FAQ · The two questions people worry about most
Does cellulose insulation cause mould?
Loose-fill can settle. But the right install density controls it, so we pump to a specified settled density that holds. And cellulose doesn’t cause mould: full contact removes the cold gap where condensation forms.
These are the two worries I hear most once people get past “is it safe?”. They’ve read that loose-fill slumps, and they’ve seen mould creep across a ceiling. Both have a real answer, and I’ll give you the straight version of each, with the Australian Government’s own sources behind it, not a salesman’s “never happens.”
Real reviews, real jobs
What our customers say
Genuine Google & hipages reviews from Comfort Zone customers across SE Queensland.
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Angela M.
SE Queensland
“The fact that I can't even tell it's 6 degrees outside when I wake up in the morning speaks for itself. Have wasted so much money attempting to heat and cool an uninsulated home. Worth every $.”
- Phipages
P Peter
Alstonvale, 2024
“Connected with Comfort Zone Insulation and would recommend them”
- J
Jessa B.
Brisbane
“It dropped about 4 degrees straight away, and we added another 3 with the second job. I appreciate Peter's honesty, and the team showed pictures before and after.”
- Nhipages
Nola M
Birtinya, 2024
“They were courteous and competent.”
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Iain V-B.
Brisbane
“Quick and polite service. Great follow-up advice and photos sent for our records. Above and beyond what we expected. Would highly recommend.”
- Jhipages
Jennifer's E
Upper Caboolture, 2024
“Excellent customer service. Highly recommended. Has a profound knowledge of insulation products and has the best interest of his customer.”
- G
Gerry S
Fitzgibbon, 2023
“I used Comfort Zone and they have a done an excellent job.”
- Jhipages
Jennifer
Upper Caboolture, 2024
“Excellent customer service. Highly recommend. Has a profound knowledge of insulation products and has the customer best interest.”
- J
Jung K
Riverhills, 2023
“An experienced family operation. Highly recommend. Thank you for the great job!”
- Dhipages
Diane A
Ormeau, 2024
“Peter and crew did a great job I would definitely recommend them”
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David H
Sunshine Coast, 2021
“Completed the job as quoted and to a high standard. Great personal service. Would highly recommend Comfort Zone for ceiling installation work.”
- Thipages
Timea
Highland Park, 2023
“I was extremely satisfied with the service they provided. They gave a very thourough explanation of the materials used, the way the work will be carried out and the price I had to pay was the exact amount quoted, no hidden costs included. They arrived on time, well prepared and workwas carried out exactly how they said it would be, they were super efficient, well prepared and were kind enough to even clean up after themselves. The services they provided was second to none! I don't hesitate to recommend them for any insulation job!”
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Benjamin H
Carseldine, 2019
“Very good explanation about their works. Advice of existing problems with the roof. Clean work. Very professional.”
- Mhipages
Mark
Pottsville, 2017
“Michelle, we are done - Peter from comfort zone insulation was very helpful. very honest with his recommendations - in fact he told me that the product my daughter had if installed correctly was superb. Thanks Peter you are a champion and i would recommend you to any person that was wanting professional advice and old school service.”
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Ian G
Burnside, 2019
“Good information, communication and professionalism.”
- Jhipages
Jessica
Pottsville, 2016
“This business offers a fantastic product that other businesses did not. Pump in ceiling insulation. Knowledge of the industry second to none.”
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Danny D
Boondall, 2018
“He explained everything he was going to do and the different types of insulation they used. He talked through the different options but made a recommendation for the one most people use, which is the one I chose. He was very understanding towards what I needed and not about himself.”
- Jhipages
Jack
Pottsville, 2023
“Excellent communication and informative. Professional.”
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Graham R
Riverhills, 2018
“Comfort Zone. Turned up ahead of time, completed in about 2 hours, cleaned up. All good. Very motivated installation team.”
- Thipages
Tony P
Redland Bay, 2023
“Very knowledgeable about insulation”
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Alex B
West Ipswich, 2018
“Fast, friendly, efficient.”
- Shipages
Steve
Redland Bay, 2017
“Excellent job and reasonable price.”
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Luke D
Mcdowall, 2017
“Peter did a good job. It was a quick and clean service. I'm happy to recommend!”
- Bhipages
Bruce H
Kuluin, 2023
“Prompt and efficient quoting.”
- B
Brendon
Brays Creek, 2016
“Peter supplied and installed roof insulation for me. He was very informative and provided good advice.”
- Ghipages
Gerry S
Fitzgibbon, 2023
“I used Comfort Zone and they have a done an excellent job.”
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Trevor G
Brookside Centre, 2016
“Excellent tradesmen from Comfort Zone Insulation. They were punctual and cleaned up after. Highly recommended.”
- Thipages
Tamara
Underwood, 2023
“Peter is honest, hard-working and came on time. Knew excally what he was talking about and answered my questions. Would 100% recommend”
- J
John G
Beaudesert, 2019
“Peter is an honest person who provided me with the information I wanted then performed a good job with great results for the benefit of myself and my family.”
- Shipages
Sterling G
Ashgrove, 2023
“Comfort Zone were very knowledge with great communication and follow up”
- Ghipages
Graham R
Riverhills, 2018
“Comfort Zone. Turned up ahead of time completed in +- 2 hours cleaned. All good. Very motivated installation team”
- Jhipages
Jung K
Riverhills, 2023
“An experienced family operation. Highly recommend. Thank you for the great job!”
- Khipages
Kathy A
North Lakes, 2023
“We connected with Peter through HiPages and he was prompt, professional and even came back after the job was complete to assist with a question we had. We would highly recommend Peter for further insulation works.”
- Dhipages
David H
Sunshine Coast, 2021
“Completed the job as quoted and to a high standard. Great personal service. Would highly recommend Comfort Zone for ceiling installationn work.”
- Shipages
Sue H
Sunshine Coast, 2021
“Incredible customer service”
- Ehipages
Eileen C
Cedar Vale, 2021
“Quality work, good customer service, prompt”
- Chipages
Craig M
Woody Point, 2021
“Called within 5 minutes of request. Very knowledgeable and explained job in great detail, provide great advice in prior preparation for works required. Very friendly and helpful.”
- Jhipages
Jenny C
Plainland, 2021
“Although I did not hire Peter I was impressed with the initial contact and the knowledge he was willing to impart. I was treated with respect which I appreciated. I would have hired but I received a lower quote.”
- Qhipages
Quinton
Coomera, 2020
“Professional installation without any short cuts. True to their word with high integrity. Response from Comfort Zone Insulation”
- Ghipages
Gary P
West Kempsey, 2020
“Came & Gave a free quote”
Settling
Density controls settling, and the settling stories come from under-filled jobs.
Here’s the plain fact, straight from the Australian Government: loose-fill insulation does settle a little, and that’s exactly why it has to be installed properly. The CSIRO says loose-fill cellulose may settle over time and that allowance should be made during installation, and that correct installation requires an appropriately high density that the installer should state. That last bit is the whole game. Pump it in light and airy and it looks thick on day one, then slumps. That’s where the settling horror stories come from. Pump it to its proper settled density and it’s already at the depth it will hold.
So the settling people hear about isn’t a cellulose problem. It’s an under-filled-job problem. A cowboy blows it in light so the bags go further and the quote looks cheaper, the customer never climbs up to check, and a year later it’s slumped and there are gaps. We pump to a specified density, so what goes in is what stays. The Australian Government tells you the single best way to protect yourself, and it’s the question to put to every quote you get: yourhome.gov.au says to ask your contractor for a guaranteed “settled R-value” , not a fluffed-up day-one number.
What you actually rely on
I lead with the guarantee, not a “never settles.”
Nobody can promise you a material that never moves. What I’ll give you instead is a written commitment. In more than 6,000 jobs I’ve never seen our correctly-installed cellulose settle, blow around or open up gaps. The only time I’ve pulled it out is when someone was replacing their ceilings. The cellulose we pumped 10+ years ago still looks new.
That’s lived experience, and it’s worth telling you. But the thing you actually rely on is the paperwork: our cellulose carries a transferable Comfort Zone® Life-of-House Guarantee that passes to the next owner if you sell, and we install to the product’s specified settled density. So the answer to “will it slump?” isn’t a salesman’s promise. It’s a settled R-value installed to spec, in writing.
Comfort Zone insulation.team
Family-owned insulation manufacturer, making comfy homes since 1986
Mould
Mould grows on the cold gaps. Full contact takes the cold spot away.
Cellulose doesn’t kill mould. What it does is remove the place mould likes to grow. Mould on a ceiling comes from condensation, and condensation forms on cold spots. Where insulation is missing or gappy, that strip of ceiling stays cold while the rest is warm. Warm, moist house air hits the cold strip, condenses, and you get the mould. It’s why you sometimes see mould in dead-straight lines on a ceiling: those lines map the gaps between badly-laid batts.
This isn’t just my theory. The Australian Government joins the dots directly. The yourhome guide says thermal bridges, the cold pathways where insulation is missing, lead to condensation problems, and the ABCB’s Condensation in Buildings Handbook warns that condensation in concealed spaces breeds fungus and mould. Pumped cellulose covers the whole ceiling with full contact and no gaps, so there’s no cold strip for the moisture to condense on. That’s the mechanism. A thermal-gap fix, not a mould killer.
Comfort Zone insulation.team
Family-owned insulation manufacturer, making comfy homes since 1986
And if the roof leaks
Cellulose pins a leak to one spot. Batts hide it and spread it.
Here’s a difference most people don’t know about until they’ve had a leak. Cellulose is hygroscopic. It’s a paper fibre, so it absorbs a bit of incidental moisture and then dries back out. Fibreglass and mineral-wool batts are hydrophobic, so when water comes through a roof it runs straight underneath them and spreads across the whole ceiling, often hiding the leak until the plasterboard finally sags. With cellulose, a small leak tends to stay in one spot and leave a discoloured patch, which actually helps us find where the roof is leaking.
I’ll be straight about the limits. The government’s guidance is that any insulation performs poorly if it gets wet: cellulose doesn’t waterproof your roof and it won’t fix a leak. A serious or ongoing leak needs the roof repaired, and badly wet insulation of any kind has to be assessed. What cellulose does do is handle the odd bit of incidental moisture and localise the damage, instead of letting water run silently across your whole ceiling the way it does under batts.
Comfort Zone insulation.team
Family-owned insulation manufacturer, making comfy homes since 1986
One place we don’t use cellulose
Under the floor we use polyester, not cellulose.
Pumped cellulose is the right product for a ceiling, where it sits as a blanket on top of the plaster. But it’s the wrong product for a crawlspace. There’s nothing under a suspended floor to hold a loose fibre up. So for underfloor we fit polyester batts, friction-fitted up between the joists. Polyester is locally made, non-itchy, doesn’t carry the glass-fibre handling warnings, and in 30-odd years I’ve never seen a polyester batt settle the way fibreglass does.
One more thing worth knowing: in a warm climate, underfloor insulation isn’t always worth doing. The Sustainability Victoria guidance notes that insulating a suspended floor can actually add to a home’s summer cooling load in some warmer climates, so I’ll tell you straight whether your floor is worth the money before you spend it.
More on settling, mould and moisture
Does cellulose insulation settle over time?+
Any loose-fill insulation can settle a little; the Australian Government's CSIRO says so plainly, and the reason it matters is that you have to allow for it when you install. The whole game is install density. We pump cellulose in to a specified settled density, so it's already packed to the depth it'll hold rather than fluffed up to look thick on day one. The settling horror stories people hear about loose-fill come from under-filled jobs, a cowboy who blows it in light and airy so the bags go further, then it slumps and opens gaps. Pack it to the right density and it stays put. yourhome.gov.au tells you exactly how to protect yourself: ask your contractor for a guaranteed settled R-value, not a day-one number. That's what we install to, and it's backed by our transferable Life-of-House Guarantee.
Does cellulose insulation cause mould?+
No, and done right it actually helps prevent the surface mould you get on a ceiling. Mould on a ceiling comes from condensation, and condensation forms on cold spots. The Australian Government ties this together directly: yourhome.gov.au says thermal bridges (the cold gaps where insulation is missing) lead to condensation problems, and the ABCB's Condensation in Buildings Handbook warns that condensation in concealed spaces breeds fungus and mould. Pumped cellulose covers the whole ceiling with full contact and no gaps, so you don't get the cold strips where warm, moist house air hits the plaster and condenses, which is why you sometimes see mould in straight lines that map the gaps between batts. So it's a thermal-gap mechanism, not a mould killer. It doesn't kill mould; removing the cold gaps removes the place mould likes to grow.
What happens to cellulose if my roof leaks?+
Cellulose is hygroscopic; it's a paper fibre, so it absorbs incidental moisture and then dries back out. Batts are hydrophobic, so when water comes through a roof it runs underneath and spreads across the whole ceiling, often hiding the leak until the plasterboard sags. With cellulose a small leak tends to stay localised in one spot and leaves a discoloured patch, which actually helps us find where the roof is leaking. There are limits: cellulose doesn't waterproof your roof and it won't fix a leak; a serious or ongoing leak needs the roof repaired, and badly wet insulation of any kind has to be assessed. What it does do is handle the odd bit of incidental moisture and pin the damage to one place instead of letting it run everywhere.
Why do you use polyester batts under the floor instead of cellulose?+
Because pumped cellulose is the wrong product for a crawlspace. It's a loose fibre that needs a ceiling to sit on top of, and there's nothing to hold it up under a suspended floor. For underfloor we fit polyester batts, friction-fitted up between the joists and held in place. Polyester is locally made, non-itchy, doesn't carry the glass-fibre handling warnings, and in 30-odd years I've never seen a polyester batt settle the way fibreglass does. One caveat: in a warm climate underfloor insulation isn't always worth doing. Australian guidance notes it can even add to summer cooling load in some homes, so I'll tell you straight whether your floor is worth doing before you spend the money on it.
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