Flashings

What is a flashing?

A Flashing is the name of a purpose made building component that is intended to capture and drain or deflect water back outside of the cladding system.

Although flashings are one of the smaller building components, they are vitally important making them one of the best investments in your entire building!

Where are flashings used?

Flashings typically occur at junctions where building materials join. Some flashings are very obvious and they may be a defining feature of a building - such as the capping along the ridge of a roof, or a parapet.

Other flashings may be less noticeable, being mostly hidden within the construction, but they are just as important!

Getting it right

There are numerous parts of a building that may require flashing. Because of the unique demands of each situation, flashings should be specifically designed for the particular circumstances of each location.

The principle of flashing is easy to understand, but the designing, manufacturing and installing a particular flashing may not be so simple.

The New Zealand Building Code has acceptable flashing designs and material specifications for most situations. Refer to NZBC Clause E2/AS1 (4th edition) section 4.0 (and other references within that document). The flashings should be chosen and specified by the Licensed Building Practitioner building designer who is assigned that responsibility by law.

Supply Options

Everything in one package

WANZ Window and Door Manufacturers provide flashings that are designed to work with the windows and door you select, and importantly are colour matched and delivered to site as one package. You simply order the windows, doors and the installation materials from the WANZ Window Manufacturer at the same time so that everything is made to fit together. 

Most WANZ window manufacturers will also install and guarantee the finished job – either directly to you, or to your builder.

To find a Window and Door Supplier complete with flashings and installation, click here

Flashings as a building material

WANZ flashing manufacturers can also provide “specials” which are made to order and provide the ultimate in design flexibility. Flashing manufacturers also routinely manufacture the standard NZBC designs.

To find a flashing manufacturer, click here

Alternative Solutions

The New Zealand Building Code encourages innovation and there are several patented “Alternative Solutions” available from WANZ members. These are proprietary products developed and tested by the member concerned. Any new complete window installation flashing system will need to be verified with IANZ accredited laboratory tests to NZBC E2/VM1 for cavity claddings or AS 4284 for direct fix systems.


To examine these options, and their respective services and performance claims, click the link below:

To find Suppliers of Alternative Solutions, click here