What Is Thermal Bridging, and How Do R7.0 and R8.0 Insulation Help?

If you're building or upgrading your ceiling insulation in Perth, understanding thermal bridging is key to making the most of high-performance products like R7.0 Earthwool batts or the new R8.0 range.

What Is Thermal Bridging?

Thermal bridging happens when heat travels through a building material that conducts energy better than the insulation around it. In ceilings and walls, this usually means timber or steel framing that bypasses your insulation layer and creates hot (or cold) spots in your home.

The result? Energy loss, inconsistent temperatures, and reduced insulation effectiveness — even if you’ve filled every cavity with batts.

Where It Occurs

• Ceilings: Joists and rafters can act as conductors between roof spaces and internal rooms
• Walls: Timber or steel studs allow heat to bypass insulation layers
• Slab edges and windows: Framing and poor sealing create unwanted pathways

Why It Matters in Perth

With extreme heat in summer and chilly winter mornings, Perth homes need to hold temperature consistently to remain comfortable and energy-efficient. Thermal bridging in your roof can undo much of the benefit you get from basic insulation if not addressed.

How R7.0 and R8.0 Insulation Helps

When you install R7.0 or R8.0 ceiling insulation, you're giving your home a much higher resistance to heat flow — even in areas where framing causes thermal bridging.

• R7.0 Earthwool Ceiling Batts offer 330mm thick coverage and excellent thermal resistance.
• R8.0 Earthwool (Coming Soon) provides maximum thermal performance where high ceilings or Passive House targets apply.

By increasing the insulation’s R-value, you reduce the relative impact of thermal bridging — even when it can't be eliminated. Essentially, the insulation around bridging materials works harder to keep temperatures stable.

How to Minimise Thermal Bridging Further

• Install high-density batts like Earthwool in every cavity
• Use ThermalBreak 7 foil under metal roofing for additional radiant barrier
• Seal gaps between insulation batts and joists with care
• Pair ceiling insulation with wall insulation and underfloor solutions

Is R8.0 Worth It Over R7.0?

For most homes, R7.0 ceiling insulation is more than enough to meet NCC requirements and dramatically reduce heat transfer. However, R8.0 may be preferred for:

• Homes in bushfire zones requiring higher performance
• Passive House or low-energy builds
• Ceilings with large surface areas and limited ventilation

Need Help Choosing the Right R-Value?

Choosing the right R-value can be tricky depending on ceiling access, roof type, and usage. Visit our R-value guide or talk to our team for tailored advice.

Have questions about thermal bridging or which insulation is right for your build? Call 0417 910 326 or shop ceiling insulation online for fast WA-wide delivery or same-day pickup.