NEW GLASS BARRIER REQUIREMENTS FROM 1 JUNE 2016
See update below
New Standard leads to new Acceptable Solution
In last month's Notes, we stated that Masterspec sections now referred to the new Glazing Standards and that they were not Acceptable Solutions. The ink had barely dried when MBIE released Building Control Update 183 - Glass Barrier Requirements to be amended 1 June 2016.
As you know from last month, among others the old Standard 'NZS 4223.3: 1999 - Glazing in buildings - Human impact safety requirements' has been replaced by NZS 4223.3: 2016 - Glazing in buildings - Human impact safety requirements. MBIE have moved quickly to use the new Standard for glass barriers and brought it into force using Building Control Update 183.
Building Control Update 183 states:
On 1 June 2016 Ministry of Business Innovation & Employment will amend the glass barrier requirements in the acceptable solution B1/AS1, to those requirements in NZS 4223.3:2016. The current glass barrier requirements in B1/AS1 will cease to have effect at the same time.
Although complete technical information has not been released to date, Masterspec believes this means the adoption of NZS 4223.3: 2016, section 22 BARRIERS (BALUSTRADES, FENCES, AND SCREENS).
Glass screens, balustrades and pool fences
In NZS 4223.3: 2016 glass type varies with glazing system and situation. The situation largely hinges around safety from falling, that is a fall less than (<) 1000mm or a fall equal or greater than (≥) 1000mm.
The three major situations are:
No fall or a fall <1000mm, with any type of glazing system:
- As the fall is <1000mm these are not classified as Barriers to NZBC F4/AS1.
- Pool fences must still be to the Fencing of Swimming Pools Act 1987.
- Glass thickness may be affected by wind loading.
- Glazing system can be glass infill panels (full or part framed) or structural glazing.
- Glass type to be Toughened Safety Glass or Laminated Safety Glass (Laminated can be annealed, heat strengthened or toughened)
- Refer to NZS 4223.3, in particular 22.1 General and 22.2 Glazing Not Safeguarding a Fall.
Fall ≥1000mm with glass infill panels:
- Glass infill panel requires a frame consisting of at least two posts and a top rail (more rails are possible) with glass fixed to at least 2 opposite sides, refer NZS 4223.3, 22.4.1 and 22.4.2.
- Glass type to be Toughened Safety Glass or Laminated Safety Glass (Laminated can be heat strengthened or toughened)
- Refer to NZS 4223.3, in particular 22.3 Glazing Safeguarding a Fall and 22.4 Glass Barrier (balustrade) types.
Fall ≥1000mm with structural glazing:
- Glass Type, with interlinking rail to be Toughened Safety Glass or Laminated Safety Glass (Laminated to be heat strengthened or toughened)
- Glass Type, without interlinking rail to be Heat Strengthened Laminated Safety Glass or Toughened Laminated Safety Glass.
- Without an interlinking rail laminated glass must have either a top cap, or supports that can retain it in place if broken, or alternatively a stiff interlayer capable of preventing collapse. These will probably need manufacturers input, as not a lot of testing has been done at this stage.
- Refer to NZS 4223.3, 22.4.3 Structural Glass Barriers and/or the manufacturer.
Interlinking Rail definition from NZS 4223.3, 1.6:
- A rail (normally used with glass barriers) that is connected to each glass pane or to a structural post or other building element. They shall resist the serviceability limit state (SLS) line and concentrated loads in the event of a glass pane breakage.
Note; interlink rails may also act as handrails (or not).
Masterspec have updated the glass and related sections in line with these requirements. But with a lack of complete detail from MBIE it will pay to be cautious until we know more. The speed in which MBIE have adopted the new Standard and Acceptable Solution means the industry will take some time to catch up with products and testing. If you are planning to use Structurally Glazed Barrier, Masterspec recommend checking with the glass manufacturers and suppliers first to see what they can supply.
We will keep you posted as things unfold.
Building Control Update 183