Structure: Approved Document A

O N L I N E V E R S I O N A1/2 Section 3: Wall cladding General vehicle barrier, then account should be taken of the additional imposed loading, as stipulated in 3.1 Wall cladding presents a hazard if it Approved Document K, Protection from falling, becomes detached from the building. This collision and impact. section provides guidance on the support and fixing of wall cladding. An acceptable 3.6 Where the wall cladding is required to level of safety can be achieved by different safely withstand lateral pressures from crowds, means depending on the type and location of an appropriate design loading is given in BS EN the cladding. The guidance given relates to 1991-1-1:2002 with its UK National Annex and all forms of cladding, including curtain walling the Guide to Safety at Sports Grounds (4th and glass facades. It is not intended to provide Edition, 1997). guidance concerning the weather resistance Fixings of wall cladding which is included in Approved Document C, Site preparation and resistance 3.7 The selection of fixings for supporting to contaminants and moisture, or guidance on cladding should be determined from a resistance to spread of fire which is included in consideration of the proven performance of the Approved Document B, Fire safety, or guidance fixing and the risks associated with the particular in relation to sound insulation, which is included application. In this regard applications should be in Approved Document E, Resistance to the designated as being either non-redundant (where passage of sound. the failure of a single fixing could lead to the detachment of the cladding) or redundant (where Technical approach failure or excessive movement of one fixing 3.2 The cladding will meet the safety results in load sharing by adjacent fixings) and requirement if: the required reliability of the fixing determined accordingly. a. the cladding is capable of safely sustaining and transmitting to the supporting structure Note: Attention is drawn to the availability of of the building all dead, imposed and wind anchors with an ETA gained in accordance with loads, and the requirements of ETAG 001 Guideline for European Technical Approval Metal Anchors b. the cladding is securely fixed to and for use in Concrete Parts 1-5, which cover both supported by the structure of the building. redundant and non-redundant applications, and This shall comprise both vertical support Part 6 which covers ‘Anchors for multiple use and horizontal restraint, and in non-structural applications’ and which can c. provision is made, where necessary, to effectively be regarded as covering redundant accommodate differential movement of the use. The UK definition of ‘multiple use’ is cladding and the supporting structure of the contained in an annexe to ETAG Part 6 and is building, and framed in such a way that all applications can be validated as to whether or not they conform to d. the cladding and its fixings (including this category without calculation. All ETAG parts any support components) are of durable may be downloaded in English from www.eota.be. materials; the design life of the fixings being not less than that of the cladding. Fixings 3.8 The strength of fixings should be derived shall be corrosion resistant and of a material from tests using materials representative of the type appropriate for the local environment. material into which the fixing is to be anchored, taking account of any inherent weaknesses that Loading may affect the strength of the fixing, e.g. cracks in concrete due to shrinkage and flexure, or voids 3.3 Wind loading on the cladding should be in masonry construction. The design loads will derived from BS EN 1991-1-4:2005 with its UK generally be available from the manufacturer’s National Annex with due consideration given to test data determined from an ETA or an extant local increases in wind suction arising from British Standard. funnelling of the wind through gaps between Note: ETAs are available which cover use either buildings. in both cracked and non-cracked concrete or in 3.4 Where the cladding is required to support non-cracked concrete only. Those which cover other fixtures, e.g. handrails, and fittings, e.g. both cracked and non-cracked concrete allow antennae and signboards, account should be higher loads for use in non-cracked than in taken of the loads and forces arising from such cracked concrete. fixtures and fittings. 3.5 Where the wall cladding is required to function as pedestrian guarding to stairs, ramps, vertical drops of more than 600mm in dwellings or more than the height of two risers (or 380mm if not part of a stair) in other buildings, or as a Structure Approved Document A 38 O N L I N E V E R S I O N