NCC 2016 Volume Two
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Part 2.2 Damp and Weatherproofing (Verification Methods)
Compliance with for the weatherproofing of an external wall that—
has a risk score of 20 or less, when the sum of all risk factor scores are determined in accordance with Table V2.2.1a; and
is not subjected to an ultimate limit state wind pressure of more than 2.5 kPa; and
includes only windows that comply with AS 2047,
is verified when a prototype passes the procedure described below:
The test specimen is in accordance with the requirements of (b).
The test procedure is in accordance with the requirements of (c).
The test specimen does not fail the criteria in (d).
The test is recorded in accordance with the requirements of (e).
Table V2.2.1a – RISK FACTORS AND SCORES
Risk factor | Category | Risk severity | Score |
---|---|---|---|
Wind region | Region A (AS/NZS 1170.2) | Low to medium | 0 |
Region B (AS/NZS 1170.2) | |||
Region C (AS/NZS 1170.2) | High | 1 | |
Region D (AS/NZS 1170.2) | Very high | 2 | |
Number of storeys | One storey | Low | 0 |
Two storeys in part | Medium | 1 | |
Two storeys | High | 2 | |
More than two storeys | Very high | 4 | |
Roof/wall junctions | Roof-to-wall junctions fully protected | Low | 0 |
Roof-to-wall junctions partially exposed | Medium | 1 | |
Roof-to-wall junctions fully exposed | High | 3 | |
Roof elements finishing within the boundaries formed by the external walls | Very high | 5 | |
Eaves width | Greater than 600 mm for single storey | Low | 0 |
451-600 mm for single storey; or greater than 600 mm for two storey | Medium | 1 | |
101-450 mm for single storey; or 451-600 mm for two storey; or greater than 600 mm for above two storey | High | 2 | |
0-100 mm for single storey; or 0-450 mm for two storey; or less than 600 mm for above two storey | Very high | 5 | |
Envelope complexity | Simple shape with single cladding type | Low | 0 |
Complex shape with no more than two cladding types | Medium | 1 | |
Complex shape with more than two cladding types | High | 3 | |
As for high risk but with fully exposed roof-to-wall junctions | Very high | 6 | |
Decks, porches and balconies | None; or timber slat deck or porch at ground level | Low | 0 |
Fully covered in plan view by roof; or timber slat deck attached at first or second floor level | Medium | 2 | |
Balcony exposed in plan view at first floor level; or balcony cantilevered at first floor level | High | 4 | |
Balcony exposed in plan view at second floor level or above; or balcony cantilevered at second floor level or above | Very high | 6 | |
Notes:
|
Test specimen
The test specimen must incorporate—
representative samples of openings and joints, including—
vertical and horizontal control joints; and
wall junctions; and
windows or doors; and
electrical boxes; and
balcony drainage and parapet flashings; and
footer and header termination systems; and
for a cavity wall—
a transparent material for a proportion of the internal wall lining (to provide an unobstructed view of the external wall cladding) with sufficient structural capability and similar air tightness to resist the applied wind pressures; and
a 15 mm diameter hole in the internal wall lining below a window.
Test procedure
The test procedure for a direct fix cladding wall or unique wall must be as follows:
Apply 100% positive and negative serviceability wind pressures to the external face of the test specimen for a period of not less than 1 minute each.
Apply static pressure of either 300 Pa or 30% serviceability wind pressure, whichever is higher, in accordance with the water penetration test procedure at clause 8.5.2 of AS/NZS 4284.
Apply cyclic pressure in accordance with—
the three stages of Table V2.2.1b; and
the water penetration test procedure at clause 8.6.2 of AS/NZS 4284.
Table V2.2.1b
Stage number | Serviceability wind pressure |
---|---|
1 | 15% to 30% |
2 | 20% to 40% |
3 | 30% to 60% |
The test procedure for a cavity wall must be as follows:
Apply 100% positive and negative serviceability wind pressures to the external face of the test specimen for a period of not less than 1 minute each.
Apply static pressure of either 300 Pa or 30% serviceability wind pressure, whichever is higher, in accordance with the water penetration test procedure at clause 8.5.2 of AS/NZS 4284.
Apply cyclic pressure in accordance with—
stage 3 of Table V2.2.1b; and
the water penetration test procedure at clause 8.6.2 of AS/NZS 4284.
To simulate the failure of the primary weather-defence or sealing, the following procedure must be applied to the test specimen:
Insert 6 mm diameter holes through the external face of the cavity wall in all places specified below:
Wall/window or wall/door junctions at ¾ height.
Immediately above the head flashing.
Through external sealing of the horizontal and vertical joints.
Within 30 minutes of the completion of (bb), remove the internal lining of the cavity wall and check for compliance with (d).
With the internal lining removed, apply a final static pressure test at 50 Pa for a period of 15 minutes.
Compliance
A direct fix cladding wall and unique wall are verified for compliance with if there is no presence of water on the inside surface of the facade.
A cavity wall is verified for compliance with if there is no presence of water on the removed surface of the cavity, except that during the simulation of the failure of the primary weather-defence or sealing, water may—
transfer to the removed surface of the cavity due to the introduced defects (6 mm holes); and
contact, but not pool on, battens and other cavity surfaces.
Test report
The test report must include the following information:
Name and address of the person supervising the test.
Test report number.
Date of the test.
Cladding manufacturer's name and address.
Construction details of the test specimen, including a description, and drawings and details of the components, showing modifications, if any.
Test sequence with the pressures used in all tests.
For each of the static and cyclic pressure tests, full details of all leakages, including position, extent and timing.
Verification MethodV2.2.1 contains the same test procedures, compliance criteria and reporting of test results that are contained in Verification Method FV1, Volume One of the BCA. Consequently, the Guide to Volume One of the BCA contains detailed and supportive explanatory information that is also relevant to V2.2.1.