Making room for thicker insulation
‘The new insulation regs have created this real issue of compressing the insulation blanket hard up against the building paper around the eaves,’ says Darryl. ‘But you still need to maintain an air gap between it and the roof underlay. Jaden brought this to my attention – thank goodness he did. All builders need to know about it.’
Jaden de Bruin, Masons’ Specification and Business Development Manager for Auckland and Northland, explains: ‘With condensation in roof cavities being reported even in new homes, Darryl was very interested in using these products to help keep his roof insulation and roof space dry.’
Maintaining airflow through the roof cavity
Masons’ roofing components work together to create a breathable roof cavity. The Insul-Baffle allows insulation to be installed without being compressed at the eaves, maintaining a 25mm air gap between the insulation and the roof underlay.
‘If you don’t have the Insul-Baffle, the insulation presses the building paper onto the roofing iron,’ says Darryl, ‘which leads to poor airflow, condensation and dampness.’
Jaden adds: ‘Then you have the ventilated roof battens, which work with the baffle. The holes in the battens allow air to circulate, and when you install a ridge vent as well, that warm, moisture-laden air escapes.’
The third product used in this build is Masons’ high-performance VHP Value Roof Underlay – a tough, highly breathable synthetic underlay that’s self-supporting and easy to work with.
Effective and easy to install
‘The Insul-Baffle comes off the roll straight over the rafters,’ says Darryl. ‘It’s a corrugated, pliable, clear plastic, so the corrugations allow it to sit on the trusses for support. The ventilated roof battens are tacked on top of the purlins, which lifts the roofing and building paper to keep ventilation moving through. It’s an effective and elegant preventative measure.’
Darryl says he’s glad he gave it a go. ‘The increase in R values and H1 regulations has forced a change, and we need to adapt. Jaden’s across all those changes and keeps me up to date. Building inspectors will be all over this.’
