Ground Moisture Barrier

Protect your home against rising damp

The simplest way to reduce mould, mildew and rot

Properly installed polythene ground moisture barrier is the most effective way to address subfloor moisture


Much of New Zealand’s housing stock is built with suspended floors (on piles), with a staggering potential 40 litres per day evaporating into the crawl space and above, if no barrier is in place. (BRANZ information – based on 100sqm home).

This moisture can cause mould, mildew and rot, affecting your families health.

The new Healthy Homes Standards require that a Ground Moisture Barrier be installed by a professional so as to meet these standards.  As registered installers, we provide compliance certificates for all our insulation work.

We are based in Levin and install insulation from Wellington to Whanganui and surrounding areas.  Our business is insulation – and we know what we’re doing!

Common questions

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What is a Ground Moisture Barrier?

A Ground Moisture Barriers (GMB) is a polythene groundsheet that covers the underfloor of a home. When installed by a professional installer without gaps, rips or tears, it is an extremely cost effective method to prevent rising dampness.

Contact us today to book your free, no obligation assessment. 

Can I install a Ground Moisture Barrier myself?

Yes, it is possible to install a Ground Moisture Barrier yourself. To meet the Healthy Homes Standards requires the use of the correct grade of polythene, installed with no gaps, rips or tears.  Our experienced local team can manage this for you, providing a certificate of compliance on completion. Let’s face it; it’s not the nicest job getting under the underfloor!  

Is Ground Moisture Barrier covered by the Warmer Kiwi Homes grant?

If you are the homeowner and your property qualifies for a Warmer Kiwi Homes Insulation subsidy (ceiling or underfloor), then yes 80% of the cost of a Ground Moisture Barrier is covered.

Do I need a ground moisture barrier as part of the Healthy Homes for my rental property?

Yes, if your property requires ground moisture barrier because it has a suspended floor and 50% or more of the sub-floor perimeter is obstructed then a ground moisture barrier is required. It will need to be done to be able to get your healthy homes certificate for your rental property. 

Our customer feedback!

“I highly recommend you guys you have been outstanding to work with, great workmanship and we cannot fault you”

Harcourts Property Management

“It’s been a pleasure working with you [Sandra] and Chris. You’re a dynamic team.”

Rob, Builderscrack 

I have been on the phone with Chris a couple of times concerning issues regarding the installation and he was really helpful, taking the time to explain what was the issue and what needs to be resolved before he can complete the job. It has been easy to reschedule jobs with you and I’m really thankful for your flexibility.

Quinovic property management Whitby

Complete this form now, to find out if you, or your home, qualifies for an insulation grant

Book a FREE assessment today!

Insulation Tech NZ are the smart choice.

Book your FREE insulation assessment and one of the Insulation Tech NZ team will visit your property, check what you need and discuss what insulation you require for your home. You will be provided a report on what is required in your home based on which assessment you have booked.  We are registered providers for the Warmer Kiwi Homes Programme.

Call us now and our friendly team will book your measure and quote at a time that suits you.

Chris: 027 767 1472
Sandra: 027 568 1765

Mon – Fri: 7.00am – 6.00pm

Closed Saturdays, Sundays and Public Holidays (mostly!).

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