Knauf vs Aerolite Insulation: Which is Best for Your Ceiling?

When it comes to insulating your ceiling or roof in South Africa, two names stand out above the rest — Knauf and Aerolite. Both are premium glasswool products designed to keep your home cooler in summer, warmer in winter, and cut down on electricity costs.

But which is actually better for your needs? In this guide, we’ll compare Knauf vs Aerolite on density, acoustic performance, softness, fire safety, R-values, and price, so you can make the best decision for your home.

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Knauf vs Aerolite — Quick Overview

Knauf is a next-generation, high-performance glasswool insulation made with innovative ECOSE® Technology. It has a natural brown colour, ultra-soft, less itchy feel, and a cleaner, greener manufacturing process. Imported from Germany, Knauf is widely recognized for its exceptional comfort and superior acoustic performance, making it a top choice for homeowners seeking the best in thermal and sound insulation.

Learn more about Knauf Insulation →

Aerolite is South Africa’s most established and trusted insulation brand. Manufactured locally by Isover Saint-Gobain, this distinctive yellow insulation has been used in homes for over 90 years, delivering reliable thermal performance and long-lasting energy savings.

Learn more about Aerolite Insulation →

Both products are non-combustible ceiling insulation solutions, installed above the ceiling board between timber trusses, to maximise your home’s energy efficiency and comfort year-round.

Density & Acoustic Insulation

When comparing these two products, one of the key differences is density — a factor that directly impacts acoustic performance.

Knauf: ±12kg/m³
Aerolite: ±11kg/m³

That extra density gives Knauf a distinct advantage in sound absorption, making it noticeably better at reducing noise between rooms and from outside. It’s the ideal choice for homes near busy roads or for anyone who simply values a quieter, more peaceful indoor environment.

Learn more about noise reduction →

Comfort & Handling

Another big difference comes down to the feel of the insulation during installation.

Knauf is manufactured using ECOSE® Technology, a formaldehyde-free binder made from rapidly renewable organic materials. This makes it softer and less itchy, easier for installers to work with, and gentler on the skin.
Aerolite remains slightly more fibrous, though modern manufacturing has improved comfort significantly.

Installers generally prefer working with Knauf for its smooth texture, but both are fully safe to handle with standard protective gear.

Thermal Performance & R-Values

When it comes to keeping your home cooler in summer and warmer in winter, both Knauf and Aerolite deliver virtually identical thermal performance.

Thickness	Knauf R-Value	Aerolite R-Value
135mm	±3.38	±3.38
100mm	±2.50	±2.50
50mm	±1.25	±1.25

Both products exceed SANS 10400-XA building regulations for energy efficiency in South Africa.

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Fire Safety & Certifications

Safety is critical in any insulation product. Luckily, both options are:

Non-combustible (Class A1 fire rating) — they won’t burn, melt or propagate flames.
Certified to comply with South African standards, ensuring peace of mind for homeowners, architects, and builders.

Learn more about fire ratings →

Pricing & Availability

Aerolite is generally slightly more affordable per square meter, especially for smaller residential projects.
Knauf, while marginally higher in price, often makes sense on larger projects where acoustic comfort is a priority.

Both are stocked in multiple thicknesses — 50mm, 100mm, and 135mm — ready for delivery and installation across Johannesburg, Pretoria, Centurion, Durban, and Cape Town.

Knauf vs Aerolite — Quick Comparison Table

Feature	Knauf Earthwool	Aerolite
Density	±12kg/m³	±11kg/m³
Acoustic performance	★★★★★	★★★★☆
Softness / Handling	Softer (Less Itchy)	Slightly scratchy
Fire rating	Non-combustible A1	Non-combustible A1
Typical R-value @135mm	±3.38	±3.38
Price	Slightly higher	Slightly lower

So Which Should You Choose?

When it comes down to choosing between Knauf and Aerolite, it really depends on what matters most to you and your home. Both products deliver outstanding thermal insulation that will make your house cooler in summer, warmer in winter, and help you save on energy bills.

However, Knauf stands out for its superior acoustic performance and ultra-soft texture, making it the preferred choice for homeowners who want the best in comfort and noise control. Its higher density means it does a better job at absorbing sound — ideal if you live near busy roads or simply value a quieter indoor environment.

On the other hand, Aerolite remains an excellent option, especially if keeping initial costs down is your top priority. You’ll still enjoy long-lasting thermal protection and fire safety that meets all South African standards, but without quite the same level of noise reduction or installer comfort that Knauf offers.

Either way, investing in quality ceiling insulation like Knauf or Aerolite is one of the smartest decisions you can make for your home.

Get a Quote on Knauf or Aerolite Insulation

We’re authorized suppliers and installers of both Knauf and Aerolite insulation, delivering across Gauteng, KZN, Western Cape and beyond.

Or contact us for a free quote and we’ll help you choose the right insulation for your needs.