7 Signs Your Whirly Bird Needs Replacing

A dead whirly bird looks exactly like a working one from the footpath. That is the problem — plenty of Perth homes have roof vents that stopped moving air years ago, and nobody noticed because the shape is still up there.

Here is what to actually look for.

1. It doesn't spin in a decent breeze

The clearest sign. Go out at 4pm on a summer afternoon when the sea breeze is up and look at the roof. Every turbine should be turning. One sitting dead still has seized bearings and is doing precisely nothing.

2. It squeals, grinds or rattles

Noise means the bearings are on the way out. A squeal that comes and goes with wind strength is a unit in its final season. Lubrication occasionally buys a few months, but on a $350 replacement it is rarely worth the ladder trip twice.

3. Rust streaks on the roof below it

Orange staining running down tiles or sheets from the base of the vent means the unit itself is corroding. Coastal suburbs see this early — salt in the sea breeze attacks the housing and any non-marine-grade fastener. Once rust has started, the structure is compromised even if it still turns.

4. Storm damage

A Perth winter front, or a branch off a gum, will dent a dome or bend the vanes. A bent turbine spins unevenly, wears its bearings out fast, and can vibrate the flashing loose. Worth replacing rather than living with.

5. Visible gaps around the flashing

Get someone to look from a safe vantage point — or check the ceiling below after heavy rain. Lifted, cracked or silicone-patched flashing is a leak waiting to happen. If the original installer bedded the unit in sealant rather than flashing it properly, the sealant will eventually let go.

6. Your roof feels hotter than it used to

A gradual change is easy to miss, but if the upstairs has been getting worse over a few summers and nothing else has changed, check the roof vents before you blame the insulation or the aircon.

7. It's over 12–15 years old

Quality units last 10–15 years inland and less near the coast. If yours came with the house and the house is 20 years old, it has done its time regardless of how it looks.

What a replacement involves

Because the roof already has a penetration in the right place, a swap is quick — 30–45 minutes per unit. The old unit and its tired flashing come off, the surrounding tiles or sheets and the sarking get checked, new flashing goes on, the new whirlybird goes in, and the old one leaves with Dave.

Replacement in Perth is $350 for the first unit and $300 for each additional unit done in the same visit — the same price as a new installation, with disposal included.

Replace, or upgrade?

If the old setup kept the roof comfortable, replace like for like. If you were never happy with it — the upstairs still cooked, or your roof sits in a wind shadow — a replacement is the natural moment to move to a solar vent, which runs on still days and moves several times the air. That starts at $750 installed.