1、BRITISH STANDARD BS 5241-1: 1994 Rigid polyurethane (PUR) and polyisocyanurate (PIR) foam when dispensed or sprayed on a construction site Part 1: Specification for sprayed foam thermal insulation applied externallyBS5241-1:1994 This British Standard, having been prepared under the directionof the P
2、lastics and Rubber Standards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 15 March1994 BSI 07-1999 First published June 1989 Second edition March 1994 The following BSI references relate to the work on this standard: Committee reference PRM/72 Dra
3、ft for comment 92/46319 DC ISBN 0 580 22807 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Plastics and Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/72, upon which the following bodies were represented: Associa
4、tion of Building Component Manufacturers Brick Development Association British Board of Agrement British Plastics Federation British Rigid Urethane Foam Manufacturers Association Calcium Silicate Brick Association Limited Cavity Foam Bureau Department of the Environment (Building Research Establishm
5、ent) Department of the Environment (Construction Directorate) Engineering Equipment and Materials Users Association European Phenolic Foam Association Flat Roofing Contractors Advisory Board Ministry of Defence National Federation of Roofing Contractors National House-building Council Polyethylene F
6、oam Insulation Association Royal Institute of British Architects The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Ceramic Research Ltd. British Urethane Foam Contractors Association (BUFCA) Department of the Environment RAPRA Techn
7、ology Ltd. Amendments issued since publication Amd. No. Date CommentsBS5241-1:1994 BSI 07-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Designation 1 4 Composition 1 5 Test specimens and sampling 1 6 Physical properties 2 7 Marking 2 Annex A (i
8、nformative) Notes for designers 3 Annex B (normative) Method for determination of apparent water absorption 3 Annex C (informative) Burning properties of rigid polyurethane and polyisocyanurate foam and recommendations regarding their use 4 Table 1 Designation codes for thermal conductivity 1 Table
9、2 Physical properties 2 List of references Inside back coverBS5241-1:1994 ii BSI 07-1999 Foreword This Part of BS5241 has been prepared under the direction of the Plastics and Rubber Standards Policy Committee. It is revision of BS5241-1:1989 which is withdrawn. The1989revision of BS5241:1975 result
10、ed in the separation of the standard into two Parts to reflect trends in current technology. In BS5241-1:1989 the specific requirements of sprayed PUR and PIR foams applied externally were detailed, whereas Part2covered the requirements for applications where the foam is dispensed. Also in BS5241-1:
11、1989 the advice to users was updated, a water absorption method added and the physical property requirements amended to take account of the revised test methods described in the latest revision of BS4370. This edition introduces technical changes but it does not reflect a full review or revision of
12、the standard. A requirement has been included for the thermal conductivity of the foam to be designated by the manufacturer. It is envisaged that this standard will be replaced by a European Standard in due course and that the European Standard will be adopted in the BSEN series. Attention is drawn
13、to BS7021, a code of practice for the thermal insulation of roofs externally by means of sprayed polyurethane (PUR) or polyisocyanurate (PIR) foam, which is published simultaneously. WARNING. Adequate fire precautions should be taken when repairing any structure containing PUR or PIR foams. Do not u
14、se welding or flame cutting equipment. The attention of contractors and purchasers is drawn to the fact that this specification covers the foam only. In almost all cases, sprayed foam requires some surface treatment or covering in order to conform to the surface spread of flame rating appropriate to
15、 the final application (seeAnnex C and BS7021), to provide protection from ultraviolet light and to confer weatherproofing. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance
16、with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had a
17、mendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5241-1:1994 BSI 07-1999 1 1 Scope This Part of BS5241 specifies the physical property and compositional requirements for externally sprayed polyurethane (PUR) and polyisocyanurate (PIR) foams used for t
18、he thermal insulation of external surfaces, e.g.roofs and storage tanks. 2 References 2.1 Normative references This Part of BS5241 incorporates, by reference, provisions from specific editions of other publications. These normative references are cited at the appropriate points in the text and the p
19、ublications are listed on the inside back cover. Subsequent amendments to, or revisions of, any of these publications apply to this Part of BS5241 only when incorporated in it by updating or revision. 2.2 Informative references This Part of BS5241 refers to other publications that provide informatio
20、n or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest editions. 3 Designation For the purposes of this British Standard, the materials are divided into four types, as follows: Types1
21、and2differ principally from types3and4in their burning characteristics. Types2and4are specified where greater robustness is required e.g.in the insulation of roofs externally, where the slope of the roof is less than45 (see3.2 of BS7021:1989). The designation shall consist of a three component code
22、comprising the following items, in the order presented: a) the number and date of this British Standard i.e.BS5241-1:1994; b) a number indicating the foam type; c) a double digit number to indicate the thermal conductivity selected in accordance withTable 1. An example of the designation required fo
23、r a type4foam with a thermal conductivity of0.02W/(mK) is as follows: BS 5241-1:1994/4/20. Table 1 Designation codes for thermal conductivity 4 Composition The material shall be of rigid polyurethane (PUR) or polyisocyanurate (PIR) foam. A material indicated by (PUR) shall be substantially composed
24、of urethane linkages and one indicated by (PIR) shall be substantially composed of isocyanurate linkages. NOTENo requirement for odour is included as its assessment is largely subjective. However, it is recommended that the material should be free from objectionable odour. 5 Test specimens and sampl
25、ing Test specimens shall be prepared from samples trepanned from the foam during installation or, if trepanning is impracticable, special test samples shall be prepared by a suitable method. Suitable precautions shall be taken to ensure that the spaces left by extracting the samples are infilled wit
26、hout delay. Type 1 polyurethane foams suitable for general use; Type 2 polyurethane foams suitable for use where there is a requirement for greater resistance to compressive forces; Type 3 polyisocyanurate foams suitable for general use; Type 4 polyisocyanurate foams suitable for use where there is
27、a requirement for greater resistance to compressive forces. Thermal conductivity (see6.1) W/(mK) Code 0.015 0.016 0.017 0.018 0.019 0.020 0.021 0.022 0.023 0.024 0.025 0.026 0.027 0.028 0.029 0.030 0.031 0.032 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 NOTEThese values are30day values for
28、 quality control purposes. For corresponding long-term design values the manufacturers advice should be sought (seeAnnex A).BS5241-1:1994 2 BSI 07-1999 6 Physical properties 6.1 Thermal conductivity Thermal conductivity shall be determined by either method7A or7B of BS4370-2:1993 at a mean temperatu
29、re of10 C (30 2) days after manufacture. Materials shall be conditioned throughout this period at (23 2) C and (50 5)% r.h. NOTESee additional guidance in Annex A concerning the thermal conductivity3day values and design values. 6.2 Other properties The materials shall conform to the requirements gi
30、ven in Table 2 when tested in accordance with the appropriate methods listed. 7 Marking The containers or invoice shall be marked with at least the following information: a) manufacturers name or trademark; b) product designation as given in clause3 1) ; c) manufacturers description and/or product r
31、eference. Table 2 Physical properties 1) Marking BS 5241-1:1994 on or in relation to a product represents a manufacturers declaration of conformity, i.e.a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the claim is solely the claima
32、nts responsibility. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable. Physical property Test requirement Test method Type 1 Type 2 Type 3 Type 4 Minimum compressive strength (in kPa) (seeAnnex A) 175 250 175 250 Method 3 of BS 4370-1:
33、1988 applying the force in a direction normal to the major plane of the foam Dimensional stability: maximum change (in %) Method 5A or 5B of BS 4370-1:1988 Test conditions: 24 h at 15 2 C 1 1 1 1 24 h at 100 2 C 2 2 2 2 24 h at 125 2 C 2 2 24 h at 70 2 C 3 3 3 3 and 95 5 % r.h. Closed cell content:
34、minimum apparent volume (in %) 85 85 85 85 Method 10 of BS 4370-2:1993 Burning characteristics: BS 4735:1974 (see note) extent of burning (in mm) 125 125 25 25 Maximum water vapour permeability at38 C and88% r.h. (in ng/Pasm) 5.5 5.5 8.5 8.5 Method 8 of BS 4370-2:1993 condition a) Maximum apparent w
35、ater absorption by volume (in %) 6.5 6.5 6.5 6.5 Annex B NOTEThe small scale laboratory test described in BS4735 is solely for assistance in monitoring consistency of production and isnot for use as a means of assessing potential fire hazard of a material in use (seeAnnex C).BS5241-1:1994 BSI 07-199
36、9 3 Annex A (informative) Notes for designers Attention is drawn to the following points of specific relevance to rigid PUR and PIR foams. a) Materials of minimum overall density35kg/m 3are usually found to be suitable for roofs with slopes greater than or equal to45 and storage tank sides (type1and
37、 type3). Those of minimum overall density48kg/m 3are usually suitable for applications in which there is a requirement for a greater robustness (type2and type4), such as roofs, including flat roofs, with slopes of less than45 and storage tank tops. b) In addition to the30day maximum thermal conducti
38、vity value which forms the specification value for the purposes of this standard, two related maximum thermal conductivity values have practical importance, and should be obtained for the product from the manufacturer as follows. 1) Design value of thermal conductivity. This figure takes into accoun
39、t the limited diffusion of gases which can be used as a basis for user calculations. Generally this will be higher than or equal to the30day value. 2) The3day value of thermal conductivity. This value is often used in manufacturing control operations, to ensure the quality of product is regularly ma
40、intained. Generally it will be lower than or equal to the30day value. c) It has been established that a negligible increase in thermal conductivity occurs within the density range of28kg/m 3to71kg/m 3 . d) When the foam is applied externally it is essential that it is adequately protected. It is ess
41、ential that reference is made to BS7021:1989 for guidance on the insulation of roofs externally by means of sprayed rigid polyurethane (PUR) or polyisocyanurate (PIR) foam. Annex B (normative) Method for determination of apparent water absorption B.1 Principle This method describes a procedure for d
42、etermining the apparent water absorption of rigid cellular materials resulting from immersion in water under special conditions of depth and time. The principle of the method is that the buoyant force of an object less dense than water when submerged is equal to the weight of water it displaces less
43、 the dry weight of the object. Water absorbed by the object reduces the buoyant force by reducing the volume of water replaced. The water absorption may be determined by measuring the change of buoyant force. The method described is intended for quality control purposes and does not include correcti
44、ons for the volume of water in the cut surface cells of the test specimen. B.2 Apparatus and materials B.2.1 A balance, capable of measurement to an accuracy of0.01g with provision for making submerged weighings. B.2.2 An underwater weighing jig, constructed from a material not attacked by distilled
45、 water and large enough to contain one test specimen. A sinker is attached to the base of the jig, so that the combined weight of sinker and jig is sufficient to overcome the upthrust of the test specimen. The jig is also fitted with a means of suspending it from the balance and is constructed so th
46、at it traps no air when submerged. B.2.3 A mesh cage, constructed from a material not attacked by distilled water and large enough to contain a minimum of three test specimens. The cage is weighted sufficiently to overcome the upthrust of the test specimens. B.2.4 An immersion tank, capable of accom
47、modating the mesh cage and underwater weighing jig and at least150mm in depth. B.2.5 De-aerated distilled water B.2.6 Low permeability plastics film B.3 Test specimen The test specimen shall be a rectangular block with length, width and thickness each (50 1)mm. The test specimen shall be free from v
48、oids and blemishes, shall have the surface skin removed and shall be prepared with minimal deformation of the original cellular structure in such a way that only the surface layer of cells is opened. NOTERough cutting on a band saw followed by trimming on a suitable slicing machine has been found sa
49、tisfactory for the preparation of test specimens. Hot wire cutting should not be used.BS5241-1:1994 4 BSI 07-1999 B.4 Conditioning The test specimens shall be conditioned for not less than16h at (23 2) C and (50 5)% r.h. before testing. The test shall be conducted at (23 2) C. B.5 Procedure Test a minimum of three test specimens. Determine the mean length, width and thickness of each test specimen as described in method1of BS4370-1:1988 taking readings along the centre of each face. If the individual readings of length
