What is MAXRaft®?

A thermally broken slab that is also fully insulated; the only one of its kind on the market. It forms the floor of your home, only needing minimal bracing. It is custom cut and supplied to site where a friendly and knowledgable team of professionals will install the MAXRaft® component, leaving your builder to install all of the reinforcing material and concrete.  


Who provides the Engineering design?

As a part of our package, MAXRaft has it's own fully qualified engineers who can provide a site specific engineering design. Alternatively if you would like to use your own engineer then we can work in with you to ensure a smooth design process. 


Why should I choose MAXRaft®

You can change your windows, you can replace your carpet, you can buy a new kitchen...

You can't change your foundation.

MAXRaft® is a great choice for any home.  MAXRaft® acts as the thermostat for your home which means the temperature does't' fluctuate as much as other floors. This constant temperature reduces the susceptibility of your home to mould growth and assists in providing a warm and healthy living environment.  


What kind of technical support does MAXRaft® provide?

We supply a full onsite guide to builders and owners, architects and engineers, which supports the site specific PS1.  There is also a technician who can be reached by dialing 0800 MAXRAFT.


How is MAXRaft installed?

MAXRaft® is available in two ways; either as supply and installation of the MAXRaft insulation only OR as a fully installed slab system by MAXRaft's installers. MAXRaft® has a comprehensive Onsite Guide and with guidance from the MAXRaft® team any full trained builder can install a MAXRaft system.   


How do I coat the outside of MAXRaft®?

There are a few different options for coating the outside edge of MAXRaft® from a Hard Edge to a Plaster finish. Please see our Protecting MAXRaft® page.


What sets MAXRaft® apart from similar methods?

Warmer, healthier and more energy efficient homes.

Increased thermal efficiency & higher R-values., Less time on site, Site specific engineering, Reliable proven construction details, 


Can MAXRaft® be installed anywhere?

Yes.  MAXRaft® is available nationwide and can be custom engineered to work on any site, in any conditions.  MAXRaft has systems that are suitable for good and soft ground, including TC2 sites in Christchurch. 


How do I go about ordering a MAXRaft® floor?

Simply email a full set of your plans along with a Geotech report (if applicable) to info@maxraft.co.nz.  We can produce a quote for you within 2-3 days.


How environmentally friendly is MAXRaft®?

Known for its highly efficient insulating properties, Expanded Polystyrene (EPS) has long been a leading choice in the industry for energy efficient homes. Plastics New Zealand has designated EPS as compatible with the environment as a result of its insulation ability. The waste produced in the MAXRaft® production process is recycled and eventually turned into new EPS insulation.


How quickly can I get a MAXRaft® floor?

Once the underslab drains are completed and the site is level and compacted, the site will be ready for concrete within two days.  


If we already have consent for a standard slab can we change to a  MAXRaft® floor?

Yes, we will supply an engineered foundation package and you will have to fill out a variation to your building consent.


How does MAXRaft® perform in an earthquake?

Prior to the Christchurch Earthquake we had installed multiple MAXRafts.  They performed well and are all still all being occupied today.  One of the floors was in the epicentre of the earthquake in Salisbury Road, most of the building around it had to be demolished


Can MAXRaft® be used in conjunction with underfloor heating?

Because the MAXRaft® is fully insulated underfloor heating works very well, potentially improving the systems efficiency by 30 – 40%. A client of our has calculated the cost of heating his home at 60.8c/m2 per month.


What is the R Value of a MAXRaft® 

Because all floors are different the R value varies but a typical MAXRaft® foundation has an R-value of approximately R4.5. Try our calculator here (opens in MS Excel).


How does MAXRaft® perform with a polished concrete floor?

Excellently. Because the MAXRaft® isn’t tied to ground, the concrete will shrink when curing resulting in a stronger,  crack resistant floor.  Because of our experience with polished floors we are able to offer some advice when considering a polished finish.  


Can I use MAXRaft® with 90mm frames?

Yes. MAXRaft is suitable with 90mm frames or wider frames.  When used with 90mm frames MAXRaft will recommend specific bolt fixings to ensure requirements are met. This is not necessary if the frames are 140mm +.


Question not answered? No panic!  Simply call us on 0800 629 7238 or 03 409 2111 to speak with one of the team. 

About Us

Our focus is on providing New Zealander's with warm, cost effective and healthy living environments. Founded in Queenstown MAXRaft® is now available throughout New Zealand. As well as offering a superior thermal performance, MAXRaft® also saves time onsite and comes fully installed by our team of installers.


USEFUL downloads (click to download)

MAXRaft Construction Specifications

MAXRaft Onsite Guide



EPS & The Environment    From www.plastics.org.nz


Environmentally Friendly

The excellent properties of EPS, providing economic and high performance products, are further enhanced by its environmentally friendly characteristics. By most methods of measurement, EPS has a positive contribution to the environment at every stage of its life cycle.

From raw material production, to processing into useable products, to the daily use of those products, to disposal or recycling EPS uses less energy, saves more energy, or has fewer emissions and creates less environmental impact on disposal than most competitive materials.

Objective, scientific studies have demonstrated the benefits to the environment of using EPS in preference to other materials.

The manufacture of disposable drinking cups demonstrates dramatically the resource and energy efficiency of EPS. Compared with EPS cups of the same size, paper cups consume:

• 170 times as much process water
• 30 per cent more cooling water
• 15 times more chemicals
• 13 times more electricity
• 6 times as much steam

Reduced Effects on Atmosphere

In terms of global warming, EPS plays a positive role in reducing carbon dioxide emissions. Domestic and industrial consumption of fossil fuels for heating is recognised as a significant contributor to the global output of carbon dioxide. It has been estimated that the effective application of EPS insulation could cut carbon dioxide emissions by up to 50%.

As the insulation performance of EPS does not deteriorate during its lifetime, this reduction in emissions lasts the full lifetime of a building. The manufacture of EPS raw material and processing into useable products does not require the use of CFCs or HCFCs.

Minimises Waste on Disposal

EPS accounts for less than a tenth of one percent of the weight of municipal waste. The foam scrap improves the aeration of landfills and thus contributes to a faster degradation of the organic substances.

EPS products do not degrade into harmful substances, are not water soluble and do not give off any water soluble substances which could lead to contamination of ground water.

Efficient use of Resources

The most effective way to reliably assess the overall environmental impact of materials is by 'Life Cycle Analysis'. This internationally accepted method evaluates all impacts, including raw material processing, product manufacture, energy consumption in processing, manufacture and use, and effects on the environment of disposal and recycling. There are many examples which illustrate the benefits of using EPS.

EPS is produced from oil and as it comprises approximately 98% air, it consumes only a small fraction of one percent of oil use. On a volume basis, EPS production uses between one third and one half of the energy required for an equal volume of cardboard. Many homes, coolstores, commercial and industrial buildings use EPS for insulation to save valuable energy.

Home insulation can reduce heat losses by up to 70%. For each kilogram of oil used in the manufacture of EPS insulation, savings of up to 200 kilograms of heating fuel can be made over the average life of a house.



MAXRaft recycles up to 98%

EPS can be readily recycled in several ways. Within the processing plant, internal waste can be ground and mixed in various proportions with virgin material in the production of EPS blocks and mouldings.

Recycled material is used for the manufacture of drainage board.

Recycled EPS can also be mixed with plaster to provide insulated coatings, and concrete to produce light weight blocks.

When melted, EPS becomes solid polystyrene and shrinks to its original volume. Once solidified it is reground into solid granules and used in the production of simple polystyrene products such as pens, coathangers and other plastic goods.