When new joinery units are designed and certified to NZS4211, a ‘blueprint’ unit is constructed in the specifically for the laboratory test procedure. This doesn’t, however, allow for the inherent variability in a volume manufacturing process. On-site water testing of joinery – windows, and doors – is a way of ensuring the weathertightness of newly installed joinery on-site and mitigating the risks of manufacturing defects. On-site testing will also check the connection between the joinery unit and the surrounding cladding, part of a weathertight quality assurance process.
In some cases, joinery is imported to New Zealand that hasn’t been tested to NZ standards and is placed into buildings without approval from the building consent authority (council). In this situation it can be possible to certify the windows are weathertight to the satisfaction of council via on site spray-rig testing. The relevant standards in New Zealand are AS NZS 4284:2008 Testing of building facades and NZS 4211:2008 Specification for performance of windows.
The test methods applicable to on-site joinery testing are ASTM E1105 -15 Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference and AAMA 502.12 – Voluntary specification field testing of new installed fenestration products.
If joinery units have been installed in the building for more than 6 months, an alternative test method is recommended, AAMA 511.08 Voluntary Guideline for Forensic Water Penetration Testing of Fenestration Products.
This test procedure also references ASTM E1105-15 and AAMA 502. An AAMA 511.08 test includes a forensic investigation and reporting procedure applicable to determining sources of leaks and is related to the actual wind pressures experienced by the building during leak events, extracted from climate data, rather than theoretical design related test pressures required for new joinery testing.
Our test method varies from the ASTM and AAMA methods, in that we use our Minneapolis blower door to create a pressure differential across the sample window or door. The above test methods perscribe an evacuated test chamber to be built around the joinery unit to be tested, a lengthy and expensive procedure.
Our blower door can be quickly set up in a doorway and allows several windows and doors of different sizes to be tested concurrently, or consecutively, without moving the blower door equipment. Also the tester is effectively inside the test chamber, making the visual inspection and diagnosis of leaks much easier.
Our experience of forensic investigations of existing buildings shows that existing joinery units in buildings of around 10 years old rarely pass spray rig testing and that the air seals between the joinery units and structure are often missing or incomplete. This means that joinery testing can be a valuable addition to building defect claims.
The evidence of the last fifteen to twenty years of the NZ construction industry’s mistakes leads us to one fundamental conclusion: It is better to try and get it right first time rather than re-visit the mistakes later at considerable cost to building owners, tenants, designers, contractors, sub-contractors, councils, government, insurers and lenders.