Isotherm Insulation

Isotherm Ceiling Insulation – Cape Town & West Coast Premium Polyester Insulation in 75mm, 100mm, 135mm & 145mm Thicknesses.

Isotherm Insulation is one of South Africa’s most trusted and popular ceiling insulation brands. Manufactured locally from 100% recycled polyester fibres (PET bottles), it is completely dust-free, non-allergenic, non-itch, and chemical-free — making it the safest and cleanest choice for families and professional installers.

Whether you need light top-up insulation or maximum thermal performance, Isotherm is available in four practical thicknesses so you can choose exactly what your home or commercial building requires.

Why Homeowners & Builders in Cape Town Choose Isotherm

• Keeps your home up to 7°C cooler in summer and warmer in winter
• Reduces heating and cooling costs by 40–70%
• Can save up to 21% on your monthly electricity bill
• Excellent sound absorption (great for noisy areas)
• Fire-rated and fully SANS 10400-XA compliant
• Lightweight, easy and safe to install — even DIY
• Maintenance-free and lasts for decades

Isotherm Specifications & Comparison Table

Thickness	R-Value	Roll Size	Coverage per Roll	Best For in Cape Town / West Coast	Recommended Use
145mm	3.37	5m × 1.2m	6 m²	Maximum performance in cold & windy areas	New homes, high ceilings
135mm	3.14	5m × 1.2m	6 m²	Excellent all-round thermal performance	Most residential homes
100mm	2.33	6m × 1.2m	7.2 m²	Standard modern homes	General use & renovations
75mm	1.53	8m × 1.2m	9.6 m²	Light top-up or warmer micro-climates	Existing ceilings, budget option

Isotherm Insulation Available Thickness & R-Values

145mm Isotherm Insulation

• R-Value: 3.21 (Installed 3.61)

• Excellent thermal resistance for ceiling insulation

• Ideal for colder climates or high-performance insulation needs

135mm Isotherm Ceiling Insulation

• R-Value: 3.14 (Installed 3.54)

• Excellent thermal resistance for ceiling insulation

• Ideal for colder climates or high-performance insulation needs

100mm Isotherm Insulation

• R-Value: 2.04

• Balances performance and affordability

• Common choice for standard residential homes and offices

How Isotherm Compares to Other Insulation Types

Isotherm is not as effective as traditional fibreglass and older materials in comfort and ease of use. Unlike fibreglass, it does not cause skin irritation or respiratory issues. It is also more environmentally friendly because it is made from recycled plastic bottles and requires far less energy to manufacture.

Perfect for Cape Town & Western Cape Homes

Our climate has big temperature swings — hot days and cold, wet winters. Isotherm’s R-values are specifically suited to the Western Cape. Installing the correct thickness (most homes do best with 135mm or 145mm) makes a dramatic difference in year-round comfort and electricity savings.

Easy Installation

Isotherm is lightweight and comes in convenient rolls. It can be installed between ceiling joists or in new drywall partitions with minimal tools. Many homeowners install it themselves, but we also offer professional installation across Cape Town, the West Coast, and surrounding areas.

Benefits of Isotherm

✔ Eco-friendly and sustainable
✔ Non-itch, allergy-free and easy to install
✔ Improves thermal comfort
✔ Reduces electricity usage for heating & cooling
✔ Suitable for ceilings, walls & floors
✔ Excellent acoustic damping
✔ Recyclable at end of life

Frequently Asked Questions

Q: Which thickness should I choose?

A: 135mm or 145mm is recommended for most homes in Cape Town and the West Coast for best results.

Q: Is Isotherm safe for children and pets?

A: Yes — it is non-allergenic, dust-free, and contains no harmful chemicals.

Q: Does it help with soundproofing?

A: Yes, Isotherm provides excellent acoustic insulation between floors and rooms.

Q: Is it fire-resistant? A:

No, it carries a B/B 1/2 fire rating. As a result, it is classified as combustible.

Is Isotherm eco-friendly?
Yes. It’s made from recycled PET plastic bottles, making it a sustainable insulation choice.

Is Isotherm safe to install?
Yes. It is non-allergenic, non-irritant and easy to handle without special protection.

Can Isotherm be installed over existing insulation?
Yes. It can be added on top of existing insulation to increase thermal resistance.

How long does Isotherm insulation last?
With proper installation, Isotherm performs reliably for decades, maintaining thermal properties over time.

Does Isotherm help with noise reduction?
Yes. Its structure also provides acoustic damping, reducing airborne noise within spaces.

Is Isotherm good for Cape Town’s climate?
With proper thickness (100mm+), Isotherm provides meaningful insulation in both hot and cool seasons.

What areas of my home can Isotherm be used in?
Ceilings, walls, ceilings with Isoboard, under floors, and any area needing thermal control.