Glasswool ceiling insulation
100mm Aerolite Insulation
Plan your ceiling insulation with confidence. 100mm Aerolite insulation is a flexible glasswool blanket for ceiling applications. Each Soft Touch roll measures 6m × 1.2m, covers 7.2m² and provides a material R-value of 2.50m²·K/W.
Choose this thickness where it meets your project’s specification. Compare the current price per roll and per m², then use the calculator to work out your whole-roll quantity.
starts above the ceiling.
01 / Plan your order
Comfort, by the roll.
One product. Clear coverage. The quantity you need.
per roll
R71,63 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
- 6m x 1.2m
- Coverage per roll
- 7,2 m²
- Material R-value
- R2.5
- 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.
100mm Aerolite / The buying guide
Know your specification.
Plan every roll.
A well-planned insulation order brings together three things: the right thickness, an accurate ceiling area and enough material to finish the job.
100mm Aerolite insulation is a flexible glasswool blanket supplied in Soft Touch rolls. It is fitted above the ceiling to resist heat transfer through this part of the building. Start with the required thermal performance, then use the coverage and calculator on this page to prepare your order.
01 / Understand the material
Made for the space
above your ceiling.
Compare what the insulation does with what the building needs. These are the practical benefits of the Aerolite Soft Touch glasswool blanket.
01 / Thermal resistance
Manage heat flow.
Ceiling insulation slows heat moving through the insulated ceiling. It can help retain warmth during colder weather and reduce heat entering from a hot roof space, supporting a more comfortable indoor environment.
02 / Material choice
Non-combustible glasswool.
Isover identifies Aerolite Soft Touch as non-combustible. This is a property of the insulation material. A complete ceiling’s fire performance also depends on the boards, supporting structure, penetrations and installation details.
03 / Sound absorption
Contribute to acoustic comfort.
The fibrous blanket absorbs sound within a suitable construction. The overall result depends on the ceiling assembly and other routes that noise can follow through the building.
A roll that can be fitted to the ceiling space.
The flexible blanket is supplied compressed for transport and storage. During installation it is unpacked, cut and laid to suit the required coverage. The finished ceiling remains the visible surface below it.
Performance depends on the completed job.
Correct coverage and fit matter as much as the quantity delivered. Plan the work around roof access, services and ceiling details so the installer can fit the insulation at its intended thickness.
02 / Match the project
Is 100mm Aerolite
the right thickness?
Choose 100mm Aerolite insulation where its declared thermal resistance matches the specified construction. Roll coverage tells you how much to order; R-value helps you assess performance.
Start with the required thermal resistance.
The manufacturer lists a material R-value of 2.50m²·K/W for the 100mm product. That figure describes the blanket itself. The roof covering, ceiling and other components contribute to the performance of the complete assembly.
For a new build or renovation, keep the project’s insulation specification with the material order. Resolve any difference between the requested thickness and the product being supplied before installation begins.
Compare 100mm and 135mm correctly.
The 100mm roll is longer than the 135mm roll and covers more area, so a project may need fewer individual rolls. The products also have different material R-values. Fewer rolls does not mean the thinner product provides the same thermal resistance.
If your project calls for 135mm insulation, keep to that specification unless the person responsible for the design confirms a suitable alternative. A larger coverage figure should not be the reason for changing thickness.
Two sizes, clearly compared
Coverage and performance
answer different questions.
Use coverage to estimate the order. Use the required thermal performance to choose the product. Compare prices on the same VAT basis.
| Thickness | Coverage per roll | Material R-value |
|---|---|---|
| 100mm | 7.2m² | 2.50 |
| 135mm | 6m² | 3.38 |
Check suitability for your building.
The appropriate thickness depends on the building’s location and roof specification. For Cape Town and Western Cape projects, confirm the required performance before ordering. The figures above describe the insulation material; they do not certify a complete roof or ceiling system.
R-values are in m²·K/W. View Isover’s published Aerolite specifications ↗.
03 / Understand your material cost
Compare the roll.
Price the ceiling.
A useful 100mm Aerolite insulation price comparison accounts for both coverage and the number of whole rolls needed.
Review the current product price above, then calculate the material quantity for your ceiling. Keep your delivery location and any installation requirements with the enquiry so the final quotation can address the full scope.
01
The price of one roll
The product is ordered in whole rolls. Check the displayed price, VAT label and availability for the quantity you intend to buy.
02
The price per m²
Divide the roll price by 7.2 to find the equivalent material cost per nominal square metre. Compare this figure alongside the thickness and R-value.
03
The order subtotal
Multiply the rounded-up roll count by the current roll price. This material estimate excludes delivery and installation, which need to be confirmed separately.
04 / Make the measurements count
Work out your
100mm Aerolite roll quantity.
Measure the area receiving insulation, decide on a cutting allowance and round up to a whole roll. The calculator above handles the arithmetic.
Step 01
Measure each section.
For a rectangular ceiling, multiply the room length by its width in metres. Break an irregular ceiling into manageable rectangles and add their areas without counting overlapping sections twice.
Step 02
Review cutting and fitting.
Choose an allowance appropriate to the layout. Whole-roll rounding can already leave extra nominal coverage, but the shape and usefulness of offcuts affect how much can actually be reused.
Step 03
Calculate whole rolls.
Divide the adjusted ceiling area by 7.2 and round up. Keep the measurements with the resulting quantity so the installer or supplier can check the order before dispatch.
Example / A 100m² ceiling
14 rolls without
an extra allowance.
100 ÷ 7.2 = 13.89 rolls, rounded up to 14. Those rolls provide 100.8m² of nominal coverage. A 5% allowance increases the order to 15 rolls, supplying 108m².
| Allowance | Whole rolls | Coverage bought |
|---|---|---|
| 0% | 14 | 100.8m² |
| 5% | 15 | 108m² |
| 10% | 16 | 115.2m² |
One room or several rooms?
Use length and width for a single rectangular room. For several rooms, passages or separate ceiling areas, calculate each area first and enter the combined total. Exclude spaces that will not receive insulation.
A building’s advertised floor area may include a garage, patio or other areas outside the scope of the work. Check the actual ceiling footprint before using that figure to order 100mm Aerolite insulation.
Flat ceilings and sloping surfaces.
For a flat ceiling, use its plan area. If the specified insulation follows a slope, use that surface’s actual area. The calculator cannot identify roof geometry from a floor measurement.
If you are unsure about the layout, prepare a simple dimensioned sketch. Clear room measurements and a note about access are more useful than an unverified estimate of the whole property.
05 / Prepare for fitting
Plan the work.
Protect the performance.
A clear installation plan helps turn the correct material quantity into complete, consistent ceiling coverage.
Check the existing roof space.
Before fitting 100mm Aerolite insulation, identify leaks, damaged ceiling sections and any existing insulation that needs assessment. Confirm that the installer can reach the areas included in the order.
Keep delivered rolls dry and under cover. Arrange suitable access and support for the work; ceiling boards are not a safe walking surface. Follow the manufacturer’s handling instructions.
Agree on the installation scope.
Supply-only material and a completed installation are different orders. Confirm who is responsible for fitting, preparation, removal of unsuitable material and clearing packaging.
Fit the blanket to the specification.
Allow for the specified insulation thickness and avoid unnecessary compression. Follow the required clearances around light fittings and electrical equipment, and preserve any ventilation paths required by the roof design.
Inspect edges, access points and awkward areas before completing the job. Later roof repairs or electrical work can displace the blanket, so arrange for disturbed sections to be checked afterwards.
Assess before adding another layer.
Existing insulation may be uneven, damp, damaged or unsuitable to retain. Have its condition and the required final performance assessed before deciding whether a further layer is appropriate.
Read the Aerolite technical sheet and installation guidance ↗.
06 / Useful answers
Before you buy
100mm Aerolite insulation.
Check the specification, quantities and ordering details before completing your material plan.
8 practical answers
What size is a 100mm Aerolite roll?
The Soft Touch roll has nominal dimensions of 6m × 1.2m, giving 7.2m² of coverage before cutting and fitting. Confirm the specification on the supplied packaging.
How many rolls cover a 100m² ceiling?
Allow 14 whole rolls with no added allowance. With a 5% allowance, the adjusted area is 105m² and the quantity becomes 15 rolls. With a 10% allowance, it becomes 16 rolls.
What is the material R-value?
The published material R-value is 2.50m²·K/W. It describes the insulation blanket, while the complete roof and ceiling assembly has its own total thermal resistance.
Can 100mm replace specified 135mm Aerolite?
Not automatically. The two thicknesses have different thermal resistance and roll coverage. Keep the project’s specified product unless the person responsible for the design confirms a suitable change.
How do I calculate the price per square metre?
Divide the current roll price by 7.2. The ordering unit remains a whole roll, so the final material subtotal uses the rounded-up roll quantity. Compare prices using the same VAT basis.
Will the insulation stop all roof noise?
Glasswool can contribute to sound absorption in an appropriate construction. The overall result also depends on the ceiling, roof, gaps and other sound paths. The blanket alone does not create a soundproof room.
Can I fit it above an existing ceiling?
It may be suitable where the construction, access and thermal specification allow. Have the roof space and existing insulation assessed, and address leaks or ceiling damage before starting the installation.
What should I include in my order enquiry?
Include the 100mm product specification, measured ceiling area, calculated roll quantity, delivery suburb and required date. State whether you need materials only or installation assistance. Confirm delivery charges and availability separately.
Bring your material plan together
Your measurements.
Your roll quantity.
Use the calculator, check the current product price and keep the estimate with your delivery details. A clear specification makes the next step easier.
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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