01/12/2025
🔥 Yeah. Nah… Why the “Garden Hose on the Roof” Won’t Save You!
During bad fire weather days, when large bushfires threaten, we often see the same image on the TV news: someone standing on their roof in shorts and a t-shirt, clutching a garden hose while smoke and fire billow behind them. (Sigh)
Besides all the “leave early” messaging—which, at times (especially on Facebook), can feel like banging our heads against a brick wall 😅—we want you to understand why an image like this makes us shake our heads.
You just have to look at the maths. (Note: In the fire services, the "nozzle" at the end of the hose is called a Branch).
💧 THE BATTLE OF THE FLOW RATES
Here is the difference between what you are holding and what we use to fight bushfires:
🟢 Garden Hose: approx. 15–25 L/min (Standard domestic flow)
🔵 CFA Medium Branch: approx. max flow rate. 230 L/min
🟣 CFA Large Branch (38mm): approx. max flow rate. 475 L/min
⚠️ The Reality Gap
The most common tool our crews use to fight bushfires is the 38mm hose and branch off a tanker. Depending on the branch used, this equipment can deliver a max flow rate between 230 and 475 litres of water per minute.
That means the equipment and just one hose line off the back of our trucks can put out roughly 20 times—or more—the amount of water your garden hose can. And we can run multiple hoses! 🚒
🔥 But here is the scary part:
On Extreme or Catastrophic fire danger days, even our 38mm attack lines and larger branches cannot—and will not—stop a wind-driven fire storm once it has taken hold. The spotting, rapid spread, and intense radiant heat are simply overwhelming.
Think about it: if trained firefighters with a fire truck, hoses (likely multiple hoses), and a specialized branch(es) that can spray up to 475 litres of water per minute (max flow) each won't be able to stop or even likely defend against fires like Ash Wednesday or Black Saturday (and often it is too dangerous for us to even try), a garden hose dribbling 20 litres out the end does not stand a chance.
It cannot cool the air, it cannot reach the flames or spot fires, and it offers zero protection from the radiant heat (just like the clothing in this image). In fact, what little water does come out will likely evaporate before it does anything useful.
Spot fires from ember attack can ignite all around you, escape routes are likely to be cut off, and chances are you’ll be trapped—fighting for your life, not to save your home.
🚰 The Other Hidden Danger: Pressure Drop
When fire hits an area with mains water, two things happen: residents instinctively turn on taps and hoses, and fire trucks begin drawing large volumes from the hydrants.
Mains pressure plummets. Your garden hose flow can drop from "weak" to "useless" in seconds—right when the fire front arrives.
🧯 The Bottom Line:
Standing on a roof with a hose isn’t a strategy—it’s taking a butter knife to a gunfight.
🚗💨 Be Smart, Be Alive. Leave early and live on days of Extreme or Catastrophic fire danger.
We also suggest you go back and read some of our earlier posts about planning, preparing, acting and surviving this summer!