Glasswool ceiling insulation
135mm Aerolite Insulation
Comfort starts above your ceiling. 135mm Aerolite insulation is a flexible glasswool blanket for reducing heat transfer through the ceiling. Each Soft Touch roll covers 6m², measures 5m × 1.2m and has a material R-value of 3.38m²·K/W.
Check the current roll price, calculate your whole-roll quantity and plan your material order below.
starts above the ceiling.
01 / Plan your order
Comfort, by the roll.
One product. Clear coverage. The quantity you need.
per roll
R99,84 per m² ·
Materials pricing. Confirm delivery charges, availability and any installation requirements before ordering.
02 / Plan your project
Your ceiling. Your numbers.
Calculate the whole rolls needed for your ceiling area.
For several rooms, enter their combined ceiling area.
Choose an allowance for your project. Whole-roll rounding may provide extra material already.
Your material estimate
Enter your ceiling area to calculate the whole rolls needed.
Delivery and installation excluded. This is a quantity and materials estimate, subject to the final quotation.
03 / Know what you are buying
The numbers that matter.
Roll size, coverage and material performance.
- Roll dimensions
- 5m x 1.2m
- Coverage per roll
- 6 m²
- Material R-value
- R3.38
- Ordering unit
- One whole roll
Dimensions and coverage are nominal. Material R-values are in m²·K/W; the complete roof and ceiling has a separate system R-value.
135mm Aerolite / The buying guide
A more comfortable home.
From the ceiling up.
Choose your insulation with the important details in front of you: thermal performance, coverage and the quantity your project needs.
135mm Aerolite insulation is supplied as a flexible glasswool blanket for the space above your ceiling. It slows heat transfer through this part of the building, helping you retain warmth in winter and limit heat entering from the roof space in summer.
01 / Everyday comfort
A practical improvement.
Season after season.
Good ceiling insulation starts with the right material and a careful fit. Here is what Aerolite Soft Touch brings to the ceiling space.
01 / Thermal comfort
Slow the movement of heat.
The blanket creates resistance to heat flow through the ceiling. Rooms can retain warmth more effectively in cold weather and gain less heat through the insulated ceiling during hot weather.
02 / Glasswool performance
Non-combustible material.
Isover identifies Aerolite Soft Touch as non-combustible glasswool. This describes the insulation material; the fire performance of a complete ceiling depends on all its components and how they are installed.
03 / Acoustic contribution
Absorb sound in the construction.
The glasswool can contribute to acoustic comfort within a suitable ceiling system. The result depends on the whole assembly and other sound paths, including windows, doors and walls.
Better insulation supports more efficient heating and cooling.
Reducing heat transfer can reduce the demand on heating or cooling equipment. Actual savings vary with the building, climate, thermostat settings and use of the rooms. A single savings percentage would not describe every home.
02 / Choose by performance
Why choose
135mm Aerolite insulation?
Match the insulation to the project’s thermal requirement. Then compare the cost of enough material to complete the ceiling.
Understand the R-value.
The published material R-value for this product is 3.38m²·K/W. R-value describes resistance to heat flow: a higher value means greater thermal resistance under the stated conditions. This is a product figure, rather than the total R-value of the roof and ceiling assembly.
When a project specifies 135mm Aerolite insulation, match the ordered product to that specification. Do not replace it with a thinner roll solely because the pack covers a larger area or has a lower price.
Plan around the ceiling you have.
For an existing home, establish the ceiling area to be insulated, the available roof access and the condition of any existing material. For a new ceiling, confirm when the insulation should be fitted and who is responsible for the installation.
For Cape Town and other Western Cape projects, the building’s location and complete construction should guide the specification. Have the required roof performance confirmed for the project; thickness alone does not certify compliance.
The product in practice
A blanket above
the finished ceiling.
The insulation belongs in the ceiling space. Your ceiling board remains the visible finish inside the room. Roof leaks, damaged boards and access problems should be dealt with before installation starts.
Check that the roof space has room for the specified thickness without squeezing the blanket into a shallow gap. Discuss any unusual ceiling construction with the person specifying or installing the material.
03 / Price it properly
One roll price.
A clearer project cost.
The most useful 135mm Aerolite insulation price is the cost of enough whole rolls for your ceiling.
Use the current product price above and the calculator to prepare a material estimate. Review the current price when you order, especially if you are working from an older quotation.
01
Price per roll
This is the cost of one whole roll. Check the VAT label displayed beside the price and confirm the quantity available for your order.
02
Price per square metre
Divide the roll price by 6. This gives a material cost per nominal square metre, useful when comparing coverage and prices on the same VAT basis.
03
Total material cost
Multiply the whole-roll quantity by the current roll price. Delivery and installation are separate items to confirm when arranging the order.
04 / Measure. Calculate. Order.
How many rolls
will you need?
Start with the actual ceiling area receiving insulation. The calculator uses 6m² per roll and rounds up to a complete roll.
Step 01
Measure the ceiling.
For a rectangular room, multiply length by width in metres. For several rooms, add their individual ceiling areas. Include passages and other spaces that will receive insulation.
Step 02
Choose an allowance.
Decide whether the layout needs extra material for cutting and fitting. The calculator offers 0%, 5% and 10%. Check the allowance with your installer where the layout is complicated.
Step 03
Round to whole rolls.
Divide the adjusted area by the coverage per roll. Round up rather than down. The result is a planning quantity to check against the job before placing the order.
A worked example
A 100m² ceiling.
A clear roll count.
With no allowance, 100 ÷ 6 gives 16.67 rolls. Round up to 17 rolls, supplying 102m² of nominal coverage. Adding 5% increases the order to 18 rolls.
| Allowance | Whole rolls | Coverage bought |
|---|---|---|
| 0% | 17 | 102m² |
| 5% | 18 | 108m² |
| 10% | 19 | 114m² |
Measure the surface being insulated.
For insulation above a flat ceiling, measure the ceiling footprint. If the design follows a roof slope, use the actual sloping surface area. Avoid using a property’s total advertised floor area without checking what it includes.
Keep the quantity with the enquiry.
Copy the calculator result and include your delivery suburb, required date and whether you need materials only or installation assistance. Clear measurements help make the quotation useful from the start.
05 / Get the fit right
Good preparation.
Better performance.
Installation affects how well the insulation performs. Follow the manufacturer’s instructions and the requirements for the roof space and its fittings.
Before installation
Keep the rolls dry and under cover. Resolve known leaks and damaged ceiling areas before fitting new material. Plan a safe access route; ceiling boards must not be treated as a walking surface.
When buying 135mm Aerolite insulation for an existing roof space, tell the installer about any material already there. Its condition, coverage and suitability affect the proposed work.
During and after fitting
Fit the blanket to the intended coverage and thickness. Avoid unnecessary gaps or compression. Electrical equipment, light fittings and ventilation need appropriate clearances and access.
Ask the installer to check the completed coverage and leave access points usable. Later electrical or roof repairs can disturb the blanket, so have affected areas checked and reinstated after that work.
Read Isover’s technical data sheet and installation guidance ↗
06 / Before you order
Your questions.
Clear answers.
The useful details about buying and fitting 135mm Aerolite insulation.
8 practical answers
How much does one roll cover?
A 135mm Aerolite Soft Touch roll measures 5m × 1.2m and covers a nominal 6m² before cutting and fitting. Confirm the specification on the supplied pack.
How many rolls do I need for 100m²?
At 6m² per roll, allow 17 whole rolls with no extra allowance. A 5% allowance takes the adjusted area to 105m² and requires 18 rolls. Choose the allowance to suit the installation layout.
What is the R-value of 135mm Aerolite?
The published material R-value is 3.38m²·K/W. The total roof-system R-value depends on the other components and construction details as well.
Is the price per roll or per square metre?
The ordering unit is one whole roll. The page also shows the equivalent material cost per square metre when a product price and coverage are available. Check the VAT label with the displayed price.
Can I put it over existing insulation?
Have the existing material assessed first. Its condition, current coverage and the required final specification determine whether an additional layer is appropriate. Resolve dampness or roof leaks before covering the area.
Will it make my ceiling soundproof?
It can contribute to sound absorption in a suitable construction, but it will not make a room soundproof on its own. Noise can also travel through walls, windows, doors and gaps.
Does the calculator include delivery and installation?
No. It estimates rolls and, where pricing is available, the material subtotal. Confirm delivery charges and any installation scope separately before ordering.
What if I do not know my ceiling area?
Measure each room’s length and width or use a dimensioned plan. Add the areas to be insulated. If the shape or access makes this difficult, ask for help checking the measurements before placing an order.
Make your next step simple
Ready to plan your rolls?
Measure your ceiling, calculate the quantity and review the current product price. Bring your measurements and delivery details together for a clearer order.
Product reference: Isover Aerolite Soft Touch specifications ↗. Checked 8 October 2026. Dimensions and coverage are nominal; confirm the current supplied product specification.
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