Installer Support
What can happen when a DGU is just bonded to a timber frame . On this case , after the inner pane shattered , the outer pane could have just lifted away from the inner pane in the event of a strong wind . Glass fragments fell into the building below , causing danger to building occupants and the building was no longer secure as the outer pane could just be lifted off the opening . Exposed metal screw heads probably caused the inner pane to shatter in the first place .
Thermal Performance
Approved Document L of the Building Regulations defines the requirements for Conservation of Fuel and Power by setting the standards for energy performance and carbon emissions for new and existing buildings .
This part of the Regulations has recently been updated . In respect of rooflights generally , the limiting rooflight U-value is now 2.2 W /( m 2 K ) when assessed in the horizontal plane . It ’ s important to note that the quoted u-value needs to be for the whole rooflight , not just glass centre pane u-values , which we still see quoted by some suppliers . Even when just a DGU has been bonded to a timber upstand , the centre pane u-value is not the u-value for the installed rooflight as account has to be taken of the spacer bars and edge seal of the sealed unit , the centre pane u-value excludes these heat losses around the edges . A reputable rooflight supplier would be able to provide these accurate values for their product .
Security
Part Q Building Regulations state that ‘ Ground floor , basement and other easily accessible windows ( including easily accessible rooflights ) should be secure windows made to a design that meets the security standards of British standards publication PAS 24:2012 .’
A PAS24 certification is a security standard that can only be met once a product has been certified for its security performance . The acceptable security standard ensures that products meet high-security performance levels , offering reassurance to homeowners that the entry points to their homes have been rigorously tested and are resistant to break-ins and home invasion .
Products satisfying other standards that provide similar or better performance are also acceptable . These standards include : STS 204 Issue 3:2012 ; LPS 1175 Issue 7:2010 security rating 1 ; and LPS 2081 Issue 1:2015 security rating A . Frames should be mechanically fixed to the structure of the building in accordance with the manufacturer ’ s installation instructions .
Other considerations Even a fully compliant , high quality rooflight can be compromised by inappropriate installation methods or standards on site . For this reason , we strongly advise close adherence to manufacturers ’ installation guides and reference to any specific requirements relating to roof finishes abutting the rooflight .
A simple way to ensure that the rooflights you specify for a project will meet appropriate standards and regulations , is to source them from a NARM member company . Our membership comprises businesses supplying all types of rooflights and NARM membership is only open to businesses whose products are fully compliant .
For further information , visit : www . narm . org . uk
The term ‘ rooflight ’ typically refers to a glazed unit installed on a flat roof or where installed on a pitched roof it is likely to be fitted out-of-plane with the level of the roof finish .
CLEARVIEW-UK . COM NOVEMBER 2022
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