Ceiling Insulation

The best ceiling insulation is in blanket form as opposed to ceiling insulation segments - this is because it reduces heat loss that can occur through the joists and gaps between segments (known as thermal bridging)

There are three main forms of ceiling insulation:

Insulation Blanket:

This is a long roll of insulation that literally blankets your ceiling. It has the benefit of less joins for heat to escape through and covers the timber to avoid thermal bridging.

Insulation Segments:

The insulation is pre-cut into rectangles that sit between the timber framing in your ceiling. These are effective although heat can be lost between the segments and through the joists.

Loose-fill insulation:

This is a form of ceiling insulation we only recommend for difficult to access roof areas. Loose-fill insulation is blown into the roof using a machine. It is effective if your roof is so low you don't have access to install blanket although it does settle over time and can be blown out of place by draughts.

The thermal effectiveness of insulation is measured by its thermal resistance or R-Value. The New Zealand Building Code specifies minimum R-Values for ceiling insulation in different regions reflecting the climate. The minimum insulation level you need for different regions of New Zealand are:

• Zone 1 - Northland, Auckland, Coromandel: R-Value 2.9
• Zone 2 - Rest of the North Island except Central Plateau: R-Value 2.9
• Zone 3 - North Island Central Plateau and all of the South Island: R-Value 3.3

Remember that these are the minimum levels of ceiling insulation when retrofitting to an existing house and it is often worthwhile to install at a level above the very minimum. We recommend asking for a quote on the minimum level plus a higher R-Value and then make a call for what your budget can afford.

Since July 2019 it has been compulsory to have Ceiling Insulation in rental properties. The introduction of the Healthy Homes Standards raised the threshold of how much insulation was required from 70mm thickness to 120mm thickness. If ceiling insulation is not currently 120mm thick then it is required to add sufficient insulation to meet the NZ Building Code which is an R-value of 2.9 - 3.3 depending on which part of the country you're in.

Read more about Ceiling Insulation for rentals

There's a variety of ceiling insulation product types available in New Zealand now. For best results choose quality ceiling insulation that won't settle or degrade over time. We only use ceiling insulation that has been approved for use in EECA's Warmer Kiwi Homes insulation programme for homeowners. The two most used ceiling insulation materials are polyester and fibreglass (glasswool) insulation.

Polyester Insulation: A more modern insulation material is polyester which is the same sort of fibre as used in clothing, pillows and duvets. It's safe to touch, non-itch, non-irritant and also has no glues, resins, pesticides or formaldehyde. The polyester fibres are heat-bonded together for a long-lasting bond to keep your home warmer. Mammoth Modern Insulation is a polyester product and uses fibres from recycled plastic bottles in its manufacture as well.

Fibreglass (Glasswool) insulation: This is the traditional insulation that New Zealanders know and is made from spun glass fibres that are held together by glues and resins. Greater care must be taken when handling fibreglass or glasswool as it can cause irritations to the skin, eyes, throat and nasal passages. You need to wear goggles, gloves, overalls and a face ask during installation. We use Pink Batts and Bradford Gold glasswool insulation - both are trusted brands for ceilings and walls.

Read also about the different formats insulation is available in for ceilings.

You may already have ceiling insulation in your roof space but is it enough?

Standards have changed and if your insulation was installed before 2005 it may not have been enough. In addition some forms of ceiling insulation settle over time becoming less effective.

If you don't have sufficient we can help you with top-up ceiling insulation to lay over what you already have to improve efficiency. Contact us to get a free home assessment.

Insulating your ceiling is also a great time to consider switching to energy efficient LED downlights. In addition to having lower energy consumption you can reduce heat loss through the light fitting and reduce or eliminate the air space required in your insulation around traditional downlights.

If your home has a roof space sufficient that our installers can crawl around - then yes your ceiling can be insulated with ceiling blanket.

If your ceiling is too small for people to crawl around in - then in most regions we can assist with a blown-in insulation solution. Blown-in ceiling insulation can settle over time but it is better than no insulation at all.