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The Truth About Thermal Bridging and How Super Therm® Solves It

Cool Surfaces | Insulation Coatings | Thermal Info | Urban Heat

Thermal bridging is one of the most underestimated causes of energy loss in buildings.

It does not matter how thick your insulation is.
If heat finds a path around it, performance drops. Fast.

Steel frames. Purlins. Roof screws. Concrete beams. Container ribs.
All of them conduct heat straight through the envelope.

And most building models barely address it.

What Thermal Bridging Actually Is

Thermal bridging occurs when a highly conductive material bypasses insulation and transfers heat directly through the building fabric.

Steel conducts heat at roughly 50 W/m·K.
Bulk insulation sits around 0.035–0.045 W/m·K.

That difference is not small. It is massive.

Every metal penetration through insulation becomes a heat highway.

This is well documented in building science literature and ASHRAE guidance on envelope performance.

When external temperatures spike, those bridges:

  • Drive internal heat gain
  • Increase HVAC load
  • Create condensation risk
  • Reduce real-world R-value performance

On steel structures, containers and industrial sheds, thermal bridging is not a minor issue. It is the dominant heat transfer pathway.

Why Bulk Insulation Does Not Fix It

Bulk insulation works on slowing conductive heat transfer.

But it does not eliminate conductive pathways.

If steel members connect exterior to interior, insulation only works between them.
Heat still flows through the metal.

This is why measured in-situ performance often falls below theoretical R-values.

Even high-end façade systems still struggle with:

  • Structural steel
  • Fasteners
  • Cladding rails
  • Window frames

The bridge remains.

The Surface Heat Problem Most People Miss

Thermal bridging is not just about conduction.

It starts with surface heat load.

When a roof or wall absorbs solar radiation, its temperature can exceed 70°C in Australian conditions. That heat then:

  1. Conducts through metal
  2. Radiates inward
  3. Drives internal air temperature up

If you reduce the surface heat load, you reduce the bridge effect.

That is the shift most specifications ignore.

How Super Therm® Changes the Equation

Super Therm® does not try to slow heat once it is inside the structure.

It blocks the heat load at the surface.

At a dry film thickness of 0.25 mm, it:

  • Reflects 97% of UV
  • Blocks 99% of infrared radiation
  • Delivers an average 96.1% total solar heat rejection
  • Exhibits extremely low thermal diffusivity

This means the substrate temperature remains significantly lower under solar load.

Lower surface temperature = lower conductive driving force through steel.

If steel never reaches extreme temperature, it cannot bridge that energy inside.

That is physics.

Unlike bulk insulation, this approach:

  • Coats the entire envelope
  • Covers steel, fixings and penetrations
  • Eliminates exposed conductive pathways at source
  • Reduces both radiative and conductive load

The City of Adelaide Cool Roof trial recorded internal reductions of up to 6°C below ambient conditions when applied correctly.

That result does not happen from R-value alone.

Diffusivity Matters More Than Most Admit

Conductivity measures how well heat flows through a material.

Diffusivity measures how fast temperature changes move through it.

Even a thin layer with low diffusivity dramatically slows temperature spikes moving into the structure.

This is why judging coatings by conductivity alone is flawed.

Thermal bridging is not just about steady-state heat transfer.
It is about transient heat load.

Australian buildings face extreme solar spikes.
Managing those spikes is critical.

Real-World Application: Steel Buildings and Containers

In steel sheds, transportables and containers:

  • There is minimal thermal mass.
  • Steel framing dominates conduction.
  • Insulation gaps are common.
  • Fasteners create hundreds of micro-bridges.

Applying Super Therm® externally transforms the thermal behaviour of the entire surface.

Instead of chasing internal insulation upgrades, you neutralise the heat load before it enters.

That reduces:

  • HVAC demand
  • Surface condensation
  • Structural expansion stress
  • Long-term fatigue from heat cycling

It also protects the substrate, unlike reflective paints that degrade rapidly.

The Bigger Issue

Most energy modelling tools still focus heavily on R-values.

They rarely account properly for:

  • Surface radiation blocking
  • Thermal diffusivity
  • Real-world solar intensity
  • Steel-dominant construction

That gap is why thermal bridging continues to be a hidden cost.

The industry keeps increasing insulation thickness.

Few address the heat source.

Blocking heat before it enters the envelope is the smarter strategy.


Final Position

Thermal bridging is real.
It is measurable.
And in metal-dominant construction, it is unavoidable if you rely solely on bulk insulation.

The solution is not always more thickness.

It is surface control.

Super Therm® works because it reduces the temperature differential driving the bridge in the first place.

Control the surface.
Reduce the load.
Lower the bridge effect.

That is performance grounded in thermodynamics, not marketing.


References


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