Description
Polycell ThermaWrap 8mm Insulation Foil is the thickest option in the ThermaWrap range, built on the same closed-cell XPE foam core construction as the 4mm and 6.5mm rolls but with the deepest core for jobs that need the most thermal resistance the range offers. A bright aluminium foil surface reflects radiant heat, and a low-emissivity antiglare backing cuts on-site glare while leaving the reflective performance of the foil face untouched.
Choosing 8mm over the thinner options is a genuine call for a particularly exposed wall elevation, a colder climate zone, or simply wanting the highest thermal resistance the ThermaWrap range can offer within the same product family, rather than switching to a different insulation system altogether. The woven foil lamination is unchanged from the rest of the range, keeping the roll tear-resistant despite the deeper, slightly stiffer core underneath it.
It’s built for the same commercial and residential roofing and external wall applications as the 4mm and 6.5mm ThermaWrap rolls, and installs the same way — fixed to framing with the reflective foil face oriented toward the air gap it needs to work across. This 8mm roll is supplied as a 30m² pack, the same coverage as the rest of the range, so a job that steps up thickness on more exposed elevations doesn’t need separate coverage calculations.
Because the core stays closed-cell at this thickness too, it doesn’t pick up moisture sitting exposed on site before the roof or wall cladding goes over the top, which matters more the longer a thicker roll might sit staged before installation on a larger job. Getting the foil orientation and joint laps right remains what actually delivers the extra thermal resistance this thickness is chosen for.
Technical Specifications
| Core | Closed-cell XPE foam |
|---|---|
| Surface | Bright aluminium foil, woven lamination |
| Backing | Low-emissivity antiglare |
| Thickness | 8mm (also available in 4mm, 6.5mm) |
| Pack size | 30m² roll |
Where to Use
- Commercial and residential roofing
- External wall construction on more exposed elevations
- Colder-climate builds needing the highest thermal resistance in the ThermaWrap range
How to Apply
- Plan the run — measure the roof or wall section against the 30m² roll to minimise off-cuts.
- Orient the foil face — position the bright aluminium surface toward the air gap it needs to reflect across.
- Fix in place — staple or fix along the framing, keeping the woven foil surface taut to avoid sagging.
- Overlap joins — lap adjoining rolls to maintain a continuous reflective barrier.
- Complete the build-up — proceed with roofing or cladding over the top once the foil is fixed.
Important Notes
- Orientation of the reflective foil face affects thermal performance — install with the foil facing the air gap.
- Keep the roll dry prior to installation to protect the foil surface.
- Also available in 4mm and 6.5mm thicknesses for lighter-duty applications.

