50mm Isotherm Insulation

The 50mm Isotherm is a thin-profile polyester ceiling insulation manufactured from recycled PET plastic bottles. Its non-itch, fiber-free construction makes it comfortable to work with and safe to install without gloves or masks. This thickness is most often chosen for topping up older insulation or providing a light thermal layer in spaces where maximum R-value is not required.

Offering a product R-value of 0.79 m²·K/W and an installed R-value of 1.19 m²·K/W, it delivers a modest level of thermal resistance — suitable for warm climates or for supplementing existing ceiling insulation.

SABS Certification Status

Isotherm products no longer carry SABS approval, as they did not pass the most recent testing requirements set by the South African Bureau of Standards.

Where certification is mandatory — such as public tenders, schools, and healthcare facilities — it’s recommended to use alternatives like Aerolite or Knauf, which still hold full SABS compliance.

• Knauf vs Isotherm
• Aerolite vs Isotherm

50mm Isotherm Specifications

Benefits of 50mm Isotherm

• Perfect for top-ups – improves performance when layered over existing insulation.
• Installer safe – no itching, dust, or fiber irritation.
• Lightweight thermal layer – suitable for mild climate applications.
• Eco-friendly – made from recycled plastic bottles.
• Resilient – won’t decay, attract pests, or absorb large amounts of moisture.

Practical Installation Tips

• Use mainly as a supplementary layer to improve existing insulation levels.
• If installing alone, limit use to warmer areas where thermal demand is low.
• Ensure any existing insulation is in good condition and dry before adding a top-up layer.
• Avoid compressing the product to maintain its designed thermal performance.

Related Isotherm Options

• 145mm – maximum performance for cold climates (Zones 1 & 4).
• 135mm – ideal for Zones 2 & 6.
• 100mm – compliant for Zones 3 & 5.
• 75mm – topping up or use in milder regions.
• 50mm – lightweight top-up layer.
• 40mm – ultra-thin layer for specific retrofit projects.

Improve Your Ceiling Insulation

We supply and install 50mm Isotherm insulation throughout Johannesburg, Centurion, and Pretoria. Get in touch today for tailored advice, prompt delivery, and professional installation.