Ceiling Insulation

Ceiling Insulation
Ceiling Insulation

Did you know over 30 per cent of the heat in a home can be lost through an uninsulated ceiling? Insulating the ceiling is an easy way to create a more comfortable home, and save money on your heating and cooling bills. 

Why It's Important

Ceiling insulation will provide a thermal barrier to prevent the transfer of heat energy coming in and out of the home. Installing insulation will not only improve the comfort of the home but also save up to 30 per cent1 on heating and cooling energy bills.

Glasswool insulation is the most common insulation used in ceiling spaces. Made using recycled glass, it is non-combustible and is one of the most sustainable insulation products available. Ceiling insulation is easy to install and can be done as a DIY project. For guidance on installation in New Zealand reference NZS 4246:2006 and our installation instructions before carrying out any work.

1. Smarter Homes.org.nz, 2008
Installation Instructions
Datasheet
DIY Installation Video

Ceiliing Insulation Installation Instructions

These instructions should be read in conjunction with local standards NZS 4246 and all applicable local, state and federal building regulations.
Before you start installing, please make sure you are familiar with our safety instructions and precautions.
Ensure that you use tools and equipment that are suitable for the intended application. This will include suitable safety equipment.

Do not start work until the site is safe!

Assess the ceiling condition and structure together with the method of installation you are to use based on the appropriate requirements established in the Building Code, site assessment and or plans provided. Installation must be completed to the requirements of relevant standard: AS 3999:1992 or NZS 4246:2006.

TOOLS REQUIRED TO INSTALL EARTHWOOL® GLASSWOOL INSULATION:

  • Sharp knife for trimming insulation

  • Ladder

  • Suitable clothing (see our safety instructions and precautions)

  • Tape measure

  • Non-conductive insulation stick for positioning insulation in hard to reach areas

  • Kneeling board to span ceiling framing.

STEP 1

  • Determine the most suitable product for your project. Ceilings can be insulated using blanket or batts.

  • Where you have existing insulation that is level with the ceiling joists, you can install additional insulation over the top. It is recommended that this is installed at right angles to the existing insulation.

  • Insulation is available in varying widths and thicknesses to suit most framing spaces. Please check Knauf Insulation’s product guide for the most suitable product for your application.

  • To calculate the number of packs needed, determine the area (m²) to be insulated by multiplying the length by the width or wall height. The number of m² of insulation material is clearly marked on each pack. Divide the total area to be insulated by the m² in a pack to determine the number of packs required (don’t forget to round up to the nearest whole pack). Allowances should be made for areas that are unable to be insulated.

STEP 2

  • Don’t take the insulation out of the packages until you’re in position and ready to install.

  • Before installation, gently agitate the insulation by ‘bouncing’ it on its side until it recovers to thickness stated on the label.

  • Do not block ceiling vents and take care around downlights and other sources of heat. Consult the appliance manufacturer’s instructions for appropriate clearances. Additional guidance is provided in AS 3999 and NZS 4246.

STEP 3

  • Start installing the insulation at the far corners of the roof and work your way back towards the ceiling access.

  • When installing insulation between ceiling joists, ensure that you achieve a snug fit avoiding any gaps.

  • When installing insulation in truss roofs, ensure that insulation is firmly butted together to achieve a consistent layer of insulation without any gaps.

  • Where required, use a sharp knife to cut the insulation to fit. It is important that when you cut the insulation that you avoid coming into contact with any electrical services.

  • When installing insulation in a roof eave (i.e. where the roof joins the ceiling), make sure the insulation covers the top plate but is not in contact with the roof. It is important to maintain a 20mm gap between the roofing substrates and the insulation.

STEP 4

  • Complete a final check of the installation ensuring all areas have been insulated and that you have an even and consistent layer of insulation.

  • Finish your project by removing all packaging from the ceiling and disposing of all rubbish and excess insulation responsibly.

STEP 5

  • Once you have worked your way back to the ceiling access, make sure you insulate the ceiling access panel before exiting the roof space.

For more installation advice watch our ceiling install videos and read our electrical safety information before doing any work in the ceiling space.

Skillion Roof Installation Instructions

These instructions should be read in conjunction with local standards NZS 4246 and all applicable local, state and federal building regulations.
Before you start installing, please make sure you are familiar with our safety instructions and precautions. Ensure that you use tools and equipment that are suitable for the intended application. This will include suitable safety equipment.

Do not start work until the site is safe!

Assess the ceiling condition and structure together with the method of installation you are to use based on the appropriate requirements established in the Building Code, site assessment and or plans provided. Installation must be completed to the requirements of relevant standard: AS 3999:1992 or NZS 4246:2006.

TOOLS REQUIRED TO INSTALL EARTHWOOL® GLASSWOOL INSULATION:

  • Sharp knife for trimming insulation

  • Ladder

  • Suitable clothing (see our safety instructions and precautions)

  • Tape measure

  • Non-conductive insulation stick for positioning insulation in hard to reach areas

  • Kneeling board to span ceiling framing.

Install instructions

  • Determine the width of insulation needed by measuring the typical distance between ceiling joists.

  • Determine the maximum thickness of insulation that can be installed by subtracting 25mm from the depth of the available cavity.

  • When installing the insulation, ensure that you achieve a snug fit avoiding any gaps.

  • Butt insulation firmly against both the top plate of the wall at the bottom and the ridge joist at the top of the cathedral ceiling.

  • Do not push the insulation completely into the joist cavity. The front face of the segment should be flush with the face of the ceiling joist, leaving at least a 25mm airspace between the insulation and the underside of the roof deck.

  • Do not compress insulation or block ventilation. Please consult with your local codes and practices to determine the required ventilation and ventilation baffle requirements in cathedral ceiling applications.

  • When installing insulation into existing cathedral ceilings where roofing material is required to be removed, please refer to local or state authorities as specific requirements around the removal and replacement of roofing materials may apply.