Glazing safety - part N.

Critical location.



In particular locations, glazing materials within doors or associated screens must limit the risk of cutting or piercing injuries in the event of breakage. Part N of the Building Regulations identifies these  ‘critical locations’ and appropriate measures, including use of safety
glass as defined in BS 6206 : 1981.

The 1998 (amended 2000) Edition of Approved Document Part N ‘Glazing – safety in relation to impact, opening and cleaning’ identifies critical locations for glazing within doors and screens: these are shown in the diagram.

APPROVED DOCUMENT N, DIAGRAM 1, CRITICAL LOCATION IN INTERNAL AND EXTERNAL WALLS





In these locations, glazing should:

1) break safely, if at all or
2) be robust or in small panes or
3) be permanently protected.

These requirements are achieved, respectively, by:

1) compliance with test requirements in BS 6206 (that follows)
2) use of inherently strong materials or annealed glass (subject to thickness/area limits), or small panes each no wider than 250mm and larger than 0.5m2
3) an unclimbable, robust screen 800mm high from floor level which prevents a 75mm diameter sphere coming into contact with the glass.



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Safety glass standards and testing.



BS 6206 : 1981 ‘Specification for impact performance requirements for flat safety glass and safety plastics for use in buildings’ describes a test for safe breakage. A sample of the glass is held in a test rig and a loaded bag swung at the glass which passes the test from specific heights. The glass is classified from A to C (with A being most safe) according to the drop height and breakage pattern: A, B or C will comply with Part N requirements.

The result of impact should be limited to:

1) a small clear opening only, with a limit to detached particle size, or
2) disintegration with small detached particles, or
3) breakage with separate pieces (not sharp or pointed)
BS 6206 also requires permanent markings, visible after installation, to include:

1) the BS number (BS 6206)
2) the performance classification (A to C)
3) the glazing material
4) trademark or other identifiable manufacturer’s mark.

In terms of safety, this standard is linked to Part 4 of BS 6262: 1982 ‘Code of practice for glazing in buildings’ which gives recommendations for the design, installation and maintenance of vertical glazing. [BS 6262-4:2005 is ‘Glazing for Buildings. Code of practice for safety related to human impact’– has anyone had a look at this, please?] Part N also requires marking (‘manifestation’) of large areas of uninterrupted glazing, although this does not apply to doors with substantial frames. However, BS 8300 contains more stringent recommendations for marking.

Safety glass standards and testing.



BS 6206 : 1981 ‘Specification for impact performance requirements for flat safety glass and safety plastics for use in buildings’ describes a test for safe breakage. A sample of the glass is held in a test rig and a loaded bag swung at the glass which passes the test from specific heights. The glass is classified from A to C (with A being most safe) according to the drop height and breakage pattern: A, B or C will comply with Part N requirements.

The result of impact should be limited to:

1) a small clear opening only, with a limit to detached particle size, or
2) disintegration with small detached particles, or
3) breakage with separate pieces (not sharp or pointed)
BS 6206 also requires permanent markings, visible after installation, to include:

1) the BS number (BS 6206)
2) the performance classification (A to C)
3) the glazing material
4) trademark or other identifiable manufacturer’s mark.

In terms of safety, this standard is linked to Part 4 of BS 6262: 1982 ‘Code of practice for glazing in buildings’ which gives recommendations for the design, installation and maintenance of vertical glazing. [BS 6262-4:2005 is ‘Glazing for Buildings. Code of practice for safety related to human impact’– has anyone had a look at this, please?] Part N also requires marking (‘manifestation’) of large areas of uninterrupted glazing, although this does not apply to doors with substantial frames. However, BS 8300 contains more stringent recommendations for marking.

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Talk to us to see how we can help you.

Our highly skilled team is always happy to share its technical expertise, whether over the phone or face-to-face.

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