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In accordance with the requirements of Notice on publishing the development and revision plan on Guangdong provincial engineering construction standards in 2017 issued by Guangdong Provincial Department of Housing and Urban-Rural Development (YUEJIANKEHAN [2017] No. 2904), the drafting group of Technical specifications for metal roofing system in areas prone to strong winds has formulated the specifications through extensive investigation and study, careful summarization of practical experience and reference to relevant international and foreign advanced standards and on the basis of widely soliciting for opinions.
The main technical contents of the specifications are: general provisions, terms and symbols, basic requirements, metal roofing materials, construction design, structural design, fabrication, transportation and storage, installation, quality acceptance, maintenance and repair, and metal roofing performance testing.
Guangdong Provincial Housing and Urban-Rural Construction Department is in charge of the administration of the specifications, and South China University of Technology and Guangdong Baianli Light Steel Structure Products Co., Ltd. are responsible for the explanation of specific technical contents. In case of any comment or suggestion in the process of implementing the specifications, please send it to the management group of Technical specifications for metal roofing system in areas prone to strong winds of South China University of Technology (Address: School of Civil Engineering and Transportation, South China University of Technology, No. 381 Wushan Road, Tianhe District, Guangzhou; 510641).
Contents
Foreword i
1 General provisions 1
2 Terms and symbols 1
2.1 Terms 1
2.2 Symbols 2
3 Basic requirements 3
4 Metal roofing materials 4
4.1 General requirements 5
4.2 Purlin 5
4.3 Substructure components 5
4.4 Fixing clips 5
4.5 Fasteners 5
4.6 Profiled metal sheet 6
4.7 Vapor barrier and breather membranes 8
4.8 Thermal insulation materials 8
4.9 Sealing materials 8
4.10 Miscellaneous materials 9
5 Construction design 9
5.1 General requirements 9
5.2 Waterproof and drainage design 10
5.3 Thermal insulation and moisture-proof design 12
5.4 Fire protection design 13
5.5 Lightning protection design 13
5.6 Sound insulation and noise reduction design 14
5.7 Weather resistance design 15
5.8 Temperature deformation design 15
5.9 Design of attached facilities 16
5.10 Detailed structural design 17
6 Structural design 19
6.1 General requirements 19
6.2 Load action and effect 19
6.3 Profiled metal sheet 22
6.4 Construction requirements 23
7 Fabrication, transportation and storage 23
7.1 General requirements 23
7.2 Fabrication requirements 24
7.3 Permissible deviation 24
7.4 Transportation 26
7.5 Storage 26
8 Installation 27
8.1 General requirements 27
8.2 Installation of substructure components and fixing chips 28
8.3 Laying of sound insulation and sound absorption layer, vapor barrier, breather membrane and thermal insulation layer 30
8.4 Installation of profiled metal sheet 31
8.5 Installation of other components 32
9 Quality acceptance 34
9.1 General requirements 34
9.2 Quality control and inspection batch division requirements 34
9.3 Safety and function requirements 35
10 Maintenance and repair 36
10.1 General requirements 36
10.2 Maintenance and repair 36
11 Metal roofing performance testing 38
11.1 General requirements 38
11.2 Testing regulations 39
Annex A Metal roofing performance testing method 42
A.1 Weather resistance testing method 42
A.2 Test method for wind driven rain penetration on metal roofing 43
A.3 External fire protection testing method of metal roofing 45
A.4 Test method for metal roofing displacement 47
A.5 Fatigue resistance test of external attachment of metal roofing 48
A.6 Wind resistance testing method for metal roofing 50
A.7 Classification and testing method of impact performance of metal roofing against wind-borne debris 53
A.8 Treading test procedure and method 55
A.9 Method for wind resistance detection of metal roofing prominent members 56
A.10 Fatigue resistance test of connecting members 57
Annex B Chemical composition and mechanical properties of steel, aluminum alloy and stainless steel 59
Annex C Performance requirements for thermal insulation materials of metal roofing 66
Annex D Distribution map of wind pressure in strong wind area 68
D.1 Distribution map of wind pressure in strong wind area in China 68
D.2 Distribution map of wind pressure in strong wind area in the province 68
Annex E Schematic diagram for wind sensitive zone and connection details 70
Annex F Acceptance requirements for inspection quality of raw materials and components 74
F.1 Site acceptance of raw materials and products 74
F.2 Manufacture quality acceptance 79
F.3 Installation quality acceptance 80
Explanation of wording in the specifications 87
List of quoted codes 88
Technical specifications for metal roofing system in areas prone to strong winds
1 General provisions
1.0.1 The specifications is formulated to make the design, manufacturing and installation of metal roofing in areas prone to strong winds and with the basic wind pressure of not less than 0.5KN/m2 conform to the national technical and economic policies and green evaluation standards, so as to achieve advanced technology, safety and durability, reduce wind damage and ensure quality and economic rationality.
1.0.2 The specifications is applicable to the design, manufacturing, installation, acceptance, testing, maintenance and repair of metal roofing of constructed, extended and renovated industrial and civil buildings in areas prone to strong winds.
1.0.3 In addition to the specifications, the design, manufacturing, installation, acceptance, testing, maintenance and repair of metal roofing shall also meet the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1 metal roofing
building roofing system that is mainly made of profiled metal sheet and connected to the main structure via fasteners (such as screws), components and secondary structures, and combines the built-up functional structural layers of heat insulating, waterproof, moisture-proof, vapor-proof, sound-absorbing and sound-insulating materials, so as to meet the functional requirements of the building, and transfer the loads and actions to the building roofing system of the main structure; it includes single-skin metal roofing and built-up metal roofing
2.1.2 single-skin metal roofing
roofing system formed by directly fixing the single-skin profiled metal roofing panel system on secondary structure only considering the functions of shading, rain protection and waterproofing, without the structural layer of thermal insulation and other functions
2.1.3 built-up metal roofing
roofing system which connects prefabricated components with multiple functions such as bottom plate, heat insulating material, internal support, membrane and metal roofing panel together by fasteners
2.1.4 profiled metal sheet
finished metal sheet with continuous waveform or other sections along the sheet width direction through rolling and cold bending
2.1.5 component
single component bearing various actions in the metal roofing, or a component of a system
2.1.6 fastener
part used for structural connection between metal sheets and between metal sheet and flashing plate
2.1.7 attached facilities
mainly referring to the wind-resistant fixtures, maintenance and overhaul passages, ladders, snow protection facilities, lightning protection facilities, photovoltaic systems, decoration systems, etc. of building metal roofing
2.1.8 strong wind area
area where the basic wind pressure at a recurrence interval of 50 years is not less than 0.5kN/m2 and other areas prone to typhoons
2.1.9 high wind pressure zone
high wind pressure zone on roofing refers to the area with large positive and negative wind pressure locally due to potential strong air flow and separation under the action of wind, such as the edges and corners of the roofing
2.1.10 wind sensitive zone
wind sensitive zone on roofing refers to the corner part of high wind pressure zone, which shall be determined by wind tunnel test
2.1.11 sealing waterline
position preventing water from invading the building by connecting the profiled metal sheets through engagement and locking
2.1.12 product testing of metal roof system
overall quality determination assurance and method of the metal roofing system manufacturer on the produced system, including side flashing; generally, the system performance index shall be obtained after a series of testings by calculation and testing organizations; the manufacturer of metal roofing system shall take quality control measures to ensure that the system quality meets the system performance index of product testing
2.2 Symbols
2.2.1 Wind load
wk——the standard value of wind load, kN/m2;
w″k——the standard value of wind load in high wind pressure zone, kN/m2;
w′k——the standard value of wind load in wind sensitive zone, kN/m2;
wd——the design value of wind load, kN/m2;
w0——the basic wind pressure, kN/m2;
yh——the wind pressure adjustment coefficient in local high wind pressure zone on roofing;
ys——the wind pressure adjustment coefficient in local wind sensitive zone on roofing;
βgz——the gustiness coefficient at the height of z;
μsl——the local shape coefficient of wind load;
μz——the height variation coefficient of wind pressure;
2.2.2 Temperature displacement
L——the design length of profiled metal sheet, m;
α——the linear expansion coefficient of metal, l/℃;
△L——the length deformation of profiled metal sheet, mm;
△T——the temperature variation of profiled metal sheet, ℃.
3 Basic requirements
3.0.1 The metal roofing shall be free of damage or leakage under the action of strong wind and rainstorm.
3.0.2 The metal roofing shall have good drainage function and be able to prevent water from leaking into buildings.
3.0.3 The metal roofing shall have good weather resistance and be able to prevent fire from spreading.
3.0.4 The metal roofing shall meet the aesthetic appearance and use requirements of buildings.
3.0.5 When the metal roofing is made of different metal materials, insulating gaskets or other anti-corrosion measures shall be provided. Rubber insulation pad should be arranged at the lower part of the fixed bracket of profiled metal sheet.
3.0.6 The construction design shall be based on local climatic conditions, architectural grade, use function, architectural modeling, energy saving, construction technology, etc.
3.0.7 The metal roofing shall be subjected to special detailed design, and the detailed design documents shall be confirmed by the original designer and conform to the current relevant national standards.
3.0.8 The metal roofing supplier shall carry out the product testing of metal roof system and carry out test according to the method in Annex A hereof. The testing items shall be all of those specified in Table 11.2.3, and the testing results shall include the design requirements of all projects participated before the next step of detailed design. Among product testing items, the testing on wind resistance shall be carried out on the same structure for three or more times, and the design selection interval of performance index shall be formed.
3.0.9 The design service life of metal roofing shall meet those specified in Table 3.0.9.
Table 3.0.9 Design service life of metal roofing
Category Design service life Description
1 5 years Temporary buildings
2 25 years Easily replaceable buildings
3 50 years General buildings
4 100 years Monumental buildings and very important buildings
3.0.10 The metal roofing shall be subjected to performance inspection according to design requirements and shall meet the requirements of Annex A.
3.0.11 The bearing capacity of the substructure shall be determined through calculation or test.
3.0.12 The metal roofing should be fixed by bolts, self-tapping self-drilling screws and blind rivets. For fixing by fasteners, the structural performance, applicable scope, thread spacing, material, color, durability and weather resistance of gaskets shall be considered.
4 Metal roofing materials
4.1 General requirements
4.1.1 The durability of metal roofing materials shall meet the requirements of design service life.
4.1.2 The metal roofing materials shall be incombustible or nonflammable, and shall meet the requirements of current relevant national standards.
4.1.3 The raw materials of profiled metal sheet shall comply with the relevant standards and the requirements of the order contract, and the raw material manufacturer shall issue the product quality certificate.
4.2 Purlin
4.2.1 Low alloy high strength steel sheet should be used as purlin material.
4.3 Substructure components
4.3.1 The minimum nominal thickness of sheets used for substructure components shall not be less than 0.75mm.
4.3.2 When coated steel sheets are used for substructure components, the weight of surface galvanized layer (on both sides) shall not be less than 275g/m2, and the weight of surface aluminized layer (on both sides) shall not be less than 185g/m2.
4.4 Fixing clips
4.4.1 The fixing clips of profiled metal sheet should be made of materials the same as or compatible with the roofing panel material.
4.4.2 When carbon steel material is adopted for the fixing clip, the surface shall be coated, and the weight of surface galvanized layer (on both sides) shall not be less than 275g/m2, and the weight of surface aluminized layer (on both sides) shall not be less than 185g/m2.
4.4.3 When aluminum alloy fixing clip is adopted, the material should be 6061 aluminum alloy, the thickness at the thinnest part shall not be less than 3mm, and the surface treatment requirements shall meet the current standards of the nation.
4.4.4 When stainless steel clip is adopted, the thickness of sheet shall not be less than 0.5mm.
4.5 Fasteners
4.5.1 The stainless steel fasteners for metal roofing should be made of 300 series and 400 series stainless steel.
4.5.2 The bolts for purlin connection may be made of carbon steel or stainless steel, and shall comply with the current national standard GB/T 3098 Mechanical properties of fasteners.
4.6 Profiled metal sheet
4.6.1 The profiled metal sheet shall meet the following requirements:
1 the Al-Zn-Mg-coated sheet, Al-Zn-coated sheet, galvanized sheet, coated steel sheet, stainless steel sheet, aluminum alloy sheet, zinc alloy sheet, copper alloy sheet, pure titanium sheet, etc. should be adopted as the base plate;
2 the chemical composition and mechanical properties of common materials shall meet the requirements of Annex B;
3 the coating types of common materials shall be determined according to different environmental corrosion degrees and verified through test, and shall be implemented according to the requirements of A.1.
4.6.2 The structure and thickness of the organic coating on the metal sheet surface shall meet the requirements of Table 4.6.2.
Foreword i
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Basic requirements
4 Metal roofing materials
4.1 General requirements
4.2 Purlin
4.3 Substructure components
4.4 Fixing clips
4.5 Fasteners
4.6 Profiled metal sheet
4.7 Vapor barrier and breather membranes
4.8 Thermal insulation materials
4.9 Sealing materials
4.10 Miscellaneous materials
5 Construction design
5.1 General requirements
5.2 Waterproof and drainage design
5.3 Thermal insulation and moisture-proof design
5.4 Fire protection design
5.5 Lightning protection design
5.6 Sound insulation and noise reduction design
5.7 Weather resistance design
5.8 Temperature deformation design
5.9 Design of attached facilities
5.10 Detailed structural design
6 Structural design
6.1 General requirements
6.2 Load action and effect
6.3 Profiled metal sheet
6.4 Construction requirements
7 Fabrication, transportation and storage
7.1 General requirements
7.2 Fabrication requirements
7.3 Permissible deviation
7.4 Transportation
7.5 Storage
8 Installation
8.1 General requirements
8.2 Installation of substructure components and fixing chips
8.3 Laying of sound insulation and sound absorption layer, vapor barrier, breather membrane and thermal insulation layer
8.4 Installation of profiled metal sheet
8.5 Installation of other components
9 Quality acceptance
9.1 General requirements
9.2 Quality control and inspection batch division requirements
9.3 Safety and function requirements
10 Maintenance and repair
10.1 General requirements
10.2 Maintenance and repair
11 Metal roofing performance testing
11.1 General requirements
11.2 Testing regulations
Annex A Metal roofing performance testing method
A.1 Weather resistance testing method
A.2 Test method for wind driven rain penetration on metal roofing
A.3 External fire protection testing method of metal roofing
A.4 Test method for metal roofing displacement
A.5 Fatigue resistance test of external attachment of metal roofing
A.6 Wind resistance testing method for metal roofing
A.7 Classification and testing method of impact performance of metal roofing against wind-borne debris
A.8 Treading test procedure and method
A.9 Method for wind resistance detection of metal roofing prominent members
A.10 Fatigue resistance test of connecting members
Annex B Chemical composition and mechanical properties of steel, aluminum alloy and stainless steel
Annex C Performance requirements for thermal insulation materials of metal roofing
Annex D Distribution map of wind pressure in strong wind area
D.1 Distribution map of wind pressure in strong wind area in China
D.2 Distribution map of wind pressure in strong wind area in the province
Annex E Schematic diagram for wind sensitive zone and connection details
Annex F Acceptance requirements for inspection quality of raw materials and components
F.1 Site acceptance of raw materials and products
F.2 Manufacture quality acceptance
F.3 Installation quality acceptance
Explanation of wording in the specifications
List of quoted codes