Underfloor Insulation
Underfloor Insulation

If you have a suspended timber floor, Glasswool insulation is an ideal solution for providing thermal and acoustic performance.

Homes lose more energy through the floor and ceilings combined than through external walls. Installing insulation in the underfloor and ceiling will compensate for the walls being missed out. An un-insulated underfloor will lose up to 20 per cent of internal heating or cooling.

To help address the effects of wind-wash, there is a new insulation product available that comes with a wind-wash barrier. Earthwool® glasswool insulation: Underfloor roll with wind-wash barrier has a high thermal performance of R-1.7 and a wind-wash barrier to provide protection from air movement under the floor (wind-wash occurs when there is air movement across the face of unfaced products, which draws out heat energy to reduce thermal performance). Furthermore, it is easier to install as it can be directly stapled in place. View our install video for more information. 

Installation Instructions
Datasheet
DIY Installation Video

Underfloor Insulation Installation Instructions

EARTHWOOL® GLASSWOOL INSULATION: UNDERFLOOR ROLL WITH WIND-WASH BARRIER

These instructions should be read in conjunction with local standard 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. Under no circumstances are staples to be of metal or other conductive material. Installing underfloor insulation can be hazardous due to the working environment and electrical cables.

Do not start work until the site is safe!

Assess the underfloor 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: NZS 4246:2006. When insulating any floors, care should be taken to ensure that sub floor ventilation is maintained according to AS/NZS 1860 or heed the recommendations of particleboard/timber flooring suppliers.

TOOLS REQUIRED TO INSTALL EARTHWOOL® GLASSWOOL INSULATION:

  • Sharp knife for trimming insulation

  • Ladder

  • Suitable clothing (see our safety instructions and precautions)

  • Tape measure.

STEP 1

  • The rolls are manufactured at 600mm wide to suit joist spacings of up to 600 centres. The width of the underfloor roll must be a minimum of 50mm greater than the width of the cavity.

  • 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

  • If possible leave the insulation in the packs until you’re in position and ready to install.

  • Before installing the product measure and cut the roll into convenient and manageable lengths.

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

STEP 3

  • Before friction fitting each roll ensure you identify any electrical cabling. Extreme care must be taken not to staple through any electrical wiring.

  • Friction fit underfloor roll between the joists with the excess material folded down evenly either side.

  • When abutting insulation ensure there is a close firm fit with no 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.

  • Secure the insulation in place by stapling down the turndowns at 200mm centres. Secure one side of the roll before gently pulling the roll taut and securing the other side, working your way along the roll.

  • A clearance of 100mm should be left around all waste water pipes.

  • When abutting dwangs or nogs the roll should be installed 75mm longer in order to create a turn down, this is then fixed with staples.

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 underfloor and disposing of all rubbish and excess insulation responsibly.

For more installation advice watch our underfloor install video and read our electrical safety information before doing any work in the underfloor.

Installation Instructions

Earthwool® glasswool insulation: Quilted Underfloor batts

These instructions should be read in conjunction with local standards AS 3999 or NZS 4246 building regulations. Before you start installing, please make sure you are familiar with our Health and Safety Information contained in this document and conrmed Earthwool glasswool: Quilted Underfloor batts are suitable for your application. Ensure that you use tools and equipment that are suitable for the intended application. This will include suitable safety equipment. Try and avoid staples made from metal or other conductive materials if possible. Installing underfloor insulation can be hazardous due to the working environment and electrical cables.

Do not start work until the site is safe!

Assess the underfloor 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. When insulating any floors, care should be taken to ensure that sub-floor ventilation is maintained according to AS/NZS 1860 or heed the recommendations of particleboard/timber flooring suppliers. Try and avoid staples made from metal or other conductive materials if possible. Installing underfloor insulation can be hazardous due to the working environment and electrical cables.

TOOLS REQUIRED TO INSTALL EARTHWOOL® GLASSWOOL INSULATION:

  • Sharp knife for trimming insulation

  • Ladder or suitable scaffold

  • Suitable clothing (see our safety instructions and precautions)

  • Tape measure

  • Staple.

Application:

Earthwool® glasswool: Quilted Underfloor batts come in long 2.7m batts and are suitable for most sub-floor applications including pole houses and open sub-floors. It is designed for use above “non-occupied” spaces such as the following:

  • Sub-floor with timber battens

  • Pole house

  • Sub-floor solid perimeter.

When installed above “occupied spaces”, such as workshops, garages, and basements, a suitable compliant lining such as plasterboard or fibre cement should be installed over the insulation. Alternatively, we recommend installing Earthwool glasswool: Undefloor roll with a wind-wash barrier. Product codes 546235 (500mm) and 492704 (600mm).

  • Workshop with lined floor joist

  • Garage with lined floor joist

  • Basement rooms with lined floor joist.

STEP 1

  • To calculate the number of packs needed, determine the area (m2) to be insulated by multiplying the length by the width. 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, and if the insulation is being folded down into a narrower space.

  • If possible leave the insulation in the packaging until you're in position and ready to install.

STEP 2

  • The batts are manufactured at 470mm wide to suit joist spacing’s of up to 515mm centres. The grey coloured protective plastic should be facing down, and the thinner brown plastic should be placed against the floorboards.

  • The underfloor batt fits between the joists with the plastic tabs folded down at right angles on either side.

  • Fix staples 65mm from the underside of the flooring to allow the Glasswool to fill the space above.

  • Ensure there are no air-gaps between the insulation and the floor. If the spacing is less than 470mm, compress the additional insulation into the cavity and continue to fix the tabs as above.

  • Before installing each batt, ensure you identify any electrical cabling. Extreme care must be taken not to staple through any electrical wiring.

  • Secure the insulation in place by stapling along the plastic tabs at a minimum of 200mm centres.

  • The batts can be easily cut to a manageable length.

  • Secure one side of the batt before gently pulling the plastic -lm taut and securing the other side, working your way along the segment.

  • When abutting to dwangs or nogs the segment should be installed 50mm longer in order to create a turn down, this is then fixed with staples.

  • When abutting insulation, ensure there is a close firm fit with no gaps.

  • A clearance of 100mm should be left around all waste water pipes. When insulating any floors, care should be taken to ensure that subfloor ventilation is maintained according to E2/AS1 design requirements for New Zealand and the NCC sub-floor ventilation retirements in Australia or head the recommendations of particleboard/timber flooring suppliers.

  • Insulation should be installed in accordance with local standards AS 3999 and NZS 4246.

For Pole Houses:

  • Increase the staples to 100mm centres.

  • Tape joins with a suitable tape.

  • Ensure that all loose material is secured to protect from wind damage.

STEP 3

  • 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 underfloor and disposing of all rubbish and excess insulation responsibly.

We recommend that once completed another person checks the work to ensure it has been installed according to required standards.