Product Cost
The cost of spray foam insulation depends on the foam type, required thickness, target R-value, total area and site accessibility. It generally costs more upfront than conventional fibreglass or wool insulation but doesn’t need replacing for the life of the home. NZ Foam reviews the project plans and specifications before providing an accurate quote.
Spray foam can provide strong long-term value where airtightness, moisture control, limited cavity depth and lasting thermal performance are priorities. Its continuous application can reduce gaps and uncontrolled airflow while helping create more consistent indoor temperatures.
Product Efficacy
Closed-cell spray foam is denser and provides a higher R-value per millimetre. It also offers greater resistance to moisture movement and can add rigidity, making it well suited to containers, roofs, exterior walls and other exposed applications.
Open-cell spray foam is lighter and expands further, making it useful for filling irregular spaces and reducing sound transmission. It provides a lower R-value per millimetre and different moisture-control properties, so the correct product must be selected for the application.
NZ Foam utilises closed-cell spray foam in all applications.
NZ Foam’s specified closed-cell product provides approximately R1.1 per 25 mm of installed foam. Published examples include:
30 mm: approximately R1.3
50 mm: approximately R2.2
70 mm: approximately R3.1
90 mm: approximately R4.0
100 mm: approximately R4.4
The required thickness should be calculated from the construction R-value needed for the complete building element.
Yes. Spray foam expands into gaps, cracks and irregular junctions, helping create a continuous air-control layer. Reducing uncontrolled air leakage can limit draughts, heat loss and moisture movement through the building envelope. Purpose-designed ventilation must still be provided to maintain healthy indoor air quality.
Spray foam adheres directly to the surface onto which it is applied, so it is not expected to sag, slump or settle under normal service conditions. This helps prevent new gaps from developing and supports consistent thermal performance over the life of the installation.
About NZ Foam
NZ Foam is headquartered in Christchurch and provides spray foam insulation services nationwide. Its teams work across residential, commercial, container, agricultural, marine, civil and specialist projects throughout New Zealand.
NZ Foam provides professionally installed spray foam systems for projects throughout New Zealand. Its specified closed-cell product has CodeMark certification for relevant Building Code provisions and is installed by trained and approved applicators. Installations are also supported by a transferable 50-year limited lifetime product warranty.