Fit for Purpose – Evidence Report
One of the services provided by CJK is the assessment of construction components as being fit-for-purpose.
The report produced, could become a document in accordance with National Construction Code (NCC) 2022 Clause A5G1 which relates to the quality of work and materials needed to construct a building to meet NCC requirements.
This means that –
- all people involved with construction must work skillfully in accordance with good trade practice; and
- all materials must be of a quality to fulfil their function/s within the building.
Evidence to support that the use of a material, product, form of construction or design meets a Performance Requirement or a Deemed-to-Satisfy Provision may be in the form of any one, or any combination of the following:
- A current CodeMark Australia or CodeMark Certificate of Conformity.
- A current Certificate of Accreditation.
- A current certificate issued by a certification body stating that the properties and performance of a material, product, form of construction or design fulfil specific requirements of the BCA.
- A report issued by an Accredited Testing Laboratory.
- A certificate or report from a professional engineer or other appropriately qualified person.
- Another form of documentary evidence, such as but not limited to a Product Technical Statement.
An example of this is a recently conducted External Cladding Junction Assessment.
In construction, control joints are used to relieve stress induced to building components by small movements caused by shrinkage, expansion, moisture and the like. Control joints are designed by the building designer to strategically control cracking.
In relation to fire safety, control joints are only referred to within the respective NCC provisions when dealing with joints within fire-resisting construction. The fire safety requirements are limited to the need of providing appropriate fire stopping to any openings that could compromise the fire-resisting performance of the respective building element.
There are no specific requirements for providing control joints within the external fabric of buildings for fire-safety purposes, unless the joint formed part of a tested system.
A party wall is a wall shared by two adjoining properties. The fire safety mechanism applied around party walls is that in the event of a fire within one of the adjoining units, the internal linings of the fire-affected unit are allowed to dislodge, exposing the fire resisting core of the wall system, which then provides fire separation between the fire-affected and non fire-affected unit.
In a fire situation, having a control joint aligned with the Party Wall increases the chances of the external cladding to crack and separate at the separating wall. This is likely to result in less damage to the external lining of the neighbouring unit. That is, in case of a partial collapse of the separating wall, none or very little external cladding on the non-fire-affected unit is considered to get affected.
Having a control joint offset from the separating Party Wall is likely to result in cracking at the closest control joint, which could result in some cladding damage or dislodgement on the non-fire-affected unit.
The report goes on to propose a design that demonstrates the construction detail meets the fire safety requirements of the NCC and is fit-for-purpose.