Underfloor insulation

As a Government approved EECA Energywise Warm Up New Zealand: Heat Smart service provider, we installed retrofit insulation into hundreds of underfloors all over the South Island from our bases in Christchurch, Greymouth and Queenstown.

With a decade's experience and an extremely high quality rating from EECA, we guarantee compliance with the Residential Tenancies Act and the Healthy Homes Standards.

Remember, we are 100% independent of any brands or exclusivity agreements and we will only install the right product for your specific home. For most houses we recommend a polyester staple-in blanket like Premier, Mammoth, Terra Lana and Autex Greenstuf.

We also install Pink Batts snugfloor, Bradford Gold Optimo, Knauf Earthwool and others where we consider them a better choice.

See the photo gallery below for some examples of typical underfloor installations.

If you would like an in-home insulation assessment and quote, call us on 0800 420 845.

Underfloor insulation - Retrofit R1.6 insulation and vapour barrier

As well as Technobond R1.6 polyester blanket (its the purple stuff), this house had mould and moisture on the ground. NZS4246:2016 specifies that a 250 micron polythene vapour barrier should be installed if this cannot be improved through drainage or ventilation.

Underfloor insulation - Retrofit R1.6 blanket

Technobond R1.6 underfloor insulation installed here in a very typical property with a nice dry sub-floor

Underfloor insulation - Retrofit R1.6 blanket

Technobond R1.6 in all of it's purple glory. The keen-eyed observer will point out the gap to the left of the picture. This is actually a 100mm clearance for pipes that penetrate the floor, as required by NZS4246:2016. One of many requirements that can be overlooked by an untrained eye

Underfloor insulation - Retrofit R1.6 blanket

This sub-floor is clearly dry and well ventilated as indicated by the piles of dust left by the installer's back as they crawled along. A vapour barrier is not required in this case.

Underfloor insulation - Retrofit R1.6 blanket

Care should be taken to minimise the heat loss around pipes that is a result of NZS4246:2016 clearance requirements. Here you can see the 100mm gap required is as big as neccessary but as small as practical.

Underfloor insulation - Retrofit R1.8 blanket

This house received upgraded Mammoth R1.8 polyester insulation which is 115mm thick nominal. Stapled to joists after friction fitting, this insulation is still in place after a recent flood

Underfloor insulation - Retrofit R1.5 Blanket

This Mammoth polyester insulation is R1.5 and 100mm thick nominal. Compared to the previous image you can tell the insulation is thinner however still exceeds the minimum requirements of the Residential Tenancies Act

Underfloor Insulation - Retrofit R1.5 Blanket

This small area of Mammoth R1.5 polyester blanket insulation has 8 inch joists so the insulation doesn't appear to be as thick, but it is actually 100mm nominal. Typical of an extended bach this was the only accessible area of the underfloor