Rats in your insulation? The $1,000 Rodent Reward.

No insulation is fully rat-proof, and anyone who tells you otherwise is having you on; a determined rat will get into a roof cavity regardless of what's up there. What changes is whether they can make a home once they're in. Soft batts are loose enough that mice push them up and tunnel underneath, so they shred them into nesting material and foul them. Pumped cellulose is a different proposition: it goes in as a dense, packed blanket with no loose lift to it, so there's nothing soft to fluff into a cosy nest. On top of that, cellulose is treated with borate, which means the insects rats feed on can't survive in it, and after more than 6,000 roofs I've pumped, I've never pulled a rat nest out of one. That's field experience, not a lab promise: I won't tell you a rat can never get in your roof, but I'll tell you what they do and don't do once they're there.

Two reasons, and I see them in real roofs every week. First, it's physical. A fibreglass or polyester batt sits loose between the joists, so a rat or mouse can lift it, burrow under it and shred it into a warm, hidden nest. Dense-packed cellulose has no give; it's pumped to a settled density and lays as one solid blanket, so there's nothing to tunnel into. Second, it's the borate. Cellulose is treated with a borax-based mineral salt, which means the insects rats and mice feed on up there can't survive in it. No insects means no easy food, and no food means a rat has little reason to set up house. I pull matted, urine-soaked nests out of batt roofs constantly, and in thousands of cellulose roofs, I just don't find them.

It's a challenge, not a bounty; we're not asking anyone to go hunting in roofs. We're so confident rodents won't nest in our cellulose that we back it with a reward: if you find evidence of a rodent nest built in a roof we've pumped with Comfort Zone cellulose, contact us (head office, not your local installer) and we'll arrange an impartial inspection, fix the affected cellulose at no cost, and pay the home owner a $1,000 reward. It covers our loose-fill cellulose only, it's one reward per home, it's paid to the property owner rather than whoever found it, and it's transferable with the house. In all our years insulating we've never once seen a rat nest in our cellulose, which is exactly why we can stand behind it with a reward. The full terms are on our Rodent Reward page.

Yes, but we'll deal with what's already there first. If your old batts are nested in, shredded or fouled with rodent urine and droppings, we don't just blow new insulation over the top of a mess. That traps the smell and the muck in your ceiling. Every job is photographed to the same system, so any existing vermin damage is photographed and flagged to you before we do anything, and you can decide whether the old material should come out. We can vacuum out contaminated insulation and start clean. And while you've got the roof open is the right time to chase up any obvious entry points, insulation isn't pest control, so seal the gaps a rat is using to get in, then put cellulose down so it stays a clean, dense blanket rather than a nesting site.