Knauf vs Fabufill Insulation (2026)

Knauf vs Fabufill Insulation – Which Is Better?

If you’re comparing Knauf vs Fabufill insulation, you’re looking at two commonly used ceiling insulation options in South Africa:

Knauf – glasswool insulation
Fabufill – polyester insulation

Both products are used as ceiling insulation in residential and commercial buildings, but they differ in performance, material properties, and long-term value.

You can also explore all our insulation comparisons to compare different materials, brands, and applications.

Here’s how Knauf and Fabufill insulation compare, including performance, pricing, and which option is better for your home.

Quick Answer

Best overall performance: Knauf
Best thermal efficiency: Knauf
Best fire resistance: Knauf
Best comfort (soft to handle): Fabufill

Both products work, but Knauf offers higher performance, while Fabufill focuses more on comfort and ease of handling.

Knauf vs Fabufill Comparison

Feature	135mm Knauf	145mm Fabufill
Material	Glass mineral wool	Polyester
Thermal Performance	High (R-value ±3.38)	Moderate (R-value ±3.17)
Fire Rating	Non-combustible (A1)	Lower resistance (B)
Acoustic Performance	Strong sound absorption	Low sound absorption
Density	Higher (12kg)	Lower (10kg)
Comfort (handling)	Soft-touch (low itch)	Very soft, non-irritating
Lifespan	Long-lasting and stable	Long-lasting and stable
Typical Price Range	±R899 per roll	±R710 per roll

Thermal Performance

Knauf is known for stronger thermal performance.

135mm Knauf provides an R-value of around 3.38
This helps reduce heat loss in winter and heat gain in summer

Fabufill still provides insulation, but due to its material and density:

Its thermal performance is generally lower compared to glasswool

Fire Safety

There is a clear difference here:

Knauf = A1 fire rating (non-combustible)
Fabufill = B-class fire rating (not combustible)

An A1 rating means the material is non-combustible and does not contribute to fire spread, which is a significantly higher standard than B-class insulation.

In most residential applications, both products are used safely, but Knauf offers a much higher level of fire resistance and overall fire safety.

If fire resistance and safety is a key requirement for your project, you can also all explore our fire-rated insulation products designed for high-risk and compliance-focused applications.

Acoustic Performance

Knauf performs well in reducing noise due to its higher density and mineral fibre structure.

At around 12kg/m³ density compared to Fabufill’s ±10kg/m³, Knauf glasswool is more effective at absorbing and dampening sound, particularly for airborne noise.

Fabufill still provides sound absorption and can improve overall comfort, but its lower density means it typically does not reduce noise to the same level.

For homes where noise reduction is important,
Knauf is generally the better choice for acoustic performance

Price and Value

Pricing between the two can appear similar at first, but the coverage per roll is different:

Knauf: ±R899 per roll (covers ±9m²)
Fabufill: ±R710 per roll (covers ±6m²)

When broken down per square metre:

Knauf ≈ R100/m²
Fabufill ≈ R118/m²

While Fabufill may seem cheaper per roll,
Knauf is still more cost-effective per m²

In addition to lower cost per coverage area, Knauf also provides stronger thermal, acoustic, and fire performance, making it the better overall value.