 3) (All values are nominal unless stated otherwise) (All other details are as stated by the sponsor) Item

Description

1. Wall & Floor Slabs Material : Autoclaved aerated concrete slabs Density : 670 kg/m3 Overall size : 150 mm x 250 mm 2. Cavity Closer Manufacturer : Manthorpe Building Products Ltd Reference : G249F Material i. casing : Extruded polyvinyl chloride (unplastisized) PVCu ii. insulation : Mineral fibre based insulation Thickness i. casing : 1.5 mm ii. insulation : 50 mm Density : 100 g/m3, stated, uncompressed Overall size : 135 mm wide x 60 mm deep x 900 mm long 3. Dry Lining Manufacturer : British Gypsum Reference : Wallboard Material : Gypsum based plasterboard Thickness : 12.5 mm Overall size : 150 mm x wide x 900 mm long Bedding material i. manufacturer : Dow Corning ii. material : Acrylic intumescent sealant iii. reference : Firestop 400 iv. application method : Cartridge gunned

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Item

Description

4. Window Frame Manufacturer : Eurocell Profiles Ltd Reference : EWS021 Material : Extruded polyvinyl chloride (unplastisized) PVCu Thickness : 2.2 mm – 2.9 mm Overall size : 70 mm x 62 mm x 900 mm long Bedding material i. manufacturer : Dow Corning ii. material : Acrylic intumescent sealant iii. reference : Firestop 400 iv. application method : Cartridge gunned 5. Window Cill Manufacturer : Eurocell Profiles Ltd Reference : AC150 Material : Extruded polyvinyl chloride (unplastisized) PVCu Thickness : 2 mm Overall size : 150 mm x 34 mm x 900 mm long Bedding material i. manufacturer : Dow Corning ii. material : Acrylic intumescent sealant iii. reference : Firestop 400 iv. application method : Cartridge gunned

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Instrumentation

General The instrumentation provided was in accordance with BS 476: Part 20: 1987 where appropriate.

Furnace The furnace was controlled so that its mean temperature complied with the requirements of BS 476: Part 20: 1987, Clause 3.1, using four mineral insulated thermocouples distributed over a plane 100 mm from the surface of the wall construction.

Thermocouple Allocation

Thermocouples were provided to monitor the unexposed surface of the specimens and the output of all instrumentation was recorded at no less than one minute intervals as follows:

The locations and reference numbers of the various unexposed surface thermocouples are shown in Figure 1.

Roving Thermocouple

A roving thermocouple was available to measure temperatures on the unexposed surface of the specimens at any position, which might appear to be hotter than the temperatures indicated by the fixed thermocouples.

Integrity criteria Cotton pads and gap gauges were available to evaluate the integrity of the specimens.

Furnace Pressure After the first five minutes of testing the furnace atmospheric pressure was controlled so that it complied with the requirements of BS 476: Part 20: 1987, Clause 3.2.2. The furnace atmospheric pressure 100 mm below the soffit of the floor slab was calculated to be 18 (± 2) Pa. The pressure at mid height of the wall slab was approximately 15 (± 2) Pa.

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Test Observations All observations are from the unexposed face unless noted otherwise

Mins Secs

00 00 The Test Commences.

02 30 E Flames have begun to issue from the plastic sill on Specimen D.

04 00 E The sill on Specimen D has fallen away.

06 00 E All areas of plastic on Specimens A and B have melted exposing the rockwool. The frame on Specimen B has begun to degrade and char.

06 30 Smoke issues from both ends of Specimens C and D.

09 30 Smoke issues from Specimen B.

15 00 E The window frame on Specimen B has begun to fall away. It is heavily charred and approximately only 50% remains in place.

17 00 The plastic shell has begun to soften near the head of Specimen B.

18 00 Smoke release continues to increase from Specimen D. The plastic shell has begun to blacken at the end where the greatest smoke release is.

20 00 The plastic shell at the head of Specimen B has begun to blacken at the head.

25 00 Specimen D has discoloured a yellowish colour due to the smoke release.

26 30 Smoke release has begun to increase from the head of Specimen A.

27 00 E The plasterboard on Specimen D has fallen away. The plasterboard on Specimen B is heavily cracked and has begun to fall away.

28 80 There is a slight area of glowing at the head of Specimen B where the shell has melted.

32 00 The plastic casing of Specimen D has begun to melt exposing the mineral wool core; areas of glowing are now visible.

35 00 The test is discontinued at the request of the sponsor.

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Test Photographs

The unexposed face of the test construction prior to testing

The unexposed face of the test construction prior to testing

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The unexposed face of the test construction during the test

The unexposed face of the test construction during the test

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The head of Specimen B during the test

Exposed face directly after removal from the furnace

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Temperature Data

Mean Furnace Temperature, Together With The Temperature/Time Relationship Specified In The Standard

Time Specified Actual Furnace Furnace Temperature Temperature

Mins Deg. C Deg. C 0 20 21 1 349 307 2 445 473 3 502 539 4 544 532 5 576 551 6 603 594 7 626 620 8 645 643 9 663 651 10 678 671 11 693 686 12 705 696 13 717 712 14 728 721 15 739 727 16 748 732 17 757 748 18 766 755 19 774 762 20 781 771 21 789 783 22 796 785 23 802 791 24 809 799 25 815 802 26 820 812 27 826 814 28 832 822 29 837 832 30 842 838 31 847 844 32 851 850 33 856 856 34 860 859 35 865 865

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Individual Temperatures Recorded On The Unexposed Surface Of Specimen A

Time T/C T/C T/C T/C Number Number Number Number 6 7 10 11

Mins Deg. C Deg. C Deg. C Deg. C 0 20 20 21 20 1 20 20 21 20 2 20 20 21 20 3 20 20 21 20 4 20 20 21 21 5 20 20 21 21 6 20 20 21 21 7 20 20 21 20 8 20 20 21 20 9 20 20 22 20 10 20 20 22 20 11 20 20 22 20 12 21 20 23 20 13 22 20 24 20 14 22 20 25 20 15 23 20 25 20 16 24 20 26 20 17 26 20 28 21 18 27 20 29 21 19 28 21 31 22 20 29 21 32 22 21 31 21 33 22 22 33 21 35 22 23 34 21 36 22 24 37 21 37 23 25 40 22 38 23 26 42 22 39 23 27 45 23 42 23 28 48 23 43 24 29 51 24 45 25 30 53 24 46 25 31 55 26 49 26 32 57 27 50 28 33 59 28 52 30 34 61 29 54 31 35 63 30 57 32

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Individual Temperatures Recorded On The Unexposed Surface Of Specimen B

Time T/C T/C T/C T/C Number Number Number Number 8 9 12 13

Mins Deg. C Deg. C Deg. C Deg. C 0 19 14 19 19 1 19 13 19 19 2 19 13 19 19 3 19 14 19 19 4 19 13 19 19 5 20 13 19 19 6 20 13 19 19 7 20 13 19 19 8 20 12 19 19 9 20 20 19 19 10 21 19 19 19 11 25 19 20 19 12 36 19 20 19 13 49 19 20 19 14 56 19 20 19 15 60 19 22 19 16 63 19 26 19 17 67 19 33 19 18 68 19 42 19 19 69 19 51 19 20 70 19 57 20 21 70 19 59 19 22 70 19 62 20 23 70 19 62 20 24 70 19 63 20 25 71 19 64 20 26 71 19 65 20 27 73 18 65 19 28 73 18 66 19 29 74 18 68 19 30 76 18 70 19 31 77 17 73 19 32 81 17 76 19 33 83 17 77 20 34 85 17 79 20 35 89 17 81 20

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Individual Temperatures Recorded On The Unexposed Surface Of Specimen C

Time T/C T/C T/C T/C

Number Number Number Number 18 19 20 21

Mins Deg. C Deg. C Deg. C Deg. C 0 21 21 20 20 1 21 21 21 20 2 21 21 20 20 3 21 21 20 21 4 21 21 20 20 5 21 21 20 20 6 21 21 20 20 7 21 21 20 20 8 21 21 20 20 9 21 21 20 20 10 21 21 20 20 11 22 22 20 21 12 22 22 20 21 13 23 22 20 21 14 23 23 20 21 15 24 23 21 20 16 25 25 21 21 17 25 25 22 21 18 26 26 22 21 19 27 27 23 21 20 28 27 23 21 21 29 28 25 21 22 31 30 25 22 23 32 31 27 22 24 33 32 28 22 25 36 33 29 22 26 38 33 30 22 27 41 35 31 23 28 44 36 32 23 29 46 37 33 23 30 48 38 33 24 31 49 39 34 24 32 50 40 35 24 33 51 42 35 25 34 52 43 36 25 35 54 44 36 25

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Individual Temperatures Recorded On The Unexposed Surface Of Specimen D

Time T/C T/C T/C T/C

Number Number Number Number 14 15 16 17

Mins Deg. C Deg. C Deg. C Deg. C 0 19 20 20 20 1 20 20 20 20 2 20 20 20 20 3 20 20 20 20 4 20 20 20 20 5 20 20 20 20 6 20 20 21 20 7 20 20 21 21 8 20 20 23 21 9 20 20 26 22 10 20 20 29 23 11 19 19 33 26 12 19 19 37 35 13 19 19 40 50 14 19 19 45 57 15 19 19 49 60 16 19 19 53 64 17 19 19 56 65 18 19 19 59 66 19 19 19 63 67 20 19 19 67 68 21 19 19 69 69 22 19 19 72 70 23 19 19 74 72 24 19 19 78 73 25 20 19 80 76 26 20 19 86 77 27 20 19 94 79 28 20 19 102 80 29 20 19 102 83 30 20 20 103 86 31 20 20 104 91 32 20 20 108 97 33 20 20 113 98 34 20 20 123 103 35 20 20 132 110

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Graph Showing Mean Furnace Temperature, Together with the Temperature/Time

Relationship Specified in the Standard

0

100

200

300

400

500

600

700

800

900

1000

0 5 10 15 20 25 30 35 40

Time - Minutes

Tem

pera

ture

- D

eg. C

Specified FurnaceTemperature Deg. CActual FurnaceTemperature Deg. C

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Performance Criteria and Test Results

Integrity It is required that there is no collapse of the specimen, no sustained flaming on the unexposed surface and no loss of impermeability. These requirements were satisfied for 35 minutes, the test duration.

Insulation The mean and maximum temperature rise allowable on the unexposed face of the specimen by BS 476: Part 20: 1987 are 140ºC and 180ºC respectively, however, due to the reduced size of the cavity closers only the maximum temperature rise criterion was utilised. These requirements were satisfied for 35 minutes the test duration.

Ongoing Implications Limitations The results relate only to the behaviour of the specimens of the elements of

construction under the particular conditions of test. They are not intended to be the sole criteria for assessing the potential fire performance of the element in use, nor do they reflect the actual behaviour in fires.

The test results relate only to the specimens tested. Appendix A of BS 476: Part 20: 1987 provides guidance information on the application of fire resistance tests and the interpretation of test data. Application of the results to cavity closers of different dimensions or installed in alternative cavity constructions or incorporating different components should be the subject of a design appraisal.

Review This report covers a test which was conducted to a procedure which is not the subject of any British Standard specification, but the test utilised the general principles of fire resistance testing given in BS 476: Part 20: 1987. Since fire tests are the subject of review and possible amendment and new interpretations, it is recommended that this report be referred back to the test laboratory after a period of two years to ensure that the methodology adopted and the results obtained remain valid in the light of the situation prevailing at that time.

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Conclusions Evaluation Against Objective

A fire test which utilised the heating conditions and performance criteria specified in BS 476: Part 20: 1987, has been conducted to evaluate the ability of four specimens of proprietary cavity closer system to provide a fire stop within the cavity between the leaves of an external wall construction at positions where apertures have been provided for windows or doorsets.

If the performance of each specimen was assessed against the performance requirements for integrity and insulation (maximum temperature rise) specified in BS 476: Part 20: 1987, the results obtained could be expressed as follows:

Test Results: Specimen A Specimen B Specimen C Specimen D

Integrity 35 minutes 35 minutes 35 minutes 35 minutes

Insulation 35 minutes 35 minutes 35 minutes 35 minutes

The test was discontinued after a period of 35 minutes