Regulations

Fire Performance

Building Regulations Approved Document B (2000 edition) sets out the rules for fire safety of buildings. Section B2 covers internal fire spread, and applies to the linings of both the roof and walls of buildings. In general these are surface spread of flame requirements to BS476 Part 7 (typically Class 1 and Class 3). Section B4 covers external fire spread and applies to external coverings or roofs and walls; in general these are fire resistance requirements to BS476 Part 3 (typically AA and AB).

Lonsdale aluminium patent glazing systems are designated Fire Resistance AA – see the section on fire under Design here​

Safety

Only certain glass types are suitable for overhead glazing. Please see Glass Types under the Design Considerations page for further information

The Health and Safety at Work Act and the Construction (Design and Management) Regulations 1995, both require that worker safety should be addressed within the design of a building. This applies during the construction of the building and, once built, its maintenance, repair and demolition.

It is the responsibility of the designer of the building to assess what the risks are. These may be categorised as follows:

Class 0 Roofs design for unrestricted access including members of the public

Class 1 Roofs which may need to be walked on from time to time for cleaning or maintenance issues and must therefore support the weight of both people and their equipment.

Class 2 Roofs where people are not intended to walk on the glass, but are required to be non-fragile in case of falling onto the glass whilst walking adjacent or from crawling boards or other access equipment.

Class 3 Roofs that are fragile where there is no risk of falling onto the glass or un-authorised access. A guard rail preventing this may suffice in most circumstances to protect anybody walking walking adjacent to the rooflight during cleaning/maintenance.

The HSG33 Health and Safety in Roof Work booklet specifically states that:

Where rooflights are required, it is obligatory for designers to consider -

  • Specifying rooflights that are non-fragile
  • Fitting rooflights designed to project above the plane of the roof and which cannot be walked on (these reduce the risk but they should still be capable of withstanding a person falling onto them)

Further advice can be gained from our Technical Department via info@lonsdalemetal.co.uk or Tel 020 8801 4221

CE Markings

Currently, other than opening rooflights intended for smoke ventilation to EN12101 or single pane roof windows (Velux or similar) to EN14351, there is no Harmonised European Standard (hEN) applicable to glass rooflights, therefore CE Marking is not mandatory. For further guidance, please see highlighted paragraph on page 2 of relevant publication by NARM The National Federation of Rooflight Manufacturers.

Click here to view NARM The National Federation of Rooflight Manufacturers guidelines.

Thermal Performance and Air Leakage

​The Government is committed to the reduction of greenhouse gases as a result of the Kyoto agreement on Climate Change. The Building Regulations for England, Wales and Scotland, which cover Conservation of fuel and power, have been updated accordingly. The revised Regulations require buildings to:

  • Have more insulation in the building envelope.
  • To limit heat loss from pipes and ducts.
  • To provide more energy efficient lighting, heating, cooling and ventilation systems.

In the drive for energy efficiency the revised Regulations set minimum acceptable levels for natural daylighting and refer to CIBSE LG10 for additional guidance. That publication explains the value of natural daylight on human performance and thus on energy efficiency in its widest sense. Widespread research links natural daylighting to tangible work place benefits: improved retail sales, lower staff absenteeism, faster hospital recovery rates, and improved school exam results.

Natural lighting should be provided in all buildings. Windows can provide daylight to areas within 6 metres of a window, but rooflights are the only practical means of introducing daylight to any wider buildings.

CDM and Non Fragility

The Health and Safety at Work Act and the Construction (Design and Management) Regulations 1995, both require that worker safety should be addressed within the design of a building. This applies during the construction of the building and, once built, its maintenance, repair and demolition.

The HSG33 Health and Safety in Roof Work booklet specifically states that where rooflights are required, it is obligatory for designers to consider:

  • Specifying rooflights that are non-fragile.
  • Fitting rooflights designed to project above the plane of the roof and which cannot be walked on (these reduce the risk but they should still be capable of withstanding a person falling onto them).

Rooflights, lanternlights and patent glazing should be classified to ACR[M] 001:2014 Red Book test procedure. Consideration to prEN1873 is also required (using 1200joules energy rating).

Lonsdale systems have been tested by BRE and have been classified Class A and Class B. Details of the tests are available on request.

Alternatively, rooflights may be deemed non-fragile if they comply with the requirements of TN92 from the Centre for Window and Cladding Technology (CWCT).

For rooflights outside the scope of TN92, testing is required to TN66 and TN67 - please contact us for advice.

Even non-fragile rooflights are susceptible to damage by impact. They are not usually intended to support foot traffic. Crawling boards must be used – please refer to our Cleaning and Maintenance Manual

It must be stressed that different combinations of bar lengths and centres will produce varying results. Please contact our Technical department for guidance.

British Standards

Main
BS 5516-1 Code of practice for design and installation of sloping and vertical patent glazing.
BS 5516-2 Patent Glazing and Sloping Glazing for Buildings

Design & Safety
BS 6262-4 Glazing for buildings. Safety related to human impact.
BS 6399 Parts 1 & 2 Loading for buildings.
BS 8118-1 Structural use of aluminium. Code of practice for design.
BS 8213-1 Windows, doors and rooflights. Code of practice for safety in use and during cleaning of windows including door height windows and roof windows.
BS EN 14024 Metal profiles with Thermal Barriers – Mechanical Performance – requirements, proof, tests
CP 153-2 Windows and rooflights. Durability and maintenance.

Finishing
BS 6496 Specification for powder organic coatings for application and stoving to aluminium alloy extrusions, sheet and preformed sections for external architectural purposes, and for the finish on aluminium alloy extrusions, sheet and preformed sections coated with powder organic coatings.
BS EN 12206-1 Paints and Varnishes. Powder Coating of Aluminium and Aly Alloys for Architectural

Fittings & Fasteners
BS EN ISO 3506-1 Mechanical properties of corrosion-resistant stainless-steel fasteners. Bolts, screws and studs.
BS 3382 Specification for electroplated coatings on threaded components.
PD 6484 Commentary on corrosion at bimetallic contacts and its alleviation

Gaskets & Sealants
BS 2571 Specification for general-purpose flexible PVC compounds for moulding and extrusion.
BS 4255-1 Rubber used in preformed gaskets for weather exclusion from buildings. Specification for non-cellular gaskets.
BS EN ISO 11600 Building Construction – Jointing Products, classification and requirements for Sealants

Glass
BS 952-2 Glass for glazing. Terminology for work on glass.
BS 6206 Specification for impact performance requirements for flat safety glass and safety plastics for use in buildings. Note BS6206 replaced by BS EN 12600 for glass testing.
BS EN 12600 Pendulum test – impact test method for flat glass

Aluminium
BS EN 485 Parts 1 to 4 Sheet, strip and plate
BS EN 755 Parts 1 to 9 Extruded rod/bar, tube and profiles
BS EN 12020 Parts 1 & 2 Extruded precision profiles in alloys EN AW-6060 and EN AW-6063 ​

Design Considerations