The lowest carbon building is often the one that is not built yet. Recycling, repurposing or renewing existing buildings is an excellent way to get more use out of the embodied carbon of the existing structure, lower the energy used by the inhabitants of the property and prevent expending more carbon on a rebuild.

As a Toitu Carbonzero certified company, Nuralite is committed to helping New Zealand build better. They aim to be involved in projects where smart, innovative design is used and have found roof renewals becoming increasingly popular.

Some building elements last longer than others. Foundations are expected to outlast the interior fit out, for example. Similarly, some roof membranes will need replacement sooner than others.

Nuralite maintains that a long-lasting, quality product is one of the best ways to add sustainable value to any specification choice. Overlaying existing membranes is a great way to breathe life back into a roof and extend a building’s useability.

The robust nature of the Nuraply 3PM system means it can be easily overlaid with two renewals on top of the original system. Therefore the roof can be kept in service for up to 90 years, which is considerably longer than most exterior waterproofing options.

Consider anticipating future membrane renewals when detailing the original roof, including junctions to other building elements. The 90–year model relates specifically to the Nuraply 3PM system, following the below schedule:

• 0-30 years: The original two-layer Nuraply 3PM system is installed.
• 30-60 years: The first renewal is installed over top of the original.
• 60-90 years: A second renewal is directly overlaid.

With a collective effort in the building industry to act with sustainability in mind, Nuralite has seen a lot of projects where roof renewals are the first choice. Recently one of their applicators MPM worked with Savoury Construction to re-roof their head office in Mt Wellington. The project involved replacing an old, damaged membrane and installing a new waterproofing membrane on top.

MPM first laid down a plywood substrate over the existing membrane to ensure an adequate roof fall would be in place for the Nuraply 3PM system. The system can be installed with a fall of 1:80 on ply, which is part of its CodeMark certification and provides a 1 degree guarantee.

As this project occurred in winter, a shrink wrap was used to protect the structure from the weather and meant the team could work through despite the conditions. Once the plywood was installed the two layer Nuraply 3PM system was laid and the project could be completed in a few weeks.

Re-roofing the structure saved both time and money for all involved, as well as enabling the office to be fully operational throughout the process. A renewal is a great option for old roofs, you don’t need to completely start from scratch to create a watertight roof.

Focusing on avoiding carbon emissions is the future of the building industry and we will be seeing a lot more roof renewals in the pipeline.

To learn more, view Nuralite's webinar on Upgrading Existing Roofs: