We get down and dirty


There are several types of underfloor insulation you can choose for your home. It's important to choose the right insulation for your needs.

Talk to the crew at Xtreme Rebuild today and we can advise you on the insulation you need.


Earthwool glasswool: Quilted underfloor batt, R-1.5 provides high thermal performance to create a comfortable environment in your home. Earthwool glasswool underfloor batt insulation is completely wrapped in film which acts as a wind-wash barrier to provide protection from air movement under the floor. Adding to the already easy to handle and install qualities of Earthwool glasswool, the insulation is completely wrapped in film and can be stapled in place. It is made using up to 80% recycled glass and with ECOSE Technology, a sustainable, bio-based binder that contains no added formaldehyde. As well as providing a great result, this product is extremely durable and comes with a 50-year warranty, so will stand the test of time.

·        Wind wash barrier for high thermal performance

·        No added formaldehyde


Expol is a pre-cut polystyrene foam board that fits easily between existing floor joists. Each Expol panel is shaped to create an air gap which provides added insulation and minimises mould growth. Expol is non-allergenic and contains no CFCs. It contains a flame retardant and its thermal properties stay constant over time.

Expol comes in panels 1.2 metres long and 55mm thick, with a variety of widths to fit standard New Zealand joist spacing without modification. Panels can be removed as necessary to access electrical wiring. Most installs fit snugly between joists and support themselves, but for unusual spaces we use non-corrosive nylon fixings and stainless steel nails.

Expol is fully compliant with the New Zealand Building Code, and comes with a 50 year warranty. The diagram below shows an example of how Expol might be laid under your floors.    


Autex’s GreenStuf® thermal and acoustic home insulation products are made from durable, environmentally-friendly 100% polyester. Highly resistant to fire and moisture damage, they’re designed to keep your home warm, quiet, healthy and energy-efficient for a lifetime. GreenStuf products can easily be torn to size by hand, making them simple to install for home DIY enthusiasts.

GreenStuf Underfloor is designed to provide thermal insulation under exposed joist floors of new and existing timber-framed buildings. GreenStuf Underfloor reduces heat loss through floors and assists in reducing drafts through joins in the floor structure. It comes as rolls pre-cut to fit standard exposed timber joist floors and is easily installed by stapling into place between the joists.