Date: Reference: 12/02/2014 I 36-1.14.4-104/13 English translation authorized by DIBt Original version in German language Approval number: Validity Z-14.4-407 from: 1 February 2014 Applicant: IFBS Europark Fichtenhain A 13a 47807 Krefeld Germany to: 1 February 2019 Subject of approval: Thread-forming screws for fastening of sandwich panels to steel or timber supporting structures The subject of approval mentioned above is herewith generally approved in the field of construction. This allgemeine bauaufsichtliche Zulassung comprises eight pages and 31 Annexes *). This allgemeine bauaufsichtliche Zulassung replaces the allgemeine bauaufsichtliche Zulassung Z-14.4-407 of 23 November 2011, amended by notification, dated 8 April 2013. An allgemeine bauaufsichtliche Zulassung (national technical approval) was granted for this construction product for the first time on 18 June 1996. *) The number of pages and Annexes refers to the original approval of 12 February 2014 without later amendments
Page 2 of 8 12 February 2011 I GENERAL PROVISIONS 1 With the allgemeine bauaufsichtliche Zulassung the fitness for use and the applicability of the subject of approval according to the Landesbauordnungen ('Building Regulations of the Land') has been verified. 2 If, in the allgemeine bauaufsichtliche Zulassung requirements are made concerning the special expertise and experience of persons entrusted with the manufacture of construction products and types of construction according to the relevant regulations of the Land following section 17, sub-section 5 Musterbauordnung ('Model Building Code'), it is to be noted that this expertise and experience can also be proven by equivalent verifications from other Member States of the European Union. If necessary, this also applies to verifications presented within the framework of the Agreement on the European Economic Area (EEA) or other bilateral agreements. 3 The allgemeine bauaufsichtliche Zulassung does not replace the permits, approvals and certificates prescribed by law for carrying out building projects. 4 The allgemeine bauaufsichtliche Zulassung will be granted without prejudice to the rights of third parties, in particular private property rights. 5 Notwithstanding further regulations in the "Specific Provisions" manufacturers and distributors of the subject of approval shall make copies of the allgemeine bauaufsichtliche Zulassung available to the user and point out that the allgemeine bauaufsichtliche Zulassung has to be available at the place of use. Upon request copies of the allgemeine bauaufsichtliche Zulassung shall be placed at the disposal of the authorities involved. 6 The allgemeine bauaufsichtliche Zulassung may be reproduced in full only. Publication in the form of extracts requires the consent of Deutsches Institut für Bautechnik. Texts and drawings of advertising brochures may not be in contradiction to the allgemeine bauaufsichtliche Zulassung. 7 The allgemeine bauaufsichtliche Zulassung is granted until revoked. The provisions of the allgemeine bauaufsichtliche Zulassung ('national technical approval') can subsequently be supplemented and amended in particular, if this is required by new technical findings.
Page 3 of 8 12 February 2011 II SPECIFIC PROVISIONS 1 Subject of approval and field of application Subject of approval are thread-forming screws made of steel for regular load bearing connections of flat, ripped or profiled sandwich panels with steel or timber supporting structures. The core of the sandwich panel shall be made of polystyrene (PS) - or polyurethane (PUR) ridged foam or mineral fibre with a minimum compression resistance of the core of 0.04 N/mm² (according to the information to the sandwich panels e. g. in CEmarking) The thread-forming screws are divided into (see also Annex 1): - Self-drilling screws with a drill-bit where drilling of the hole, forming the female thread and screwing-in are realised in one working step, - Sharp-point screws where forming of the hole by material extrusion (extrusion drilling) and tapping of the counter thread are done in one operation. - self-tapping screws which tap their female thread non-cutting into an existing matching hole. The screws are used for steel supporting structures as well as for timber supporting structures. This approval specifies the connections executed with the screws for predominantly static loads. 2 Characteristics of the construction product 2.1 Characteristics and composition 2.1.1 Dimensions The main dimensions (nominal dimensions) are given in the Annexes. Further information with regard to the dimensions and tolerances are deposited at Deutsches Institut für Bautechnik. 2.1.2 Materials 2.1.2.1 General For the materials of the fastening elements and the structural components to be connected the details in the Annexes apply unless otherwise stated in the following. 2.1.2.2 Fastening elements Screws or washers according to the respective Annexes of this allgemeine bauaufsichtliche Zulassung ( national technical approval ) consisting of stainless steel grade A2 according to allgemeine bauaufsichtliche Zulassung ( national technical approval ) Z-30.3-6 (e. g. 1.4301 or 1.4567) may be made of stainless steel grade A4 (e. g. 1.4401 or 1.4578) as well. 2.1.3 Corrosion protection 2.2 Marking Screws partly or completely exposed to external weather or a similar corrosion load shall be made of stainless steels. This does not apply to maybe welded-on drill-bits or tips of sharppoint screws. The corrosion protection of fastening elements not made of stainless steel shall be adapted to the required corrosion protection of the components to be connected by galvanizing and if necessary by coating as well. The rules given in DIN EN ISO 4042:2001-01 shall be taken into account. The thickness of the galvanic layer shall be at least 8 µm. The package of the screws or the enclosed leaflet shall be marked by the manufacturer with the conformity mark Ü (Ü-mark) according to the Übereinstimmungszeichen-Verordnungen
Page 4 of 8 12 February 2011 der Länder ('Regulations on the conformity mark of the states of the Federal Republic of Germany'). The marking may only be applied if the requirements according to Section 2.3 have been met. Every package shall have an additional label with information about the factory (factory code), the description, the geometry and the material of the screws. Every screws shall have an additional head mark (manufacturer s mark). 2.3 Verification of conformity 2.3.1 General Proof of conformity of the construction product manufactured according to this national technical approval, with the provisions of this national technical approval, shall be delivered by means of a certificate of conformity issued for each manufacturing plant and based on factory production control and continuous surveillance including initial-type testing of the construction product in accordance with the following provisions. The manufacturer of the construction product shall involve an accredited certification body and an accredited monitoring body for the issuing of the certificate of conformity and for the outside monitoring, including the related product inspections. The declaration that a certificate of conformity has been granted shall be given by the manufacturer by marking the construction products with the mark of conformity (Ü-Zeichen) ('Ü mark') stating the intended use. The certification body shall submit, for information, a copy of the relevant certificate of conformity to the Deutsches Institut für Bautechnik. For the scope, way and frequency of the factory production control and the continuous surveillance by a notified body the "Zulassungsgrundsätze des Deutschen Instituts für Bautechnik für den Übereinstimmungsnachweis für Verbindungselemente im Metallleichtbau" (see issue 6/1999 of "DIBt Mitteilungen") apply. 2.3.2 Factory production control Every manufacturing plant shall have a factory production control system and exercise factory production control. Factory production control means the permanent control of production exercised by the manufacturer by which the latter ensures that the construction products produced by him are in conformity with this national technical approval. The results of factory production control shall be recorded and evaluated. The records shall include at least the following information: - designation of the construction product or the initial materials and the components - type of control, - date of manufacture and date of testing of the construction product or the initial materials and the components, - results of control and comparison with requirements deposited at DIBt, - signature of the person responsible for factory production control. The records shall be kept for at least five years and shall be presented to the inspection body involved in surveillance. On request, they shall be presented to the Deutsches Institut für Bautechnik and to the relevant supreme building authority. In case of unsatisfactory test results the manufacturer shall immediately take the measures necessary to rectifying the fault. Construction products not meeting the requirements shall be handled in a way that confusion with the products in compliance with the specifications will be excluded. As soon as the fault has been rectified as far as technically possible and required for evidence that the fault has been rectified the corresponding test shall be repeated immediately.
Page 5 of 8 12 February 2011 2.3.3 Surveillance Factory production control exercised in every manufacturing plant shall be continuously verified by surveillance, but at least once a year. In the framework of surveillance, an initial-type testing of the construction product shall be performed and also samples can be taken for audit-testing. Sampling and testing are in the responsibility of the approved body. The results of the certification and surveillance shall be kept for at least five years. On request, it shall be presented by the certification body or inspection body to the Deutsches Institut für Bautechnik and to the relevant supreme building authority. 3 Provisions for design and calculation 3.1 Design In the following and in the Annexes the structural components to be fastened are called component I and the supporting structure or base material are called component II (see also Annex 1). Furthermore the following symbols are used: d or D Thickness of the sandwich panel (see Annex 1) t N1 t N2 u Thickness of the outer face (top plate on the side of the screw head) Thickness of the inner face (bottom plate on the side of the supporting structure) Head displacement (measured from screw axes) For calculation of shear resistance of the connection the value for the plate thickness t N2 shall be used as relevant. For calculation of tension resistance of the connection and pullover the relevant thickness is plate thickness t N1. 3.2 Calculation 3.2.1 General The verification concept given in DIN EN 1990:2010-12 in connection with the National Annex applies. For the calculation of the acting tension and shear forces as well as the head displacement, the respective standards apply as e. g. the applicable standards of the Euro Code or the Specific Provisions of the allgemeine bauaufsichtliche Zulassungen ('national technical approvals') for sandwich panels. Annex 1 of this approval shows the kinds of loading 3.2.2 Characteristic values of resistance For the different screws the characteristic values of tension resistance N R,k and shear resistance V R,k shall be taken from the Annexes of this national technical approval. For intermediate thicknesses of component I or component II the characteristic value for the thinner component shall be taken. The characteristic values of tension resistance in the respective Annexes shall be reduced to 70 % for thin-walled asymmetric supporting structures with plate thicknesses smaller than 5 mm (with no axes of symmetry parallel to screw axes as for e. g. Z - or C profiles). 3.2.3 Additional rules for connections with timber supporting structures Timber supporting structures shall be made of pine timber of at least the strength class C24 according to DIN EN 14081-1:2011-05 in connection with DIN 20000-5:2012-03 or of gluedlaminated timber according to DIN EN 14080:2013-12. The additional rules for connections of sandwich panels with timber supporting structures of this clause do only apply to screws where in the Annexes is referred to this clause. DIN EN 1995-1-1:2010-12 in connection with the National Annex DIN EN 1995-1-1/NA:2010-12 apply unless no other provisions are made in the following. The following terms are used:
Page 6 of 8 12 February 2011 d l g - nominal screw diameter (is equal to the external thread diameter) - screw-in length part of thread extended into component II inclusive probably existing tip or drill bit. l g = L - t 1 - s M - s K l - screw length t 1 - thickness component I (for more components to be fastened t 1 = Σ t 1,i applies) s M - thickness of the metal part of the sealing washer s K - thickness of the sealing of the sealing washer l ef - effective screw-in length (equal to penetration depth of the threaded part) l ef = l g l b with l ef 4d l b - length of the unthreaded part of the drill bit (l b = 0 for screws without drill bit and l b = d for sharp-point screws) N R,k = F ax,rk k mod V R,k = F v,rk k mod F ax,rk = F ax,α,rk for α = 90 F ax,α,rk acc. DIN EN 1995-1-1:2010-12, equation (8.40a) F v,rk acc. DIN EN 1995-1-1:2010-12, clause 8.2.3, equation (8.9) k mod acc. DIN EN 1995-1-1:2010-12, Table 3.1, as far as no other values are given in DIN EN 1995-1-1/NA:2010-12, Table NA.4 for glued-laminated timber, ply wood and solid timber panels f h,k = acc. DIN EN 1995-1-1:2010-12, equation (8.16) M y,rk in equation (8.9) shall be obtained from the respective Annexes to this allgemeine bauaufsichtliche Zulassung. As far as no values are given in the Annexes, M y,rk may be calculated as follows: M y,rk = 0.3 f u (1.1 d k ) 2.6 [Nmm] d k d k f u f u - thread core diameter, if no values are given it may be calculated in approximation = 0.7 d - tensile strength of the wire the screws are made of. The following value may be used without further verification: = 500 N/mm² f ax,k in equation (8.40a) shall be taken from the respective Annexes to this allgemeine bauaufsichtliche Zulassung. The partly declared values in the Annexes for the pull-out parameter f 1,k according to DIN 1052 may be used alternatively for calculation. As far as no values are given in the Annexes, f ax,k may be calculated in approximation f ax,k = 70 10-6 ρ 2 k [N/mm²] ρ k ρ k - characteristic raw density of the timber structure in kg/m³, ρ k 500 kg/m³ = 350 kg/m³ for strength class C24 The characteristic values for tension resistance N R,k (pull-out timber structure) and shear resistance V R,k (bearing resistance timber structure) for component II, calculated according to clause 3.2.3 shall be compared with the characteristic values N R,k (pull-through) and shear
Page 7 of 8 12 February 2011 resistance V R,k (bearing resistance) for component I obtained from the respective Annexes. The lower value shall be used for further calculations. 3.2.4 Design values of resistance For the calculation of the design values of resistance from the characteristic values the following applies: N R,d = V R,d = N V R,k M R,k M with γ M = 1.33 3.2.5 Combined tension and shear forces For combined acting design tension forces N and design shear forces V the following verification procedure for interaction applies: N N R,d + V V R,d 1.0 3.2.6 Proof of screw head displacement It shall be proofed that the screw head displacements due to temperature expansion of the top plate do not exceed the maximum values for screw head displacement u given in the Annexes. For intermediate values of the sandwich panel thickness d or D zul u (allowed value for u) may be interpolated..for intermediate values of component thickness t II max. u shall be chosen for the bigger component thickness. The displacement of the top plate due to atmosphere temperature change shall be calculated in according to the provisions of the allgemeine bauaufsichtliche Zulassungen ('national technical approvals') for sandwich panels. The reduction resulting from restraint stresses according to the linear sandwich panel theory may be considered. 4 Provisions for execution Connections in accordance with clause 1 shall only be executed by companies with the necessary experience unless the instruction of the assembly personnel is arranged by specialists experienced in this field. It is to guarantee by the execution that no bimetallic corrosion can occur. Screws with washers and EPDM sealing rings exposed to external weather shall be screwed-in with electric screw driver with appropriate set depth stop. The use of impact wrenches is basically not allowed. The fastening elements shall be fixed rectangular to the surface of the components to guarantee a correct load bearing and if necessary rain-proof connection. Component I and component II shall be in contact to each other in the connection area. The use of compression resistant thermal insulation strips up to a thickness of 3 mm is allowed. During installation of fastening screws admissible for timber substructures, except selfdrilling screws, the components I and II which shall be connected shall be predrilled with 0.7 d as long as no other instructions are given in the Annexes. The effective screw-in length for timber supporting structures shall be least 4 d unless no larger values are required in the Annexes or in the execution plans (layout drawings).
Page 8 of 8 12 February 2011 Fastening screws for steel supporting structures shall be screwed-in with the cylindrical part of the thread - through the material if component II has a thickness up to 6 mm and - at least 6 mm if component II has a thickness of over 6 mm. Welded drill bits or hardened tips shall therefore not be taken into account. Connections of sandwich panels to supporting structures shall be executed in accordance with the instructions for installation given in the Annexes and if applicable under consideration of the Specific Provisions of relevant allgemeine bauaufsichtliche Zulassungen ('national technical approvals') for sandwich panels and of the existing technical building regulations. The manufacturer s information about the maximum clamp length shall be considered. Already loaded screws in regular load bearing connections shall only be replaced by thread forming screws with a larger diameter. Therefore the hole has to be predrilled for the thicker fastening screw. Andreas Schult Head of section Beglaubigt ( confirmed ) Ulbrich
( national technical approval ) of 12 February 2014 Hilti Thread-forming cartridge fired screws pins X-CR for fastening 14P8 made of sandwich of corrosion panels resistant to steel steel or timber supporting for structures fastening of attachment profiles for building facades Examples for screws Example Dimensions of execution of the cartridge of a connection fired pins, materials, fastening tool, cartridge loads Loading conditions Annex 1