Page 8 - Build 151

Letters
Structural adequacy DEAR BUILD,
I would like to point out an error in Build 150 Fire terms and testing (pages 28–29).
The Fire Resistance Rating (FRR) is, as stated, made up of three numbers x/x/x but the rst number is not stability, as quoted in your article. It is structural adequacy. The latest amendments to the Building Code clause C Protection from fire revised the rst number de nition from stability to structural adequacy.
DENNIS FISHER : BLENHEIM
Several of our readers noted the incorrect use of the word ‘stability’ in the article. We must apologise as it should indeed have been ‘structural adequacy’. This refers to the ability of the building element to sustain a vertical load during a re resistance test. The
load is as required by NZBC clause B1.
The term stability is used in other contexts in the Acceptable Solutions to clause C. Two
types of stability are referred to:
• Vertical stability, which is the ability of a primary element to resist a vertical load and is related to structural adequacy.
• Horizontal stability, which refers to the ability to resist a horizontal load (and ther- mal actions) as specified in NZBC B1/VM1.
Stability ensures that elements having a Fire Resistance Rating (FRR) are supported so that the element continues to perform its intended function for the required duration.
Comment
WRITE TO US: Build welcomes letters but reserves the right to select which to publish and to edit letters to t the space available. Send your letters to the Build Editor, Freepost BRANZ, Private Bag 50 908, Porirua City or email [email protected].
6 — December 2015/January 2016 — Build 151