Isoboard Ceiling Prices, Sizes, R-Values & Specifications South Africa

Isoboard Ceilings South Africa

Isoboard ceilings have become one of the most popular thermal ceiling systems in South Africa due to their excellent insulation properties, lightweight construction, moisture resistance and attractive finished appearance. Manufactured from high-density extruded polystyrene (XPS), Isoboard ceiling panels provide both a finished ceiling surface and thermal insulation in a single product.

Unlike conventional ceilings that require separate insulation products, Isoboard combines ceiling and insulation performance into one system, helping homeowners, builders and commercial property owners improve indoor comfort while reducing energy consumption throughout the year.

At Roof Insulation South Africa, we supply a complete range of Isoboard ceiling products including, 30mm, 40mm, 50mm and 80mm thicknesses. Whether you are building a new home, upgrading an existing property or improving the thermal performance of a commercial building, Isoboard provides an attractive and energy-efficient ceiling solution.

What Is Isoboard?

Isoboard is a high-density extruded polystyrene insulation board designed for thermal insulation applications in residential, commercial and industrial buildings. The closed-cell structure prevents moisture absorption while providing excellent thermal resistance and long-term durability.

One of the unique advantages of Isoboard ceilings is that the product serves as both a decorative ceiling finish and an insulation system. This reduces installation time while improving the overall thermal performance of the building.

Key characteristics include:

• Closed-cell extruded polystyrene construction
• Lightweight and easy to install
• Moisture resistant
• Excellent thermal insulation properties
• Long service life
• Attractive finished appearance
• Low maintenance requirements
• Suitable for residential and commercial applications

Isoboard ceiling panels are commonly installed directly onto timber or steel roof structures and can be used in homes, offices, schools, churches, agricultural buildings and industrial facilities.

Why Choose Isoboard Ceilings?

South African buildings are exposed to extreme temperature variations throughout the year. Roof spaces can exceed 50°C during summer while significant heat loss can occur during winter.

Installing Isoboard ceilings provides several important benefits:

Improved Thermal Comfort

Isoboard helps reduce heat transfer through the roof, keeping homes cooler during summer and warmer during winter.

Lower Electricity Costs

By reducing heat gain and heat loss, air conditioners and heaters operate more efficiently, reducing energy consumption.

Finished Ceiling And Insulation In One

Unlike traditional ceiling systems requiring separate insulation products, Isoboard combines both functions into a single installation.

Moisture Resistance

The closed-cell structure prevents moisture absorption and helps maintain long-term performance.

Attractive Appearance

Isoboard creates a clean, neat ceiling finish suitable for residential and commercial properties.

Lightweight Construction

The lightweight design simplifies installation and reduces structural loading.

Long-Term Durability

Isoboard provides many years of reliable thermal performance with minimal maintenance.

Isoboard Ceiling Sizes & Specifications

Isoboard ceiling panels are available in a range of thicknesses to suit different insulation requirements and budgets.

Thickness	Width	Available Lengths	Application
30mm	600mm	1.8m – 8m	Standard residential ceilings
40mm	600mm	1.8m – 8m	Improved thermal performance
50mm	600mm	1.8m – 8m	Popular residential option
80mm	600mm	1.8m – 8m	Maximum thermal insulation

The most suitable thickness depends on climate conditions, budget and required thermal performance.

30mm Isoboard Ceilings

30mm Isoboard ceilings provide an economical solution for homeowners seeking improved comfort and thermal performance without significant additional cost.

Applications include:

• Residential homes
• Holiday homes
• Garages
• Workshops
• Offices

Benefits include:

• Affordable insulation solution
• Improved indoor comfort
• Attractive ceiling finish
• Fast installation
• Reduced heat transfer

30mm Isoboard is often selected where moderate thermal improvement is required while maintaining budget control.

 

40mm Isoboard Ceilings

40mm Isoboard ceilings provide improved thermal performance compared to standard 30mm panels and are a popular choice for homeowners looking to increase comfort levels throughout the year.

The additional thickness improves resistance to heat transfer, helping maintain more stable indoor temperatures during both summer and winter.

Common applications include:

• Residential homes
• Townhouses
• Retirement villages
• Holiday properties
• Offices

Benefits of 40mm Isoboard include:

• Improved thermal insulation
• Better energy efficiency
• Reduced cooling costs during summer
• Enhanced winter comfort
• Attractive finished ceiling appearance

Many homeowners choose 40mm Isoboard as a balance between affordability and thermal performance.

50mm Isoboard Ceilings

50mm Isoboard ceilings are one of the most popular options available in South Africa. The increased thickness provides significantly improved thermal insulation and greater energy efficiency compared to thinner ceiling systems.

This thickness is particularly well suited to:

• New residential homes
• Renovation projects
• Premium residential developments
• Commercial offices
• Schools and educational facilities

Advantages include:

• Improved indoor comfort
• Lower heating and cooling costs
• Reduced heat gain through the roof
• Enhanced building energy efficiency
• Long-term electricity savings

For many South African homeowners, 50mm Isoboard offers one of the best combinations of performance, comfort and value.

80mm Isoboard Ceilings

80mm Isoboard ceilings provide the highest thermal performance within the standard Isoboard ceiling range.

These panels are commonly selected for:

• Energy-efficient homes
• Coastal properties
• Luxury residences
• Commercial buildings
• Agricultural buildings
• Specialised thermal applications

Benefits include:

• Maximum thermal resistance
• Outstanding summer heat reduction
• Improved winter heat retention
• Lower energy consumption
• Exceptional long-term performance

For property owners seeking the highest possible insulation performance, 80mm Isoboard represents the premium solution.

Isoboard Ceiling Prices South Africa

One of the most common questions asked by customers is: “How much do Isoboard ceilings cost?”

The cost of Isoboard ceilings depends on several factors including:

• Thickness selected
• Ceiling area
• Panel length required
• Delivery location
• Installation requirements
• Project complexity

Generally, thicker panels provide greater thermal performance but carry a higher material cost.

While the initial investment may be higher than conventional ceiling systems, many property owners recover part of the cost through reduced heating and cooling expenses over time.

For accurate pricing, we recommend requesting a quotation based on your specific project requirements.

Understanding Isoboard R-Values

The R-value measures a material’s resistance to heat transfer. The higher the R-value, the better the insulation performance.

Benefits of higher R-values include:

• Reduced summer heat gain
• Reduced winter heat loss
• Improved indoor comfort
• Lower electricity costs
• Better overall building efficiency

For South African conditions, selecting the correct insulation thickness can make a significant difference to indoor comfort and long-term energy savings.

When comparing ceiling systems, R-values provide one of the most useful indicators of thermal performance.

Isoboard vs Summit XPS Ceilings

Many customers compare Isoboard ceilings with Summit XPS ceilings because both products are manufactured from extruded polystyrene and provide excellent thermal insulation.

Similarities

Both products offer:

• Closed-cell XPS construction
• Excellent insulation properties
• Moisture resistance
• Lightweight installation
• Long service life
• Attractive appearance

Differences

The primary differences generally relate to:

• Product branding
• Available profiles
• Project requirements
• Installation preferences

Both systems can provide excellent thermal performance when correctly installed.

The best option often depends on project specifications, budget and personal preference.

Isoboard For Brick Cavity Wall Insulation

One of the lesser-known applications for Isoboard is cavity wall insulation.

Premium residential developments often install Isoboard between brick walls to improve thermal efficiency and reduce heat transfer through external walls.

Benefits include:

• Improved thermal performance
• Reduced heat gain
• Reduced heat loss
• Improved indoor comfort
• Greater energy efficiency

Cavity wall insulation is particularly beneficial in areas experiencing large seasonal temperature variations.

Isoboard Underfloor Insulation

Isoboard can also be installed beneath concrete floor slabs and flooring systems to reduce heat loss through the floor structure.

Underfloor insulation is commonly used in:

• Luxury homes
• Coastal properties
• Cold climate regions
• Commercial buildings

Benefits include:

• Warmer floor surfaces
• Improved comfort
• Reduced energy costs
• Enhanced thermal performance

This application is becoming increasingly popular in energy-efficient building projects throughout South Africa.

 

Isoboard Ceiling Installation Guide

Correct installation is essential to achieve the maximum thermal performance and lifespan from Isoboard ceiling systems.

Isoboard panels are lightweight and easy to install, making them suitable for both residential and commercial projects.

Installation On Timber Roof Trusses

The most common application is installation directly onto timber roof trusses.

Benefits include:

• Fast installation
• Secure fixing
• Clean appearance
• Excellent thermal performance

Installation On Steel Roof Structures

Isoboard ceilings can also be installed on steel roof structures commonly used in commercial and industrial buildings.

Finishing And Trims

Finishing trims create a professional appearance and help ensure a neat installation.

Proper installation techniques contribute significantly to the long-term appearance and performance of the ceiling system.

 

Residential Applications For Isoboard Ceilings

Isoboard ceilings are widely used in residential construction throughout South Africa.

Popular applications include:

• Family homes
• Townhouses
• Apartments
• Holiday homes
• Retirement villages
• Residential estates

Homeowners choose Isoboard because it provides both a finished ceiling and thermal insulation in a single product.

Benefits include:

• Improved indoor comfort
• Reduced electricity costs
• Better temperature control
• Attractive ceiling finish
• Long-term durability

Commercial Applications For Isoboard Ceilings

Commercial buildings often experience significant heat gain through the roof structure.

Isoboard ceilings are regularly installed in:

• Office buildings
• Schools
• Universities
• Churches
• Retail centres
• Medical facilities
• Warehouses
• Agricultural buildings

The combination of thermal insulation and finished appearance makes Isoboard a practical solution for many commercial projects.

Why Choose Roof Insulations South Africa?

With more than 36 years of insulation industry experience, Roof Insulations South Africa has supplied insulation products to residential, commercial and industrial projects throughout the country.

Our experience includes:

• Residential insulation projects
• Commercial insulation systems
• Industrial insulation applications
• Acoustic insulation solutions
• Thermal ceiling installations
• Technical product support

We offer:

• Expert advice
• Competitive pricing
• Nationwide delivery
• Quantity calculations
• Technical assistance
• Fast quotations
• Quality insulation products

Whether you require a single room or a large commercial project, our team can assist with selecting the most suitable Isoboard solution.

Frequently Asked Questions About Isoboard Ceilings

What is Isoboard?

Isoboard is a high-density extruded polystyrene (XPS) insulation board used for thermal insulation, ceiling systems, cavity wall insulation and underfloor insulation applications.

Is Isoboard a good ceiling material?

Yes. Isoboard combines insulation and ceiling finishing in one product, making it one of the most energy-efficient ceiling systems available.

Is Isoboard waterproof?

Isoboard is highly moisture resistant due to its closed-cell structure and does not absorb water like many other building materials.

Does Isoboard reduce electricity costs?

Yes. By reducing heat transfer through the roof structure, Isoboard helps lower heating and cooling costs throughout the year.

Which Isoboard thickness is best?

The best thickness depends on the application and insulation requirements.

• 30mm for basic thermal improvement
• 40mm for enhanced performance
• 50mm for excellent residential performance
• 80mm for maximum thermal efficiency

What lengths are available?

Isoboard is available in lengths ranging from approximately 1.8m to 8m depending on project requirements.

Can Isoboard be painted?

Yes. Isoboard ceilings can be painted using suitable coatings recommended for polystyrene-based products.

Does Isoboard help keep homes cool?

Yes. Isoboard significantly reduces heat entering through the roof, helping keep indoor spaces cooler during summer.

Does Isoboard help during winter?

Yes. Isoboard reduces heat loss through the ceiling and helps maintain warmer indoor temperatures.

Is Isoboard suitable for coastal areas?

Yes. The moisture-resistant properties make Isoboard suitable for coastal environments.

Can Isoboard be used between brick walls?

Yes. Isoboard is often installed within cavity walls to improve thermal performance in premium residential buildings.

Can Isoboard be used under floors?

Yes. Isoboard is widely used beneath floor slabs and flooring systems to improve thermal efficiency.

How long does Isoboard last?

When correctly installed, Isoboard can provide decades of thermal performance with minimal maintenance.

Is Isoboard environmentally friendly?

By improving building energy efficiency and reducing heating and cooling requirements, Isoboard contributes to lower energy consumption.

Does Isoboard attract insects?

No. Isoboard does not provide a food source for insects or rodents.

Can Isoboard sag over time?

When correctly installed according to manufacturer recommendations, Isoboard provides excellent long-term stability.

Is Isoboard suitable for offices?

Yes. Isoboard is widely used in office buildings and commercial properties.

Is Isoboard suitable for schools?

Yes. Schools frequently use Isoboard due to its thermal performance and attractive appearance.

Is Isoboard suitable for warehouses?

Yes. Isoboard can be used in warehouses and industrial facilities where thermal control is important.

Do you offer nationwide delivery?

Yes. We supply Isoboard ceiling products throughout South Africa.

Do you offer installation services?

Installation services are available in selected regions. Contact us for assistance and project-specific quotations.

Request A Quote For Isoboard Ceilings

Whether you require 30mm, 40mm, 50mm or 80mm Isoboard ceilings, our experienced team can assist with product selection, quantity calculations, pricing and delivery.

Contact Roof Insulations South Africa today for expert advice and a competitive quotation on your next Isoboard ceiling project.

 

All Isoboard Specifications

Thermal Performance

Specification	30mm	40mm	50mm
R-Value	1.143	1.524	1.905
U-Value (W/m²K)	0.875	0.656	0.525
K-Value (Thermal Conductivity)	–	–	0.02624 W/M.K

Specification	Value
Compressive Strength	±250 – 300 kPa
Load Bearing	High
Dimensional Stability	Excellent
Edge Profile	Square / Shiplap (depending on product)

 

Isoboard Moisture & Durability

Specification	Value
Water Absorption	<1% (very low)
Moisture Resistance	Waterproof structure
Mould Resistance	Will not support mould
Longevity	30+ years

 

BEST USE CASE

Application	Suitability
Ceilings (below roof sheets)	Excellent
Concrete slabs	Excellent
Underfloor insulation	Excellent
Industrial/commercial	Excellent
Acoustic insulation	Poor

Put this in a clean table or accordion.

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Isoboard Ceiling Board Specifications

Thickness	Thermal Resistance (R-Value)*	Panel Type	Material	Moisture Resistance	Fire Behaviour	Application
30mm	±1.05	Rigid Board	XPS	Excellent	Self-extinguishing	Ceilings
40mm	±1.40	Rigid Board	XPS	Excellent	Self-extinguishing	Ceilings
50mm	±1.75	Rigid Board	XPS	Excellent	Self-extinguishing	Ceilings
80mm	±2.80	Rigid Board	XPS	Excellent	Self-extinguishing	Ceilings

*R-values may vary slightly by batch/manufacturer.

Isoboard vs Summit XPS Ceilings

A short comparison table: