Description
Polycell ThermaWrap 4mm Insulation Foil is a reflective foil insulation made from a closed-cell XPE foam core with a woven foil lamination. One face is bright aluminium foil and the other is a low-emissivity antiglare backing. Polycell describes it as a product used in construction to help keep indoors cool or warm.
ThermaWrap comes in three thicknesses: 4mm, 6.5mm and 8mm. The 4mm roll is the thinnest and lightest of the three. All three share the same core material and foil construction, and each is sold as a 30m² roll.
Polycell lists ThermaWrap for commercial roofing, residential roofing and external walls. Reflective foil works by facing an air gap, so the bright foil side should face the cavity it is meant to work across. Polycell’s current product page does not state R-values for ThermaWrap; the thermal result of a reflective foil depends mainly on the air gaps in the finished roof or wall, not on the foam thickness alone.
Technical Specifications
| Core | Closed-cell XPE foam |
|---|---|
| Surface | Bright aluminium foil, woven foil lamination |
| Backing | Low-emissivity antiglare |
| Thickness | 4mm (also available in 6.5mm and 8mm) |
| Pack size | 30m² roll |
Where to Use
- Commercial and residential roofing
- External walls, subject to the building code note below
How to Apply
- Plan the run: measure the roof or wall section against the 30m² roll to keep off-cuts down.
- Face the foil to the air gap: position the bright aluminium surface toward the cavity it needs to work across.
- Fix in place: staple or fix along the framing, keeping the sheet taut so it does not sag.
- Lap the joins: overlap adjoining runs so the foil layer is continuous.
- Finish the build-up: fit the roofing or cladding once the foil is fixed.
Important Notes
- Pickup only from our Keilor East yard.
- Install with the bright foil face toward an air gap; without one, a reflective foil does very little.
- Keep the roll dry before installation.
- Polycell’s current product page does not state R-values, vapour permeance or fire test results, so we do not quote them. Ask us for the manufacturer’s data sheet.
- For external walls, the National Construction Code sets vapour-permeability requirements for membranes behind cladding in Melbourne’s climate zone. A closed foil-faced product may not meet them, so check with your builder or building surveyor before using it in a wall.
