Insulation waste · what actually happens to it
What happens to old fibreglass batts? Every batt job leaves a pile of plastic behind.
I’m Peter Johnson, a Brisbane insulation contractor since 1986. Watch the video below and you’ll see exactly what a batt removal job leaves behind: bagged fibreglass batts carted off site with nothing to do with them but dump them. Cellulose Fibre Insulation runs a different path from the bag going in to the bag coming back out. This page walks through why.
The plastic waste left behind by a fibreglass batt job
The plastic bags carted off site and dumped from a batt job — nothing you can do with them, unlike our reusable cellulose bags.
Read the transcript
G'day guys, Peter here from Comfort Zone Insulation. I just wanted to show you something. I mean, when we sell cellulose fibre insulation, it all comes in reusable bags and we empty them out in the machine, pump it into your roof and then bring the bags back and refill them every time. So, might refill them a thousand times, I don't know. But when you buy batts, they all come in plastic bags and this is just our two trailers here, so this one here and someone over there. And we just fill those up with these plastic bags that are left over from batts. So that's a whole bag full of bags there and I mean there's some other rubbish in there from sites and things, fibreglass batts, they all come in those wrappers, you know, here's some oil foil out of roofs. So that's, you know, those are the Earthwool ones, they're particularly hard plastic. So all of this ends up in landfill. Just bags full of bags, you know. And out of one job, this whole bag here full, you know, like an average size house that would have two of those bags full of plastic. So that's about, you know, it's probably about two or three weeks worth of rubbish from us in that trailer there. But we don't do a lot of batt jobs, that's just a couple of batt jobs a week, you know. Anyway, alright, so that's another reason why the cellulose fibre is a lot better product to use and a lot more environmentally friendly. There's just no rubbish left over and, you know, the product's guaranteed for life against fire and vermin and it's pumped in so there's no gaps. It's a fantastic product and it uses one-twentieth of the energy to produce as what fibreglass does in the first place and then there's no rubbish left over when you're done. So, and if you ever want to, you know, pull it out or whatever, we can vacuum it out in 20 years' time. Like I've had jobs where, you know, 20 years later we can vacuum it out and pump it into another job, you know. It's just such a good product whereas all the fibreglass that you pull out after it's been in a roof for 20 years, there's no way in the world that's going back into another job and it's just rubbish. Alright, so I'll leave that with you.
What a batt removal job actually leaves behind
Old fibreglass batts don’t come out clean. They come out as a pile of bagged plastic.
Pull old fibreglass batts out of a roof and they’re rolled up and bagged for the trip down the ladder. Loose glass fibre floating around a work site isn’t something you leave open to the air. Every one of those bags is plastic. Every one of them is heading to the same place: off site and into general waste. There’s no second use for a bag of degraded fibreglass batts, no program I’ve found that takes them back, and no way to send them anywhere except the tip.
That’s not a one-off on a bad job. It’s every fibreglass batt removal I’ve ever done, in forty years on roofs.
A skip bin filled with old pink and yellow fibreglass batts pulled out during a removal job — Strathpine. Every bag in a bin like this ends the same way, at the tip.
Two lots of plastic, not one
The plastic problem starts on install day, not just on removal day.
Fibreglass batts arrive on site compressed and wrapped in plastic packaging, one pack at a time. Each pack gets torn open and the wrap gets binned as the batts go in, so a full house of batts is a full house of plastic wrap in the skip before a single batt has even settled. Years later, when those batts are pulled out again, they get bagged in plastic a second time for the trip to the tip.
I’ve spent forty years installing and removing insulation across South East Queensland and Northern NSW. I’ve never been able to find a facility that takes either lot of plastic back, so on my jobs both trips end at general waste. That’s the state of it as far as I’ve been able to establish, not a worst-case example. If there’s a take-back program running that I haven’t found, tell me and I’ll use it.
Plastic-wrapped rolls of new glasswool batts stacked in a shipping container. Every one of those wraps comes off and goes in the bin before the batt itself ever reaches a roof.
Bag in, bag out, same bag
Our cellulose fibre comes in reusable bags, not single-trip plastic.
Cellulose Fibre Insulation is delivered to a job in bags that are built to be refilled and run through the factory again, rather than torn open once and thrown away. The same bag gets reused hundreds of times over many years before it’s retired, so a house full of cellulose fibre doesn’t leave a house full of plastic wrap in the skip the way a house full of batts does.
We can say that with confidence because we manufacture Cellulose Fibre Insulation ourselves at our own factory in Tiaro. The bags come back to us, get refilled, and go back out on the next job.
Where the fibre itself comes from
It’s made from recycled paper before it’s even bagged the first time.
Fibreglass batts are made by super-heating spun rock or glass fibre in a furnace. Cellulose Fibre Insulation is made by pulping and shredding recycled paper, usually post-consumer waste newsprint that would otherwise be heading to landfill itself — about 80% of our product by weight, our own figure for what actually goes through the Tiaro factory. A peer-reviewed study puts the manufacturing energy at 0.94 to 3.3 MJ per kilogram for cellulose fibre against 10.8 to 45 MJ per kilogram for commercial thermal insulation — about 90% less at the midpoint of those two ranges. Frontiers in Built Environment (2023) — “Energy incorporated per kilogram of cellulose is between 0.94 and 3.3 MJ/kg, a reduced range of values compared to commercial thermal insulation that is between 10.8 and up to 45 MJ/kg” (citing Lopez Hurtado et al. 2016 and Pal et al. 2021) — the recycled-paper % above is CPA's own figure, not from this paper ↗
The Australian Government’s own Your Home guide runs its own numbers. They point the same way: it puts glasswool insulation at 57.5 MJ per kilogram in its embodied-energy table for common building materials. That’s higher than the top of the commercial range in the study above. It’s a government figure for the exact product a batt job puts in your roof. yourhome.gov.au — Embodied energy of common building materials: “Glasswool insulation 57.5” MJ/kg ↗ Your Home does not publish a cellulose fibre figure of its own, so the two documents sit beside each other rather than confirming one another.
Recycled paper feedstock, low manufacturing energy, and a bag that goes back to the factory instead of the tip. That’s the environmental case for Cellulose Fibre Insulation. Every part of it is something we can point to a document or a photo for.
The other end of the product’s life
When cellulose fibre comes back out of a roof, it goes back to the factory, not the tip.
Old Cellulose Fibre Insulation is vacuumed out rather than ripped out by hand. From there it can be brought back to our own factory in Tiaro and remanufactured into new bags, ready to go back out on the next job. That’s only possible because we manufacture Cellulose Fibre Insulation ourselves and control both ends of the process, from the recycled paper going in to the vacuum hose coming out.
A batt company that buys its product in from an overseas manufacturer has no equivalent option. Once a batt is bagged for the tip, that’s the end of it.
Both jobs, side by side
The same removal job, two different waste streams.
This is specifically about the packaging and end-of-life waste each product leaves behind, not R-value or install quality.
| Stage | Fibreglass batts | Cellulose Fibre Insulation |
|---|---|---|
| Packaging on delivery | Compressed plastic wrap per pack, torn open and binned | Reusable bag, refilled and sent back out again |
| Feedstock | Newly spun rock or glass fibre | Recycled paper, pulped and shredded at our Tiaro factory |
| Removal from the roof | Rolled up and bagged in plastic by hand | Vacuumed out |
| Where it ends up | General waste, no take-back program found | Back to our Tiaro factory, remanufactured into new bags |
Common questions
Fibreglass batt waste, the questions I get.
What actually happens to old fibreglass batts when they come out of a roof?+
We roll them up, bag the debris in plastic and cart the bags off site to the tip. That's true whether the batts are being replaced because they've settled and gapped or pulled out because a house is having its insulation redone properly. Once they're bagged there's nothing further to do with them — they go into general waste, same as any other bagged rubbish off a job site.
Where does the plastic from a batt job actually end up?+
There are two lots of plastic on a typical batt job. Fibreglass batts arrive wrapped and compressed in plastic packaging, which gets torn open and binned as each pack is laid. Then, when old batts are removed years later, the debris gets bagged in plastic again to cart off site. In my own experience across South East Queensland and Northern NSW, I've never been able to find anywhere that takes either lot back, so on my jobs both trips end at general waste.
Is Cellulose Fibre Insulation more environmentally friendly than fibreglass batts?+
On the two things I can actually stand behind, yes. Our Cellulose Fibre Insulation comes in reusable bags that get refilled and run through the factory again and again instead of being thrown out after one job, so there's no waste plastic on the way in. And the fibre itself starts life as recycled paper rather than newly quarried rock or melted glass, with a peer-reviewed manufacturing-energy figure of 0.94 to 3.3 MJ per kilogram against 10.8 to 45 MJ per kilogram for commercial thermal insulation — about 90% less at the midpoint of those two ranges.
What happens to Cellulose Fibre Insulation when it's removed from a roof?+
It gets vacuumed out rather than ripped out by hand, then brought back to our own factory in Tiaro and remanufactured into new bags. That's a genuinely different end point to a batt job's plastic bags heading to the tip. It's only possible because we manufacture the product ourselves rather than buying it in from an overseas supplier with no way to take it back.
Does the same waste problem apply to loose-pumped fibreglass, like Knauf Jetmax?+
It arrives in bags rather than compressed packs, so the packaging story is a little different. I haven't found a program that takes those bags back for reuse either. The comparison on this page is specifically about fibreglass batts, since that's the removal job that generates the pile of plastic in the video above.
Figures on this page are read from the cited peer-reviewed and government sources, current as of July 2026. Everything else on this page describes what we’ve personally seen and done on real jobs. This page is general information, not an environmental compliance claim about any specific disposal or recycling facility.
Do you have fibreglass batts in your roof now? We can quote to remove them or fix your insulation.
If you’d rather your next insulation job didn’t leave a pile of plastic behind, the two products that don’t work that way are Cellulose Fibre Insulation and polyester batts. Get a quote and we’ll talk you through both.
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Send us your address and roof type for a fixed-price quote within 48 hours for most houses, removing old fibreglass or pumping in Cellulose Fibre Insulation or polyester from scratch. Servicing Brisbane, SE QLD and Northern NSW.
Peter Johnson
Owner / installer · Comfort Zone Insulation Team® · Since 1986