When building or renovating a home, one of the most common metrics we hear is R-value—the measure of how well insulation resists heat flow. But here’s something most people don’t know: even if you install high-R-value insulation, your home can still perform like it has almost no insulation at all… if it’s not sealed correctly.

This isn’t theory—it’s reality. And it’s backed by building science.

In a recent video by Matt Risinger, he demonstrates just how drastically insulation performance drops when coverage is incomplete, even if only by a few percent.

In the video, Matt uses R-values based on U.S. units; however, for the purpose of the local Australian context, we’ve provided equivalent Australian R-values in brackets.

The Scenario: R30 Insulation That Underperforms

Matt starts with 10 inches (approx. 250mm) of fiberglass insulation, rated at R3 (R0.5 AU) per inch for a total of R30 (R5.0 AU)

Using thermal modeling, he demonstrates how even small reductions in coverage drastically reduce the effective performance of the insulation.

What Happens When Insulation Coverage Drops?

• At 50% surface area insulated → 🔻 Effective R-Value: R2 (R0.33 AU) ❗️93% reduction in effectiveness
• At 96% surface area insulated → 🔻 Effective R-Value: R12 (R2.0 AU) ❗️59% reduction in effectiveness

Let that sink in. Even with 96% coverage, you lose more than half the insulation’s performance.

And here’s the critical point—even when insulation appears well installed, thermal bridging through the timber frame can significantly reduce effective R-value.

In typical Australian construction:

• Timber framing (90mm) has an R-value of just R0.66
• If timber makes up even 20% of the roof or wall area, and isn’t encapsulated by a continuous insulation layer, it can substantially degrade the overall thermal performance

✅ Lesson learned: Insulation is only as good as how well it is sealed.

The Solution: Seal Every Gap with Huntsman’s Heatlok Spray Foam Technology

So, how do you avoid performance drops from gaps, voids, moisture ingress or settling insulation?

You use a system that delivers 100% coverage, seals air leaks, and eliminates thermal bridging—Huntsman’s Heatlok spray foam insulation.

✅ Continuous insulation: Its closed-cell structure forms an unbroken layer over all surfaces, including framing, for maximum thermal efficiency.

Why Heatlok Spray Foam Works

Heatlok by Huntsman Building Solutions is a closed-cell spray foam that expands on application to create a continuous, gap-free layer of high-R-value insulation, moisture and air barrier all in one.

Unlike batt insulation, which must be cut to fit and often leaves voids, Heatlok naturally conforms to every surface, from framing corners to complex transitions.

Benefits of Heatlok Spray Foam:

• Seals Every Gap: Fills cracks, crevices, and voids for complete coverage
• Delivers True R-Value: No thermal bridging, settling, or compression
• Acts as an Air Barrier: Greatly reduces air leakage and energy loss
• Moisture Vapour Barrier: Blocks moisture transmission through the building envelope
• Structural Support: Adds up to 250% racking strength to the wall assembly

Real Efficiency Starts with Real Coverage

Whether you’re a builder, architect, or homeowner, what you install is important, but how it’s sealed is everything.

Stop trusting nominal R-values alone. Start looking at effective performance.

🔗 Watch Matt Risinger’s demo here: https://youtu.be/8yLo0us28A4

📩 For more information about Heatlok spray foam technology for your next project, contact Lachlan Simpson at 0411 690 565 or visit www.pacificurethanes.com