EXPOL TIMBER UNDERFLOOR INSULATION
EXPOL R1.4 White, EXPOL R1.8 Black, EXPOL R2.5 and EXPOL R3.1 UnderFloor – the ultimate timber underfloor insulation.
Whilst available now EXPOL R2.5 & EXPOL R3.1 are specifically designed to meet the Building Code changes introduced 1 May 2023.
EXPOL provides EXPOL R1.4 White, EXPOL R1.8 Black, EXPOL R2.5 and EXPOL R3.1 UnderFloor Insulation is designed to fit between the joists under timber floors. Designed for both new and existing timber floors it has been trusted by Kiwis for more than 25 years.
EXPOL UnderFloor Insulation is easy-to-install and is available in 4 convenient joist widths 360, 410, 470, 560 (mm). It is the DIY solution that will keep your home warm, dry and healthy.
EXPOL UnderFloor Insulation comes with an EXPOL 50 Year Product Warranty and requires no maintenance.
EXPOL UnderFloor insulation is available from participating hardware stores nationwide – find your local outlet here.
- EXPOL R1.4 White UnderFloor Insulation contains recycled content and can be recycled.
- EXPOL R1.8 Black UnderFloor Insulation can be easily recycled.
- EXPOL R2.5 UnderFloor Insulation contains recycled content and can be recycled.
- EXPOL R3.1 UnderFloor Insulation can be easily recycled.
The Products
EXPOL R1.4 White UnderFloor Insulation is a rigid white panel manufactured from Expanded Polystyrene material, 1200mm in length manufactured in four standard widths. This proven solution for timber floor insulation has been trusted by Kiwis for over 25 years and contains recycled content.
Visit EXPOL R1.4 White UnderFloor Insulation 
EXPOL R1.8 Black UnderFloor Insulation is graphite infused Expanded Polystyrene supplied in the same sizes as the standard white Underfloor insulation. EXPOL R1.8 Black UnderFloor Insulation is a premium product which achieves superior R-values.
DO NOT STORE IN DIRECT SUNLIGHT! Product could be damaged and warranty will be void.
Visit EXPOL R1.8 Black UnderFloor Insulation
EXPOL R2.5 UnderFloor Insulation is EXPOL’s New Generation Underfloor R2.5 panel consciously designed and engineered to meet the new insulation standards introduced on 01 May, 2023.
Made from Expanded Polystyrene that contains recycled content it is 1200mm in length, 100mm thick and manufactured in four standard widths 360, 410, 470, 560. It is the ideal solution for normal New Zealand suburban environments or rural areas which do not have extreme temperatures. EXPOL R2.5 contains recycled content and can be recycled.
EXPOL R2.5 has an EXPOL 50 Year Product Warranty that gives you the satisfaction of knowing that you will have a warmer, drier, healthier home in winter.
EXPOL R2.5 UnderFloor Insulation is BRANZ appraised
EXPOL R2.5 UnderFloor Insulation
EXPOL R3.1 Black UnderFloor Insulation is the ultimate underfloor insulation. A rigid panel infused with graphite makes it up to 24% more efficient than EXPOL R2.5.
EXPOL R3.1 is ideal for extremely cold temperatures and windy environments and can be recycled. It is manufactured from Expanded Polystyrene material, 1200mm in length,100mm thick in four standard widths 360, 410, 470, 560.
EXPOL R3.1 has an EXPOL 50 Year Product Warranty that gives you the satisfaction of knowing that you will have a warmer, drier, healthier home in winter.
DO NOT STORE IN DIRECT SUNLIGHT!
Product could be damaged and warranty will be void.
EXPOL R3.1 Black UnderFloor Insulation
EXPOL UNDERFLOOR INSULATION VIDEOS
NEW – EXPOL R2.5 & 3.1 UnderFloor
R2.5 & R3.1 – FULL VIDEO
SIZES & R2.5 VERSUS R3.1
MEASURING JOIST WIDTH
SECURING R2.5 & R3.1
WIREGUARD
TESTING FLAMABILITY
EXPOL R1.4 & 1.8 UnderFloor
R1.4 & R1.8 – FULL VIDEO
SIZES & R1.8 VERSUS R1.4
MEASURING JOIST WIDTH
SECURING R1.4 & R1.8
WIREGUARD
TESTING FLAMABILITY
UNDERFLOOR INSTALLATION GUIDE
Download EXPOL UnderFloor Brochure
Download EXPOL UnderFloor BRANZ 256 APPRAISAL
For further installation guidelines: Refer to NZS 4246:2016 Energy efficiency – Installing insulation in residential buildings www.standards.govt.nz
System Components
Fixings
There are fixings specific to existing floors and new floors. They are made from non-corrosive nylon and are used to fix the EXPOL panels in place.
- Existing Floors: EXPOL Z Clips are designed as a push fit between the panel and the joist.
- New Floors: EXPOL Joist Saddles for 2.5 & R3.1 are designed to slip over the joist to support and secure the 100mm panel.
EXPOL WireGuard
EXPOL WireGuard a waxed paper strip to separate exposed electrical cables from the EXPOL insulation. Expanded Polystyrene in some cases reacts with the plasticiser and degrades the elastic properties of some electrical cables over a prolonged period.
Styro-FIX Construction Adhesive
Styro–FIX is an advanced single component polyurethane-based construction adhesive.
This powerful adhesive is developed especially for the construction industry and will bond most types of construction materials including timber (damp and dry), concrete, plasterboard, polystyrene and many other porous and non-porous substrates.
It bonds expanded polystyrene to most surfaces, delivers strong adhesion and rapid cure, it is gun-able and non-drip.
Why would I use EXPOL R1.4 or R1.8 verses R2.5 or R3.1?
All consents issued after 1st May 2023 will have to meet the new Building Code requirements for new builds and you need to use R2.5 or R3.1 depending on which climate zone you are in.
What is the difference between EXPOL R1.4 White UnderFloor Insulation and EXPOL R1.8 Black UnderFloor Insulation?
EXPOL R1.4 White UnderFloor Insulation and EXPOL R1.8 Black UnderFloor Insulation deliver R Values that meet and exceed building regulations.
EXPOL R1.4 White UnderFloor Insulation is the ideal solution for normal New Zealand suburban environments or rural areas which do not have extreme temperatures. EXPOL R1.4 White UnderFloor Insulation is BRANZ-appraised and has a 50-year product warranty. EXPOL R1.4 White UnderFloor Insulation has 25% recycled content and can be recycled. It is manufactured with consideration for the environment
EXPOL R1.8 Black UnderFloor Insulation incorporates graphite in the manufacturing process and is 30% more efficient than EXPOL R1.4 White UnderFloor Insulation. EXPOL R1.8 Black UnderFloor Insulation is ideal for extremely cold, windy and extreme environments. EXPOL R1.8 Black UnderFloor Insulation has a 50 year product warranty and can be recycled.
What is the difference between EXPOL R2.5 White UnderFloor Insulation and EXPOL R3.1 Black UnderFloor Insulation?
EXPOL R2.5 White UnderFloor Insulation and EXPOL R3.1 Black UnderFloor Insulation deliver R Values that meet and exceed the new Building Code changes introduced 1 May 2023.
EXPOL R2.5 White UnderFloor Insulation is the ideal solution for normal New Zealand suburban environments or rural areas which do not have extreme temperatures. EXPOL R2.5 White UnderFloor Insulation has a 50-year product warranty. EXPOL R2.5 White UnderFloor Insulation has 25% recycled content and can be recycled. It is manufactured with consideration for the environment
EXPOL R3.1 Black UnderFloor Insulation incorporates graphite in the manufacturing process and is 24% more efficient than EXPOL R2.5 White UnderFloor Insulation. EXPOL R3.1 Black UnderFloor Insulation is ideal for extremely cold, windy and extreme environments. EXPOL R3.1 Black UnderFloor Insulation has a 50 year product warranty and can be recycled.
Has EXPOL UnderFloor been BRANZ Appraised?
Yes – EXPOL R2.5 UnderFloor has a BRANZ Appriasal.
What is R-Value?
An R-Value is a rating which measures how well insulation can resist heat flow. ‘R’ stands for thermal resistance.
- R-Value level depends on a number of things such as the type
of material, its density and thickness. - Higher R-Value = Better insulation.
What sizes is EXPOL UnderFloor R1.4 or R1.8 Insulation supplied in?
EXPOL UnderFloor Insulation is available in 360mm, 410mm, 470mm & 560mm panel widths and are 1200mm long and 60mm thick.
What sizes is EXPOL UnderFloor R2.5 or R3.1 Insulation supplied in?
EXPOL UnderFloor Insulation is available in 360mm, 410mm, 470mm & 560mm panel widths and are 1200mm long and 100mm thick.
Where do you get EXPOL UnderFloor Insulation from?
EXPOL UnderFloor is available from Mitre 10, Bunnings, Carters, PlaceMakers, ITM, BuildLink, Timber World and other independent hardware and building supply stores nationwide.
How do I cut EXPOL UnderFloor Insulation?
Use a heavy duty utility knife with a slide out blade.
What if my joist widths differ from EXPOL UnderFloors insulations standard size panels?
EXPOL UnderFloor insulation panels have flexi-cut edges which allow the panels to compress 1mm to 2mm to fit varying floor joist spacings. If the panel it to wide for your joist width simply trim it to size. If the panel is not wide enough then simply cut a section out of another panel and insert it to make the combined panels fit the joist cavity.
What fixings do I use under an existing floor?
EXPOL Z Clips – these clips are a push fit and need no nails. Simply push the clip between the joist and the panel. You should use 2 brackets per panel positioned diagonally at the end of the panels.
What fixings do I use when laying down a new floor?
R1.4 or R1.8 use the a 60mm Galvanized Nail. Use two nails per panel positioned diagonally 200mm in from the end of the panel, and 60mm from the top of the joist. Then simply place the panel in the floor cavity and lay the flooring.
R2.5 or R3.1 use the 100mm EXPOL Joist Saddle Brackets which are designed to fit over the joist before you put the floor down. Use two brackets per panel positioned diagonally 200mm in from the end of the panel. The top of the brackets will fit flush with the top of the joist. Then simply place the panel in the floor cavity and lay the flooring.
Do I need to remove the foil between the joist before installing the underfloor panel?
Yes you do need to remove the existing foil between the joists before installing underfloor panels.
Do I need to leave an air gap between the panel and the floor?
No the panel gets installed hard up against the floor as per Insulation Installation 4246 standards.
Is EXPOL UnderFloor Insulation affected by moisture?
No, even in a extremely damp environment EXPOL UnderFloor performs well and will not let moisture through to the floor.
Does EXPOL UnderFloor Insulation have a product warranty?
Yes when installed to specifications it has a 50 year product warranty.
What are the benefits of EXPOL UnderFloor Insulation compared to soft installation?
EXPOL UnderFloor Insulation is rigid and will not sag, it does not absorb water and easy to install.
Does EXPOL polystyrene panel effect the plastic casing around electrical wiring?
Yes the plasticiser in the electrical wiring reacts with the polystyrene, use EXPOL WireGuard to create a barrier between the polystyrene and the wire casing. 50mm of WireGuard is included in each pack of panels.
Should wiring touch the EXPOL polystyrene panel?
No, there should always be a barrier between the wiring and the insulation.
Do I have to use WireGuard?
No, you can use anything that will create a barrier between the two such as duct tape, insulation tape etc. However we do recommend using EXPOL WireGuard.
Why does there need to be a barrier?
Because in the wiring there is a chemical called plasticiser which reacts with the polystyrene.
If wiring touches polystyrene is there a fire issue?
NO !!!! Absolutely not there has never ever been an issue with this causing a fire.
What happens to wiring if it touches polystyrene?
Nothing much at all other than where the two have touch the wiring may feel a bit sticky.
What shall I do when fitting EXPOL UnderFloor Insulation around plumbing?
Leave 100mm serviceable gap around all plumbing.
What happens to EXPOL UnderFloor Insulation in a fire?
EXPOL UnderFloor Insulation is is manufactured with flame retardant and will not support a fire.
Does EXPOL UnderFloor Insulation give off any toxic fumes?
EXPOL UnderFloor Insulation is flame retardant and will not support a fire.
Is EXPOL UnderFloor Insulation Rodent proof?
EXPOL UnderFloor Insulation does not offer any nutritive value to rodents but is not rodent proof.
FURTHER INFORMATION
SPECIFIERS, ARCHITECTS AND PLANNERS
For all specifying information, relevant product testing and other detailed information please refer to MasterSpec documents on www.masterspec.co.nz or contact EXPOL for an electronic copy.
BRANZ APPRAISAL
EXPOL R1.4 UnderFloor has a BRANZ appraisal.
See BRANZ certificate number 256.
INSULATION STANDARD
All EXPOL timber floor insulation solutions comply with the Australian and New Zealand Standard AS/NZS 4859.1:2002.
MANUFACTURING STANDARD
All panels have a yellow stripe down one edge to confirm compliance with manufacturing standard AS 1366 Part 3 1992 for SL grade.
For further, detailed information on all products contact EXPOL 0800 86 33 73