HIA Industry Update – January 2020
In recent times, it has become common practice to install an electrical or other meter box without installing a steel lintel above it to support the brickwork above. It is assumed that due to the size of the meter box a lintel above is not warranted and this is somewhat supported by what is stated in the Building Code of Australia (BCA).
But is this acceptable and does this actually comply with the code?
National Construction Code Volume Two BCA 2019
To comply with the BCA you need to satisfy the Performance Requirements which are the mandatory requirements to be satisfied.
The relevant Performance Requirement in this situation is P2.1.1 Structural stability and resistance which states:
‘A building or structure, during construction and use, with appropriate degrees of reliability, must perform adequately under all reasonable expected design actions; and withstand extreme or frequently repeated design actions.
The actions to be considered to meet the above requirements must take into consideration (but not limited to):
- Permanent actions (dead loads); and
- Wind action; and
- Rainwater action; and
- Differential movement; and
- Time dependent effects (including creep and shrinkage); and
- Thermal effects.’
One of the ways to meet the above performance requirements is through one of the Deemed to Satisfy Solution pathways.
- Using the Australian Construction Manual (ACM) Australian Standard AS 4773.2 Masonry in small buildings Part : Construction, or
- The Acceptable Construction Practice (ACP) method prescribed in the Code.
The Australian Standard clause 8.1 states ‘except in the case of arches, brickwork over openings shall be supported on a lintel…’ the clause goes on to specify different types of lintels.
The BCA Part 220.127.116.11 deals with openings in masonry veneer and states simply that openings in masonry veneer must be spanned by steel lintels’.
The provision then goes on to state that ‘Openings in masonry veneer not more than 500mm wide need not be provided with a steel lintel provided the opening is adequately supported’. (Note: this clause only applies if the house or structure meets the design requirements under clauses 18.104.22.168 and 22.214.171.124 (for example the site soil classification can only be A, S or M))
But what does ‘adequately supported’ actually mean?
When installing a standard commercially available meter-box, which is typically 470mm to 490mm wide, to determine if a meter-box will adequately support the brickwork above without a lintel, you would need to ask the manufacturer if their meter-box has been designed for this purpose.
This may also be information they provide in their product data sheets if they provide one.
The manufacturer would generally need to have the product tested to determine that it will satisfy the BCA requirements in this case but if they cannot supply that information a steel lintel should be installed.
This may be a simple and fairly inexpensive way to ensure you are complying with the BCA and there will be no issues with certifiers, building surveyors or State or Territory building authorities.
For more information, call our HIA Building and Planning Services Advisers on 1300 650 620.
HIA Executive Director – Hunter