Buying insulation online works well as long as the order is built from the right numbers. Send the areas, the framing or purlin centres, the R-value the job has to meet and the site access, and the quantities fall out of that. The two things that go wrong are ordering to the exact area with no waste allowance, and ordering a product that will not fit the depth available.
In short
- Six numbers get an order priced properly. Everything else is detail.
- Never order to the exact area. Add 5 to 10 per cent.
- Check the depth available before you pick an R-value.
- Roof insulation has to be on site before the roof is sheeted.
Most of our range can be ordered straight off the site. Where a job needs a take off, or the specification names something we should match, a short email does it. Either way the information needed is the same.
What to send us
| What we need | Why it matters |
|---|---|
| Areas in square metres | Measured on the roof plane for a pitched roof, not the floor plan |
| Framing or purlin centres | Decides batt width, and on a roof it decides the mesh lap |
| Depth available | Caps the thickness that will actually fit at full recovery |
| R-value or the energy report | The target comes from the report, not from preference |
| Building class and climate zone | Changes which code pathway and which products apply |
| Site address and access | Whether a pallet can be delivered and whether there is a forklift |
If you have the energy report or the specification schedule, send that instead of typing it out. We will read the numbers off it.
Choosing the right product
Three questions settle almost every order.
Where is it going? Under roof sheeting is blanket. Between ceiling joists is batts. Draped over battens for radiant heat and vapour is sarking or a membrane. The comparison is in blanket, sarking or batts.
What R-value? Take it from the report or specification. If the job is a shed or a workshop with no formal target, our guide to roofing blanket R-values covers the usual choices.
Does anything else have to be true? On commercial work the specification often names a fire classification, an acoustic system or a vapour class as well as the R-value. Meeting the thermal number alone is not enough, and a substitution that ignores those gets rejected on site.
Getting the quantities right
Area divided by the coverage printed on the pack or roll, plus a waste allowance, rounded up. Two things catch people out.
Coverage changes with R-value. A higher R-value means a thicker product and fewer units per pack, so the same ceiling needs far more packs at R6.0 than at R3.5. Never estimate off the last job.
A pitched roof is bigger than its footprint. Multiply the plan area by roughly 1.02 at 10 degrees, 1.08 at 22.5 degrees and 1.16 at 30 degrees.
The full method, with worked examples for packs and rolls, is in how much insulation do I need.
Delivery and site access
Insulation is light but bulky. That changes what a delivery needs.
- Tell us if it is a residential address. A pallet on a semi trailer and a suburban driveway do not mix.
- Say whether there is a forklift. Otherwise plan for hand unload, which takes longer and needs someone there.
- Have somewhere dry to put it. Glasswool that gets rained on before it goes up is a problem you then build into the roof.
- Stage large orders. If the site cannot hold the whole job, we can split the delivery to the program.
When to order
The roof package is the one with a hard deadline. Blanket, mesh and spacers go in under the sheeting, so they have to be on site before the roof is closed. Miss that and the only way back is lifting sheets.
Everything else is more forgiving. Wall and ceiling batts go in after lock up and can follow the build.
| Stage | What should already be ordered |
|---|---|
| Frame up | Roof package: mesh, blanket, spacers, thermal break |
| Roof sheeting | Nothing left to order. Last chance for anything under the sheets. |
| Lock up | Wall batts and any acoustic systems |
| Before lining | Ceiling batts |
What to check on arrival
- Product and R-value on the label match what the specification names, including the facing type
- Pack or roll count matches the docket
- Nothing is wet or torn
- Keep the product data sheets. The certifier compares the built work against them.
Ordering mistakes that cost a day
- Ordering the exact area. Offcuts, damaged packs and one awkward corner all come out of the same allowance. Add 5 to 10 per cent.
- Wrong batt width. 430 mm suits 450 mm centres, 580 mm suits 600 mm. Measure the framing in a few places before ordering.
- Buying an R-value that will not fit. Check the depth first. Compressing a thick batt into a shallow space removes the air that does the insulating.
- Forgetting the accessories. Roll systems need tape for the laps. Commercial roofs need mesh and spacers. They belong on the same order.
- Leaving the roof package to the last week. It is the one item with a fixed window.
Send the areas and the R-values and we will do the take off. You will get quantities, pack counts and a delivered price, and you can order the whole lot online.
Get in touch, or browse roofing blankets, ceiling, wall and commercial insulation.
Frequently asked questions
Can I buy insulation online in Australia?
Yes. Our range is available to order online with delivery across Australia. For a job that needs a take off, send the areas and the R-values and we will work out quantities first.
What information do you need to quote?
Areas in square metres, framing or purlin centres, the depth available, the R-value or the energy report, the building class and climate zone, and the site address with access details.
Can you work out quantities for me?
Yes. Send the plans or the measured areas with the framing centres and we will come back with pack and roll counts including a waste allowance.
How much extra should I order?
5 per cent on a simple rectangular ceiling, 10 per cent on a typical house, and 10 to 15 per cent where the plan is cut up or the framing centres are inconsistent.
Do you deliver to residential addresses?
Yes, but tell us at the order stage. A pallet delivery needs different access to a small parcel, and it changes how the freight is booked.
Do I need a forklift on site?
For pallet quantities it makes the delivery much faster. If there is no forklift, say so and we will plan for a hand unload, which needs someone available to receive it.
When do I need to order roof insulation?
Before the roof is sheeted. Blanket, mesh and spacers sit under the sheeting, so once the roof is closed the only way to add them is to lift sheets.
What if the delivered product is not what the specification named?
Check the label against the specification on arrival, including the facing type and any fire classification. Tell us straight away rather than installing it, because a substitution that was not approved can be rejected by the certifier.
Sources
- NCC 2022 Housing Provisions, clause 13.2.2 Thermal construction, general
- Product coverage figures from the AWBM catalogue, taken from the manufacturers' pack data
General information. Access, freight and lead times vary by site and order size, so treat the checklists above as a starting point rather than a quote.