CEN/TC 33/WG 6 N 490. doc.wg Question table for determining structural/non structural steel and aluminium component in building envelope.

Transcription

1 CEN/TC 33/WG 6 N 490 CEN/TC 33/WG 6 CEN/TC 33/WG 6 - Curtain walling of secretary: Secretariat: UNI (Italy) doc.wg Question table for determining structural/non structural steel and aluminium component in building envelope. Document type: Date of document: Other committee document Expected action: INFO Background: Committee URL:

2 CEN TC 33 WG6 doc. N Question table for determining structural/non structural steel and aluminium component in building envelope. Scope: The Standing Committee of Construction, presented on June 2014 the document below to define in more detail products which are falling under the scope of hen The coexistence period of hen ended the 1st of July. As it is clearly mentioned on point B.3 facade systems which have no structural function, fall out of the scope of this document. In order to harmonise the way our sector operates, WG6 decided to run a survey across its members and observers asking their point of view and if needed summarize with a CEN/TC 33 decision the outcome. The scope of hen deals with Steel and Aluminium construction. As (transparent) facade systems may be also manufactured from other type of framing members (e.g. timber), participants are entitled to respond for the structural behaviour of any different framing materials that may be used and not only focus on Steel and Aluminium technical solutions that are addressed in the SCC document Before forwarding the conclusion of WG 6 to TC 33, WG6 members and observers will get the entire set of conclusions for their information. (see attachment 1) Additional necessity to clarify the situation: On CEN/TC 250/SC 9 dealing with all Eurocode standards related to Aluminium, there is the willing to develop a new European Norm dedicated to 'Design methodologies and structural details for the combination of aluminum and glass in structures' (below enclosed Answer to the Mandate M515 - page 110/138 of the PDF). For this reason, WG 6 has an additional reason to investigate the necessity for such an attempt by defining what/whether something should be considered as relevant for CEN/TC 250. (see attachment 2)

3 1a: curtain walling Do you agree that curtain walling applied in vertical, but also the sloping parts included in the vertical curtain walling, should be considered as non-structural as they are usually designed as self-supporting constructions which transmit dead-loads, imposed loads, environmental load (wind, snow, etc) and seismic load to the main building structure and for this reason in the majority of applicable cases, curtain walling has no structural function and shall be CE marked, as a kit, according to EN 13830? Steel or aluminium elements, part of the building structure, which carry the load of the curtain walling, shall be CE marked according to EN b: curtain walling with reinforced framework Do you agree that curtain walling with framework which section is reinforced by steel or aluminium plate has no structural function and it shall be CE marked as part of the curtain walling kit according to EN 13830?

4 1c: curtain walling with composite framework Do you agree that curtain walling with framework which section is composed by an aluminium profile that carries the glazing and an additional steel or aluminium profile that works as framework has no structural function and it shall be CE marked as part of the curtain walling kit according to EN 13830? 1d: curtain walling brackets and cleats Do you agree that curtain walling brackets, which are connecting the curtain walling to the structure, and cleats, which are connecting together the framing elements, have no structural function and shall be CE marked as part of the curtain walling kit according to EN 13830?

5 1e: curtain walling with shading devices Quite often, curtain walling incorporates permanent loads, which are transferred to them by complementary ones (e.g. shading systems). Do you agree that in the majority of such cases those additional loads should not change the consideration of the curtain walling from non-structural to structural? In case you disagree with the above statement, please present examples where the product should be considered as structural.

6 2a: curtain walling fixed to a dedicated secondary structure For curtain walling applied in vertical, but also the sloping parts included in the vertical curtain walling, where a dedicated secondary structure (e.g. made out of steel) is used to carry loads from the curtain walling, do you agree that in general the curtain walling should be considered as non-structural and shall be CE marked as a kit according to EN 13830? In this case the curtain walling is not different from case 1), what is changing is just the missing of the main building structure (e.g. slab) to support the curtain walling, that is why a dedicated secondary structure (connected to the main structure of the building) shall be used. Steel or aluminium elements, part of the main or secondary structure, which carry the load of the curtain walling, shall be CE marked according to EN

7 2b: curtain walling not fixed to the main building structure or a dedicated secondary structure For curtain walling applied in vertical, but also the sloping parts included in the vertical curtain walling, which are not fixed neither to the main building structure, neither to a dedicated secondary structure, but the framework of the curtain walling itself become the structure of the building, do you agree that in general the framework of the curtain walling should be considered as structural and it shall CE marked according to EN ? (e.g. wintergarden)

8 3a: systems for glazed canopies Do you agree that systems for glazed canopies (or glazed roofs for entrances) should be considered as nonstructural because in the majority of cases a supporting structure is introduced to carry the loads? Steel or aluminium structural elements not part of the glazed system, which carry the load of the canopy, shall be CE marked according to EN 1090.

9 3b: skylights Do you agree that systems for skylights (or roof glazings) should be considered as non-structural elements when they are supported by the main structure of the building (structural roof). In most of the cases skylights are made by using the same systems for curtain walling. Steel or aluminium elements, part of the main or secondary structure, which carry the load of the skylight, shall be CE marked according to EN c: Roof glazings On the contrary, do you agree that elements of skylights (or roof glazings) should be considered as structural elements when they are in fact the main structure of the building (structural roof) and they shall be CE marked according to EN ?