Colorcoat® Column: Gauges

What impact does the ordered gauge have on the structural performance of profiled pre-finished steel cladding?

The structural performance of a pre-finished steel profiled sheet is dependant upon 3 factors:
1.shape/geometry of the profile
2.gauge of the steel substrate
3.mechanical properties of the steel grade used.

Gauges and tolerances

EN10143:2006 specifies the maximum and minimum actual gauge, which is permissible for a nominal ordered gauge.
For example a 1250 mm wide 0.7 mm coil must be supplied within the gauge range 0.64 mm to 0.76 mm.
It should be noted that the tolerances quoted in the current 2006 version of this document are slightly tighter than those quoted in the previous document, so the specifier should ensure that material is supplied to the correct standard.
Ordering material with a lighter nominal gauge than 0.7 mm, but within the apparent tolerance range, may result in material actually produced being less than 0.64mm. The structural performance of the profile will consequently be reduced.
All Colorcoat® pre-finished steel meets the requirements of EN10143:2006.

Mechanical properties of the steel substrate

All Colorcoat® pre-finished steel for wall and roof cladding is supplied with a specified minimum yield strength. This figure is used to calculate the structural performance of the profiled pre-finished steel sheet. In practice, the actual yield point will generally be significantly greater than the minimum value, resulting in a profiled pre-finished steel sheet with a greater resistance to stress failure.

 “How do I ensure the correct structural performance of the pre-finished steel sheeting?”

Load span tablesLoad span tables are used to calculate the maximum permissible purlin spacing at which the profiled sheeting will meet the structural requirements for the building location and application.
All Corus Colors supply chain partners have load span tables that have been calculated according to EC3 and have been independently assessed and approved by the Steel Construction Institute. (SCI Assessed)
The load/spans quoted in these tables are specific to the exact profiles and material specifications supplied by these profilers and cannot be applied to different profiles or material grades/gauges.

 

CE marking

CE-marking is a European product information label that indicates that the properties of the product have been tested according to European standards. The European Commission has determined which properties for which building products in the EU are relevant and should be tested and what external verification is appropriate.  The values of the tested properties have to be stated/printed by the producer on the product, the packaging or the accompanying coupon. Country supervisors inspect randomly if CE-marks on products are complete and correct.
All Corus Colors supply chain partners are able to supply CE marked pre-finished steel profiled sheeting, which meets the requirements of EN 14782.

New BREEAM Technical Paper

Corus has announced the publication of a new technical paper – ‘An Introduction to BREEAM for pre-finished steel industrial buildings’ – which takes an in-depth look at this environmental assessment method, and provides specifiers, building owners and clients with a comprehensive understanding of the benefits of having industrial buildings assessed within the BREEAM scheme.

BREEAM (Building Research Establishment’s Environmental Assessment Method) is the UK’s leading and most widely used environmental assessment for buildings. Developed in the early 1990s, it is based on many years of construction and environmental research and is validated by input from the construction and property industries, the government and building regulators.

The BREEAM scheme is used to assess the environmental impacts arising as a result of an individual development at the design and post-construction stages.  The post-construction review serves to confirm the interim assessment (done at the design stage) and, most importantly, that the ‘as built’ performance matches that envisaged at the design stage.

Corus’ technical paper focuses on how to achieve BREEAM ratings for industrial buildings. It also demonstrates how the incorporation of Colorcoat® pre-finished steel into the specification for both roof and wall cladding systems can maximise the credits assessed under the energy, materials and waste categories.

The sustainable attributes of pre-finished steel  roof and wall cladding systems can contribute to achieving a good overall BREEAM score, and given the synergy of pre-finished steel building envelopes with a structural steel frame  (which is also highly regarded under BREEAM) the case for steel is clear.

Carlton Jones, Technical Development Manager of UK Construction at Corus Colors, comments: “The purpose of this paper is to give a clear overview of what BREEAM is and how it is assessed as well as providing guidance on how to achieve its ratings. Corus has a well-established reputation for providing specifiers with comprehensive advice and guidance to support the design and construction of the pre-finished steel building envelope. Working together with the Steel Construction Institute (SCI) we have endeavoured to explain BREEAM and how the specification of the building envelope forms an important part of the key issues that can contribute to a good BREEAM score.”

Click here to download the paper

CE Marking, BREEAM and BS476 info updated..

I’ve just updated the colorcoat-online site with new info:

CE Marking

New updated info on CE Marking for self supporting metal profiled sheets

Breeam information

New section on BREEAM (Buildings Research Establishment’s (BRE) Environmental Assessment Method) – the UK’s leading and most widely used environmental assessment method for buildings.

BS476 information

This section has been brought back from the old site, as BS476 (fire info) was popular on the old site.

Colorcoat Technical Paper validated by SBEM

The latest revision of Part L was launched in April 2006 amongst much confusion in the construction industry.  The non-domestic part (ADL2A) of the regulations is now reliant on a whole-building carbon emissions calculation carried out by a piece of software known as SBEM.  SBEM is continually being updated by the BRE and Version 3.01 of SBEM was launched on the 12th of February 2008. 

This latest version of SBEM implements, for the first time, one of the fundamental aspects of Part L – that buildings should be designed so that they do not overheat.

One of the important balancing acts to be achieved when designing to the latest Part L is in specifying level of natural lighting.  Of course, natural lighting helps to make the building comfortable and if matched by a good lighting control system, can help to minimise energy usage too.  However, the problem with natural light is that it tends to come alongside natural heat, better known as solar gain.

In our Colorcoat Technical Paper, “In-plane rooflights for low energy buildings” Corus demonstrate how the effects of light and heat can be balanced-out by using a proportion of rooflights in single-storey buildings. 

Whilst some have been calling for 15% or even 20% of roofs to be transparent, the results reported in the paper show that this can lead to overheating of buildings. Now, for the first time, the requirement to avoid overheating has been included in SBEM and this is completely in line with the results reported in the Corus Colorcoat Technical Paper. 

“This is great news” says Ian Clarke, Applications Development Manager at Corus.  “When we studied the effects of these high levels of rooflights, we knew it was wrong and that buildings would be overheating.  The fact that the latest version of SBEM has included this is really important for designing buildings which are comfortable to occupy at the same time as producing very low carbon emissions.  It also provides some valuable external validation for the work which we have done.”

The Colorcoat Technical Paper “In-plane rooflights for low energy buildings” which is certified as Core Curriculum for RIBA CPD is avaliable to download here or can be obtained from the Colorcoat Connection helpline.

Colorcoat Urban™ in Action – Open Day

See Colorcoat Urban™ in Action at the University of Nottingham on the 20th or 21st of February 2008. If you’re an architect, planner or developer in the UK, Click here to register your interest.

The Day will include presentations from key partners (Logix, Rehau and BASF) and a tour of the Sustainable house which uses Colorcoat Urban™ on the roof.