Green Dog Insulation Christchurch, Underfloor Insulation Installers and Ground Vapour Barrier Supply and install

Underfloor Ground Vapour Insulation Suppliers Installers Christchurch

More than 10% of the heat from your home can be lost through the floor so take the first step in insulating your underfloor today.

Underfloor insulation can reduce draughts as well as dampness as it can limit moisture from rising into the house from a wet or damp crawl space below. Limiting rising damp will create a warmer, drier room.

Contact us today to see what insulation subsidies and other funding options are available in your area.




Some Forms Of Insulation Don’t Cope Well

In Damp Conditions

Some forms of insulation don’t cope well with the damp conditions under your home and can sag after a period of time becoming less effective.

Our underfloor insulation installers are experts at crawling around under floors installing insulation quickly and safely to make your home warmer without fuss.

We can also let you know whether your home also needs a moisture barrier underfloor to avoid excess damp and where necessary can safely remove foil insulation that has lost it’s effectiveness by being torn, tarnished, corroded or dusty before installing your insulation underfloor.


  • Independent Advise 
  • Unbiased information 
  • Different Options to Suit budget
  • Professionally Installed 
  • Trusted 30-year-old company
  • Family Owned 
  • Solution For every type of property 
  • Fire Resistant 
  • Vermin Resistant 
  • Manufactures Guarantee
  • Price Quoted Is Price Paid 
  • FREE Home Insulation Survey

Coldest Place in New Zealand Thinks Of

Having The Correct Insulation Fitted.

Despite rivalry between Ophir and Ranfurly regarding New Zealand’s coldest town, Knauf Insulation chose the Central Otago settlement of Ophir when they decided to insulate the homes of a resilient community.

Knauf has completed a 12-month project to insulate every single home and most commercial buildings in Ophir from the pub to the church, warming up the lives of the 50 residents of the small town and the thousands of rail trail visitors that pass through every year.

In 1995, Ophir, two hours outside of Dunedin, recorded New Zealand’s coldest temperature of -21.6°C. Residents remember livestock freezing to the ground and prising frozen hens from their perches.

“We would have to cart buckets of water to the toilet to be able to flush because all of the pipes were frozen,” recalls Jack Allen, an Ophir local.

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The Pros and Cons Of The Different types of Underfloor Insulation

Polyester materials underfloor insulation sections:

Higher density sections that are easily squeezed in between joists and are self-supporting without staples or straps. Polyester insulation is moisture resistant.

Polyester Insulation Blanket

Can be stapled snugly into position by professional installers. Stapling underfloor where there are live wires can be dangerous for DIY installers.

Fibreglass Underfloor Insulation

This material is low density and is used extensively in ceilings and floors but underfloor can be affected by the damp conditions.

Foil Underfloor Insulation

Was used extensively years ago for reducing radiant heat loss. Its effectiveness is lost when it is tarnished or corroded, collects dust or condensation, gets ripped or damaged. Due to the risk of electrocution in working with a conductive material around electrical wiring – extreme care must be taken with the installation.

Polystyrene Underfloor Sheets

These are rigid sections that have been used extensively in the past. The polystyrene must be isolated from wiring for safety as it can be affected by the polystyrene material. Some forms claim to be self-supporting but require tacks or fittings to hold them in place.

Ground Moisture Vapour Barriers Install And Supply

About 75% of existing houses with suspended floors don’t have enough ventilation when compared to the Building Code.  So that 25kg of moisture/day is not going to be dissipated through ventilation; it will rise up into the house.


While Installing underfloor insulation is vital for improving indoor temperatures, a vapour barrier is a great (and cheap) step to control moisture.   Reducing sources of moisture coming into the house is important because not only does moisture create the conditions for mould and dust mites to thrive, it makes a house harder to heat.

A moisture barrier can make a difference to both your perception of warmth and your heating bill.

When Green Dog are installing under-floor insulation, it is most cost-effective (at the time and in the long run for that home) to do the vapour barrier as well.    Then you get moisture AND temperature wins which bring health benefits.

Don’t underestimate the value of ground vapour barriers in managing moisture in homes to get householders healthy (warm AND dry!)

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