BS-6375-1-2009-Performance-of-windows-and-doors-–-Part-1-Classification-for-weathertightness-and-guidance-on-selection-and-specification

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Performance of windows anddoors –

Part 1: Classification for weathertightness andguidance on selection and specification

BS 6375-1:2009


NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

BSI British Standards

Publishing and copyright informationThe BSI copyright notice displayed in this document indicates when the document was last issued

© BSI 2008

ISBN 978 0 580 56202 0

ICS 91.060.50

The following BSI references relate to the work on this standard:Committee reference B/538/1+2Draft for comment 08/30143162 DC

Publication historyFirst published April 1989Second edition, April 2004Third (present) edition, December 2008

Amendments issued since publication

Date Text affected

BRITISH STANDARDBS 6375-1:2009

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Contents

Foreword iii

1 Scope 12 Normative references 13 Terms and definitions 14 Exposure category and classification 25 Sequence of test 26 Test for air permeability 37 Test for watertightness 48 Test for resistance to wind 6

AnnexesAnnex A (normative) Calculating wind load and selecting exposurecategory 7Annex B (informative) Flow chart of sequence of test 13Annex C (informative) Derivation of the wind load in Table A.2 14

Bibliography 16

List of figuresFigure 1 – Air permeability classifications 5Figure A.1 – Basic wind speed map Vb (from BS 6399-2) 8Figure A.2 – Topographic zones 12Figure B.1 – Flow chart of sequence of test 13

List of tablesTable 1 – Exposure categories and classifications 3Table A.1 – Site terrain categories 9Table A.2 – Wind load at sea level 10Table A.3 – Table for factor FA for specific altitudes 11Table A.4 – Topographical factor 11Table C.1 – Terrain and building factor Sb 14

Summary of pages

This document comprises a front cover, an inside front cover, pages ito iv, pages 1 to 16, an inside back cover and a back cover.

BS 6375-1:2009BRITISH STANDARD

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BS 6375-1:2009 BRITISH STANDARD

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Foreword

Publishing information

This part of BS 6375 is published by BSI and came into effect on1 January 2009. It was prepared by Subcommittee B/538/1, Windows,and Subcommittee B/538/2, Doors, under the authority of TechnicalCommittee B/538, Doors, windows, shutters, hardware and curtainwalling. A list of organizations represented on these committees canbe obtained on request to their secretary.

Supersession

This part of BS 6375 supersedes BS 6375-1:2004, which is withdrawn.

Relationship with other publications

BS 6375 is published in three parts:

* Part 1: Classification for weathertightness and guidance onselection and specification;

* Part 2: Specification for operation and strength characteristics;

* Part 3: Additional performance characteristics.

It is related to the European product standard for windows andpedestrian doors, BS EN 143511) (see also Information about thisdocument).

Information about this document

This is a full revision of the standard, and introduces the followingprincipal changes:

* revision of the foreword to align with Parts 2 and 3;

* clarification of the air permeability tests and requirements;

* tests previously required by PAS 23-1 for entrance doorsets havebeen included. It is expected that PAS 23-1 will be withdrawn.

BS 6375 has been prepared to provide advice on the selection ofperformance characteristics for windows and doorsets intended forthe UK market. The full range of characteristics is also provided in thevarious parts of BS EN 14351.

BS EN 14351 is the harmonized European Standard for windows anddoors and is the standard that has to be referenced if the product is tobe CE marked. Not all the characteristics listed in BS EN 14351 arerequired for CE marking, and of those that are required, only thosemandated (i.e. covered by national building regulations) in the UKneed be declared.

The majority of characteristics identified in BS EN 14351 have anumber of performance levels. BS 6375 provides guidance to thespecifier and the manufacturer on an appropriate level for the UKmarket. This can be by a single value for a product characteristic or bya value for a particular service condition. For example, a doorset in apublic building might need to meet a more severe level ofperformance for some characteristics than a doorset in a dwelling.

1) Only the first part of BS EN 14351 has been published to date.Part 2 (Internal doors) and Part 3 (Resistance to fire and smoke) are still inpreparation.


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Specifiers are not obliged to use a particular performance level butneed to be aware that unnecessarily selecting a more severeperformance level can incur a cost penalty out of proportion to theperformance advantage.

BS EN 14351 and BS 6375 cover a range of products and characteristicsand are therefore divided into parts. BS EN 14351 is divided intoproduct groups and BS 6375 is divided into performancecharacteristics. Not all characteristics will be applicable to all productgroups or to all end uses. In addition, BS 6375 may be used for productgroups not covered by BS EN 14351.

BS 6375 does not identify a recommended performance level for anycharacteristic that is recommended in national regulations (e.g.U values for windows); these levels are subject to statute.

If a manufacturer wishes to declare a CE marked performance this hasto be declared against the appropriate part of BS EN 14351.Manufacturers wishing to CE mark products are advised to seek advicefrom the relevant national regulatory authority.

Presentational conventions

The provisions of this standard are presented in roman (i.e. upright)type. Its requirements are expressed in sentences in which the principalauxiliary verb is ‘‘shall’’.

Commentary, explanation and general informative material ispresented in smaller italic type, and does not constitute a normativeelement.

Contractual and legal considerations

This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication.

Compliance with a British Standard cannot confer immunity fromlegal obligations.


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1 ScopeBS 6375 is the national application document for BS EN 14351. Thispart of BS 6375 specifies the exposure categories related to testpressure levels for air permeability, watertightness and wind resistancefor external windows and doorsets. It is applicable to all types ofvertical windows and doorsets, and includes windows in which theopening lights are not fully framed, e.g. adjustable glass louvres. It isapplicable to both factory-glazed and site-glazed products.

NOTE Recommendations for thedesign and installation of patentglazing are given in BS 5516.

The standard excludes patent glazing (see Note) and curtain walls thatspan across horizontal structural members of floors, but includes theopening lights within a vertical patent glazing or curtain wallingsystem.

2 Normative referencesThe following referenced documents are indispensable for theapplication of this document. For dated references, only the editioncited applies. For undated references, the latest edition of thereferenced document (including any amendments) applies.

BS 6399-2:1997, Loading for buildings – Part 2: Code of practice forwind loads

BS EN 1026, Windows and doors – Air permeability – Test method

BS EN 1027:2000, Windows and doors – Watertightness – Test method

BS EN 12207:2000, Windows and doors – Air permeability –Classification

BS EN 12208, Windows and doors – Watertightness – Classification

BS EN 12210, Windows and doors – Resistance to wind load –Classification

BS EN 12211, Windows and doors – Resistance to wind load – Testmethod

BS EN 14351 (all parts), Windows and doors – Product standard,performance characteristics2)

3 Terms and definitionsFor the purposes of this part of BS 6375, the following terms anddefinitions apply.

3.1 design height (H)NOTE In the case of a dormerwindow, this is the building ridgeheight.

maximum height of a wall in which a window or doorset occurs

3.2 doorsetNOTE This is also known as a doorassembly.

complete unit, as installed, comprising door leaf, door frame, anyassociated side panels and/or top lights, and any operating hardware,locks and accessories

2) Only the first part of BS EN 14351 has been published to date.Part 2 (Internal doors) and Part 3 (Resistance to fire and smoke) are still inpreparation.


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3.3 ventilation deviceNOTE The ‘‘permanent’’ typeprovides continuous ventilation.The ‘‘controlled’’ type is adjusted toprovide a range of ventilation.

ventilator other than an opening light incorporated in a window ordoorset

3.4 water penetrationNOTE Retention of water withinthe window or doorset system isnot defined as leakage.

continuous or repeated wetting of the internal surface of the testspecimen or parts which are not designed to be wetted when waterdrains back to external face[BS EN 1027]

3.5 weathertightnessperformance in respect of air permeability, watertightness and windresistance

3.6 wind loadpeak gust wind pressure that can be expected on a surface of abuilding window or doorset

4 Exposure category and classificationNOTE The classifications given inTable 1 are those suitable for theUK selected from BS EN 12207,BS EN 12208 and BS EN 12210.

The exposure category of a window or doorset shall be classified inaccordance with Table 1. For a window or doorset to be included in anexposure category, the test pressure for each relevant characteristicshall be attained or exceeded.

Doorsets that are tested and classified with a wind load greaterthan 1 200 shall be classified in accordance with BS EN 12207,BS EN 12208 and BS EN 12210.

5 Sequence of testNOTE A flow chart indicating thesequence of test is given in Annex B.

The tests shall be performed on a single sample in the followingsequence:

a) air permeability (see Clause 6);

b) watertightness (see Clause 7);

c) resistance to wind – deflection measurement at pressureP1 (see Clause 8);

d) resistance to wind – pulsating test to P2 pressure (see Clause 8);

e) resistance to wind – safety test to pressure P3 (see Clause 8).


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6 Test for air permeability

NOTE To establish airleakage through the windowor doorset and controllablevent (in the closed position),the air permeability test can berepeated with the vent closedbut not taped. This informationshould be included in the testreport.

6.1 For classification purposes, permanent and controlled ventilationdevices (including letterplates), if any, shall be taped over except whenit is required to determine the amount of air flow through suchdevices.

6.2 The specimen shall be tested in accordance with BS EN 1026 andthe test shall be conducted with both positive and negative pressures.The test result, defined as the numerical average of the positive andnegative air permeability values (m3/h) at each pressure step, shall beexpressed and classified in accordance with BS EN 12207. Classificationlevels applicable in the UK shall be in accordance with Table 1.

6.3 The air flow passing through the specimen, at each pressuredifference applied in accordance with BS EN 1026, shall be expressedas an average leakage rate per metre length of opening joint visibleon the inner face of the specimen and average leakage per metresquare of window area.

Table 1 Exposure categories and classifications

UK exposurecategories A), B)

Air permeability(see Clause 6)

Watertightness(see Clause 7)

Resistance to wind load (see Clause 8)

Class C) Maximumtest pressure

Class Maximumtest pressure

Class D) P1 P2 E) P3

Doorsets

800 U Class 0 No test Class 0 No test Class A2 800 Pa 400 Pa 1 200 Pa

800 X Class 1 150 Pa Class 2A 50 Pa Class A2 800 Pa 400 Pa 1 200 Pa

800 Class 2 300 Pa Class 3A 100 Pa Class A2 800 Pa 400 Pa 1 200 Pa

1 200 Class 2 300 Pa Class 3A 100 Pa Class A3 1 200 Pa 600 Pa 1 800 Pa

Windows

800 Class 2 300 Pa Class 3A 100 Pa Class A2 800 Pa 400 Pa 1 200 Pa



2 000 Class 2 300 Pa Class 5A 200 Pa Class A5 2 000 Pa 1 000 Pa 3 000 Pa

2 000 + Class 2 300 Pa Class 7A 300 Pa Class AE (xxxx) (xxxx) �0.5

(xxxx) �1.5

For the purpose of selecting the appropriate exposure category the following procedure shall be used.a) Calculate the wind load for the given location (see Annex A).b) Select the exposure category (see Table 1) equal to or exceeding the determined wind load.

NOTE Specimens tested with wind load above Class 5 are classified Class E xxxx – where xxxx is the actual test pressureP1 (e.g. when P1 = 2 350 Pa this is classified as Class E 2 350, etc.).

A) UK exposure category is specified by the design wind load, calculated in accordance with Annex A.B) Products designed to meet the accessibility requirements of UK building regulations are unlikely to exceed

category 800 X.C) Air permeability test pressures above Class 2 (up to 600 Pa) are available when stringent levels of performance are

required, for example when exceptionally airtight windows or doorsets are necessary, as in air-conditionedbuildings.

D) Combination of test pressure and frame deflection (see BS EN 12210).E) This pressure having been repeated 50 times.


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6.4 A graph of air permeability rate against test pressure differenceshall be constructed, including positive, negative and average results.The average values shall not exceed those in the appropriate graph inFigure 1. Fixed lights alone shall be classified by air permeability basedon overall area.

6.5 If the second test for air permeability (following the test forresistance to wind in Clause 8) results in air permeability that wouldplace the window or doorset in a lower classification, that lowerclassification shall be used to define the final classification of thewindow or doorset. A second graph shall then be constructed inaccordance with 6.4, and the average values shall not exceed those inthe appropriate graph in Figure 1.

7 Test for watertightness

NOTE To establish whetherthe ventilation device iswatertight, the test can berepeated with the vent closedbut not taped. This informationshould be included in the testreport.

7.1 For classification purposes, permanent and controlled ventilationdevices (including letterplates) shall be taped over.

7.2 The specimen shall be tested in accordance with BS EN 1027:2000,test procedure A and classified in accordance with BS EN 12208.Classification levels applicable in the UK shall be in accordance withTable 1.

7.3 There shall be no water penetration during the test, up to and at,the required test pressure class given in Table 1.


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Figure 1 Air permeability classifications

100 25

20

15

10

12.5

0.75

0.25

0.5

5.0

2.5

2.0

6.75

2.25

8070

60

50

40

3027

20

10 9 8 7

6

5

4

3

2

1 10

3 2

50

Pressure in Pa

m /

h/m

of

ove

rall

area

3 m /

h/m

of o

peni

ng li

ght

100 150 300 600

2

3

4

1

C

A B

Key

1 Class 1

2 Class 2

3 Class 3

4 Class 4

Maximum test levels are: Class 1 = 150 Pa; Class 2 = 300 Pa; Classes 3 and 4 = 600 Pa.

NOTE 1 The classification graph has been generated from the equation and details in BS EN 12207:2000,Clause 4.NOTE 2 Broken lines on graph denoted A, B and C illustrate approximate requirements of BS 6375-1:2009.


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8 Test for resistance to wind

8.1 The specimen shall be tested in accordance with BS EN 12211 andclassified in accordance with BS EN 12210. Classification levelsapplicable in the UK shall be in accordance with Table 1. Wind loadingshall be calculated in accordance with Annex A.

NOTE 1 For the purpose of the tests, three sets of test pressure aredefined:

* P1 applied to measure the deflection of parts of the testspecimen;

* P2 pulsating pressure applied for 50 cycles to assess performanceunder repeated wind loads;

* P3 applied to assess the safety of the specimen under extremeconditions.

The values of P1, P2 and P3 are related as follows: P2 = 0.5 P1, andP3 = 1.5 P1.

NOTE 2 BS EN 1026, which is cited within BS EN 12211, gives the negativepressure test as an option. However, BS 6375 follows the convention ofBS EN 14351-1, which requires both positive and negative pressure testingto be undertaken and the results averaged.

NOTE 3 The resistance to wind load test, BS EN 12211, specifies a repeatair permeability test. This repeat air test is conducted with both positiveand negative pressures. The assessment of the increase in air permeabilityis based on the numerical average of the positive and negative airpermeability values (m3/h) at each pressure step.

8.2 The deflection of any deforming framing member shall be limitedto 1/150 of its length (Class A for relative frontal deflection) whensubjected to the wind load of P1.

8.3 If glass breakage occurs without damage to the frame members,the unit shall if necessary be reglazed once and re-tested.


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Annex A (normative) Calculating wind load and selectingexposure category

A.1 General

Either the method specified in A.2 or the method specified inBS 6399-2 shall be used for determining the design wind loading fornon low-rise buildings.

NOTE 1 For the purpose of classification to this British Standard, thereare two acceptable methods of determining the design wind loading forlow-rise buildings. The method specified in A.2 is abbreviated; the onespecified in BS 6399-2 is more detailed and less conservative.

NOTE 2 The designer or specifier should take into account any otherforms of loading to which the window or doorset might be subjected.

The exposure category shall be selected in accordance with A.3.

A.2 Abbreviated method of determination of wind loadfor low-rise buildings

A.2.1 Procedure

To find the wind load the procedure below shall be followed.

a) Using the site location, select the basic wind speed Vb fromFigure A.1.

b) Select the site terrain category (A, B, C, D, E or F) in accordancewith A.2.2.

c) Determine the design height (H) [see Note a) and b)] for the wallor walls in which the windows or doorsets are to be installed orthe ridge height for dormer windows, and select the designheight band to be used.

d) Using the basic wind speed Vb, the site terrain category and thedesign height (H), select the wind load at sea level in accordancewith A.2.3.

e) Determine the altitude factor (FA) in accordance with A.2.4.

f) Determine the appropriate topographical factor (FT) inaccordance with A.2.5.

g) Determine the dormer factor (FD) (see A.2.6).

h) Determine the funnelling factor (FF) (see A.2.7).

i) The wind load is given by equation A.1:

Table A.3 value � FA � FT � FD � FF (A.1)

where:

FA is the altitude factor;

FT is the topographical factor;

FD is the dormer factor;

FF is the funnelling factor.


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Figure A.1 Basic wind speed map Vb (from BS 6399-2)

0

0 20 40 60 80 100

40 80 120 160Kilometres

Statute miles

Channel islands 24 m/s

Belfast

Londonderry

Inverness

Aberdeen

Dundee

PerthOban

Glasgow Edinburgh

Newcastle

Carlisle

YorkLeedsPreston

Stoke

Manchester

Sheffield

Nottingham

Leicester

BirminghamNorwich

IpswichBedford

BristolCardiff

Swansea

LONDON

Oxford

BrightonBournemouth

Plymouth

NorthamptonAberystwyth

Liverpool

Kingstonupon-Hull

National grid

0 0

1

2

3

4

0

1

2

3

4

5

6

7

8

99

10

7

8

10

11

12

1 2 3 4 5 6 7

1

0 1 2 3

01

23

4

5 6 7

Irish grid

31

30

2928

27

26

26

25

25

25

24

24

24

24

25

23

23

23

23

22

21

20

25

24

23


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NOTE Although the wind load determined according to A.2.1 might notbe identical to a loading derived from BS 6399-2, it is sufficiently accurateto be used for most low-rise buildings. The limitations in this abbreviatedmethod are:

a) the overall design height (H) is limited to a maximum of 15 m;

b) the method assumes a combined pressure coefficient (CP) of 1.15,which takes into account the worst case that normally occurs.Higher coefficients might be experienced at points adjacent to thecorners of the building.

An alternative is to use an appropriate figure provided by the buildingdesigner. If a design wind loading figure is not available from thedesigner, an appropriate figure can be determined by the methoddescribed in BS 6399-2. If the complexities are beyond the scope ofthat standard, further advice should be sought.

A.2.2 Site terrain categories

NOTE See Table C.1 forderivation of Sb factors for eachdesign height.

Site terrain categories shall be selected from Table A.1.

Table A.1 Site terrain categories

Description Category

Open country up to 10 km from open sea A

Open country more than 10 km and up to 50 km fromopen sea

B

Open country more than 50 km from open sea C

Town areas up to 10 km from open sea D

Town areas more than 10 km and up to 50 km fromopen sea

E

Town areas more than 50 km from open sea F

A.2.3 Wind load at sea level (0 m altitude)

NOTE Annex C explains how thewind loads in Table A.2 werederived.

Wind load at sea level shall be determined using Table A.2.


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Table A.2 Wind load at sea level

Site wind speed (Vs)at sea level

Design height (H) Wind load at sea level for site terrain category (see Table A.1)

A B C D E Fm/s m Pa Pa Pa Pa Pa Pa

20 43 1 669 1 569 1 537 1 469 1 441 1 413>3 and 46 1 796 1 722 1 677 1 677 1 634 1 601>6 and 410 1 893 1 844 1 786 1 844 1 805 1 758>10 and 415 1 965 1 934 1 873 1 965 1 934 1 883

21 43 1 737 1 627 1 592 1 517 1 486 1 455>3 and 46 1 877 1 796 1 747 1 747 1 699 1 663>6 and 410 1 985 1 930 1 867 1 930 1 888 1 836>10 and 415 1 064 1 030 1 963 1 064 1 030 1 974

22 43 1 809 1 688 1 650 1 568 1 533 1 500>3 and 46 1 963 1 873 1 820 1 820 1 768 1 727>6 and 410 1 081 1 021 1 952 1 021 1 974 1 918>10 and 415 1 168 1 130 1 057 1 168 1 130 1 069

23 43 1 884 1 752 1 710 1 621 1 583 1 546>3 and 46 1 053 1 955 1 896 1 896 1 839 1 795>6 and 410 1 182 1 116 1 040 1 116 1 065 1 003>10 and 415 1 276 1 235 1 155 1 276 1 235 1 168

24 43 1 963 1 819 1 773 1 676 1 634 1 594>3 and 46 1 146 1 039 1 976 1 976 1 914 1 866>6 and 410 1 287 1 215 1 132 1 215 1 160 1 092>10 and 415 1 390 1 345 1 258 1 390 1 345 1 272

25 43 1 045 1 888 1 839 1 733 1 688 1 645>3 and 46 1 244 1 128 1 059 1 059 1 991 1 939>6 and 410 1 396 1 319 1 229 1 319 1 258 1 185>10 and 415 1 508 1 459 1 365 1 508 1 459 1 380

26 43 1 130 1 961 1 908 1 793 1 745 1 698>3 and 46 1 345 1 220 1 145 1 145 1 072 1 016>6 and 410 1 510 1 426 1 329 1 426 1 361 1 282>10 and 415 1 631 1 579 1 476 1 631 1 579 1 493

27 43 1 219 1 036 1 979 1 855 1 803 1 752>3 and 46 1 450 1 316 1 235 1 235 1 156 1 095>6 and 410 1 628 1 538 1 433 1 538 1 468 1 382>10 and 415 1 759 1 702 1 592 1 759 1 702 1 610

28 43 1 311 1 114 1 053 1 920 1 864 1 809>3 and 46 1 560 1 415 1 328 1 328 1 244 1 178>6 and 410 1 751 1 654 1 541 1 654 1 579 1 486>10 and 415 1 892 1 831 1 712 1 892 1 831 1 731

29 43 1 406 1 195 1 129 1 987 1 926 1 868>3 and 46 1 673 1 518 1 424 1 424 1 334 1 264>6 and 410 1 878 1 774 1 653 1 774 1 693 1 595>10 and 415 2 029 1 964 1 836 2 029 1 964 1 857

30 43 1 505 1 279 1 208 1 056 1 991 1 929>3 and 46 1 791 1 624 1 524 1 524 1 428 1 352>6 and 410 2 010 1 899 1 769 1 899 1 812 1 706>10 and 415 2 171 2 102 1 965 2 171 2 102 1 988

31 43 1 607 1 366 1 290 1 127 1 059 1 992>3 and 46 1 912 1 734 1 628 1 628 1 524 1 444>6 and 410 2 146 2 028 1 889 2 028 1 935 1 822>10 and 415 2 319 2 244 2 098 2 319 2 244 2 122

NOTE 1 The values are rounded.

NOTE 2 Pa = N/m2.


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A.2.4 Altitude factor

Altitude factor (FA) shall be selected from Table A.3 or determinedfrom equation A.2.

Table A.3 Table for factor FA for specific altitudes

Altitudem

Factor FA Altitudem

Factor FA

0 1.00 225 1.56

25 1.05 250 1.56

50 1.10 275 1.63

75 1.16 300 1.69

100 1.21 325 1.76

125 1.27 350 1.82

150 1.32 375 1.89

175 1.38 400 1.96

200 1.44 425 2.03

(A.2)

where:

HA is the altitude of the site, in metres (m).

A.2.5 Topographical factors

Topographical factors shall be used where hills, ridges, cliffs andescarpments might have an adverse effect on the wind load of abuilding. The appropriate topographical factor shall be obtainedusing Table A.4.

Table A.4 Topographical factor

Topographical category and description Factor FT according to zone from Figure A.2

Zone 1 Zone 2 Zone 3 Elsewhere

Category 1: Nominally flat terrain ground slope <1/20 1.0 1.0 1.0 1.0

Category 2: Moderately steep terrain ground slope 41/5 1.54 1.28 1.21 1.0

Category 3: Steep terrain ground slope >1/5 1.85 1.44 1.32 1.0


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Figure A.2 Topographic zones

Zone 2 Zone 2Zone 1

0.4Lu 0.4Lu 0.4Ld 0.4Ld

Lu Ld

Zone 2 Zone 2 Zone 3Zone 1

0.25Lu 0.4Lu0.25Lu 0.4Lu 1.2Lu

Lu

Key

Ld Length of downwind slope of topographic feature

Lu Length of upwind slope of topographic feature

A.2.6 Dormer factor

To allow for the fact that any form of vertical roof glazing, such asdormer windows, might be subject to higher loads than those on avertical face, the wind load shall be multiplied by a dormer factorof 1.6 for windows in these locations. For all other situations a dormerfactor of 1.0 shall be used.

A.2.7 Funnelling factor

In site terrain categories A, B, C and D where walls of two building faceeach other, and the gap between them is less than their cross-windwidth, the design wind load for doorsets and windows in the facingwalls shall be multiplied by a funnelling factor of 1.3.

For other site terrain categories and buildings not subject to thefunnelling effect, a funnelling factor of 1.0 shall be used.

A.3 Selection of the exposure category

Using the wind load determined in equation A.1, select the nexthighest P1 value in Table 1. Where more than one exposure categoryis available at a given P1 value, the water tightness and airpermeability shall be taken as the worst case scenario.


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Annex B (informative) Flow chart of sequence of testThe sequence of tests specified in Clause 5 is illustrated in Figure B.1.

Figure B.1 Flow chart of sequence of test

BS 6375-1:2009

Air permeability

BS EN 1026

Air permeabilityPositive air pressure

Air permeabilityNegative air pressure

Correct for temp andatmos pressure

Average +ve and -veresults at each pressure

step

BS EN 12207

Classify using Fig 1

Watertightness

BS EN 1027

Watertightness test

BS EN 12208

Classify using Table 1

Resistance to wind

BS EN 12211

Positive wind pressuretest to P1

Negative wind pressuretest to P1

Repeated pressure test+P2 to -P2

Air permeabilityPositive air pressure

Air permeabilityNegative air pressure

Correct for temp andatmos pressure

Average +ve and -veresults at each pressure

stepCompare with original

test (Clause 6)

Wind loading safetypressure test

BS EN 12210

Classify using Table 1


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Annex C (informative) Derivation of the wind load in Table A.2The values of wind load have been derived from BS 6399-2 using thefollowing parameters.

The basic wind speed, Vb, has been derived from site location usingFigure A.1.

The site wind speed, Vs, has been calculated using equation C.1:

Vs = Vb 6 Sa 6 Sd 6 Ss 6 Sp (C.1)

where:

Vb is the basic wind speed, in metres per second (m/s);

Sa is the altitude factor;

Sd is the direction factor;

Ss is the seasonal factor;

Sp is the probability factor.

In this abbreviated method, factors Sa, Sd, Ss and Sp all have a valueof 1.0.

Therefore in the abbreviated method, Vs = Vb.

NOTE 1 Design heights, H, up to 3 m, up to 6 m, up to 10 m and upto 15 m high have been considered in Table A.3.

NOTE 2 For simplicity the effective height, He, has been taken as thedesign height (H).

The effective wind speed, Ve, has been calculated using equation C.2:

Ve = Vs 6 Sb (C.2)

where:

Vs is the site wind speed, in metres per second (m/s);

Sb is the terrain and building factor.

From BS 6399-2:1997, Table 4, for components of dimension 5 m orless, the terrain and building factors, Sb, given in Table C.1 have beencalculated.

Table C.1 Terrain and building factor Sb

Design height (H)m

Factor Sb according to site terrain category (see Table A.1)

A B C D E F

43 1.54 1.42 1.38 1.29 1.25 1.21

>3 and 46 1.68 1.6 1.55 1.55 1.5 1.46

>6 and 410 1.78 1.73 1.67 1.73 1.69 1.64

>10 and 415 1.85 1.82 1.76 1.85 1.82 1.77

The reference pressure, qs, has been calculated using equation C.3:

(C.3)

where:

Ve is the effective wind speed, in metres per second (m/s).

The combined pressure coefficient, CP, is 1.15.


14 . BSI 2008

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Thus the wind load, P, has been calculated using equation C.4:

(C.4)

where:

qs is the reference pressure, in pascals (Pa);

CP is the combined pressure coefficient.

If building heights or combined pressure coefficients are differentfrom those assumed, an actual wind load, P, can be calculated andused in step A.2.1d).


BSI 2008 . 15

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Bibliography

For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (includingany amendments) applies.

BS 5516 (both parts), Patent glazing and sloping glazing for buildings

BS 6375-2, Performance of windows and doors – Part 2: Classificationfor operation and strength characteristics and guidance on selectionand specification

BS 6375-3, Performance of windows and doors – Part 3: Classificationfor additional performance characteristics and guidance on selectionand specification

PAS 23-1, General performance requirements for door assemblies –Part 1: Single leaf, external door assemblies to dwellings


16 . BSI 2008

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Documents

BS-6375-1-2009-Performance-of-windows-and-doors-–-Part-1-Classification-for-weathertightness-and-guidance-on-selection-and-specification