Warm Roof System

What is a warm roof?

Warm roof construction is where rigid board insulation is placed over the roof deck and the waterproof membrane is laid over the insulation. This means that the insulation is on the outside of the building envelope and the roof structure and ceiling space are at a similar temperature to the building interior.

Introduction

The Nuratherm systems uses Enertherm PIR insulation, a rigid, high-performance board designed to deliver maximum thermal resistance with minimal thickness. It is widely used in warm roof systems throughout New Zealand, often specified in projects where both energy efficiency and aesthetics are paramount.

Enertherm PIR sits above the vapour barrier and beneath the waterproofing membrane, maintaining continuous insulation across the roof and eliminating thermal bridging. It’s compatible with Nuraply membranes and offers high compressive strength and long-term dimensional stability.

The ALU foil facer is conductive. This means that, in a first for New Zealand, all Nuratherm PIR installations are able to be installed ready for Electronic Leak Detection

Enertherm PIR has been used on hundreds of successful projects, supported by CodeMark certification and comprehensive technical guidance. It’s a smart choice for specifiers seeking performance, reliability, and compliance in warm roof construction.

Advantages and benefits

The advantages of warm roof construction:

Thermal bridging is largely eliminated as the insulation is continuous over the whole roof structure.

The need for roof space ventilation is eliminated or reduced. The ceiling space is on the warm side of the insulation. The dew point temperature (the temperature at which water vapour in the air condenses as water) is on the exterior side of the insulation, so condensation is unlikely to occur.

Warm roofs have significant benefits over cold roofs because:

energy efficiency is improved heating and ventilation costs are reduced.