In designing a surface water drainage solution, you must consider the performance of the design in service. This design must allow for stormwater to be disposed of without causing damage, nuisance, flooding, erosion, or water entry into buildings.

An area often queried is the management of stormwater passing through a membrane surface, typically a downpipe penetrating a membrane deck or canopy.

New H1 requirements have led to changes in the location of fixtures on the building line. This changes the way threshold drains and perimeter channels interact with insulated slabs and glazing suites — a challenge which can be simplified with the use of system-based threshold solutions.

Tiled showers in second storey ensuites and multi-unit developments often create design challenges and durability risks to designers and homeowners alike. How can these areas be more durable and remove the risk of leaks or failures in the selected system?

Detailing of the rainwater outlet penetration — from flange preparation to overflow provision — plays a central role in protecting the building envelope from moisture ingress.

Meeting the requirements of E2 ch 7.4 will ensure that your design offers a compliant level threshold solution, negating the need for any specific design. Avoiding alternative solution designs will assist in a smoother consenting process and reduce RFI responses.

Waterproof membranes are provided under porous surfaces in wet areas or splash zones to prevent subsurface moisture from escaping the area. This moisture must be carefully managed and given the opportunity to evacuate the environment below the finished surface by way of a leak control flange.

During the design stage it is important to specify a drainage system that caters to the activity of the facility, allows for the desired layout and delivers reliable performance.

When detailing channel drainage be it in a domestic driveway or in a public thoroughfare, load ratings will be important along with other aspects such as slip resistance and hydraulic performance.

Understanding the applicable NZBC clauses for a durable, functional and compliant drainage system at the garage door.