Waihi Beach green roof
Jul 2024 . Written by Clare Thorne, Greenroofs
Greenroofs Ltd installed an 80m² green roof at Waihi Beach in October 2022 above a boat shed/garage.
The growing medium was 150mm in depth over a Nuralite water proofing membrane. Planting was a mixture of NZ native and exotic grasses, tussocks, ground-cover & specimen plants with a 250mm wide riverstone pebble margin and a simple battery operated dripline irrigation system to aid establishment. The installation took two men three days and the package includes a maintenance visit every 3 months for the first year.
On 29th May 2023 a weather ‘bomb’ hit Waihi Beach and 60mm of rain fell within an hour and over 100mm fell in a 5 hour period causing significant flash flooding.
The clients and the architect were impressed by the green roof’s performance as the water from the excessive rainfall was observed gently running off the roof and through the down-pipes for the next 5 days. They gave the roof and the services from Greenroofs Ltd a rating of 10 out of 10!
The architect - John Monro of DRS Architecture in Paeroa:
Where did the initial idea of a green roof come from?
Early discussions with the owners raised the idea of something different compared to a traditional pitched roof and once the infrastructure issues opened with stormwater discharge only to the road kerb line, the decision was answered when reading that green roofs retain 80 % water on the roof and then slowly discharge.
What is the main purpose of the green roof?
The resource consent for the project identified the inclusion of the green roof. The council fully supported it, and approval was granted.
