# Whirlybirds & Roof Ventilation — Crown Roofers Sydney

> Roof ventilation sized and positioned properly — one vent per 50 m² of roof, high, with matching intake at the eaves.

**URL:** https://www.crownroofers.com.au/services/whirlybirds-roof-ventilation  ·  **Phone:** [0490 688 332](tel:+61490688332)

An unventilated Sydney roof cavity gets extraordinarily hot. In the west it will sit at 60-70°C through a February afternoon, which cooks the ceiling insulation, pushes heat down into the rooms below and drives your cooling costs up. In winter the same cavity traps moisture, and that is where ceiling mould starts.

Ventilation fixes both, but only if it is sized and placed correctly. The rule we work to is one whirlybird or ridge vent per 50 m² of roof area, positioned high on the ridge with matching intake at the eaves — air has to come in somewhere for anything to leave. Undersized or badly positioned units are the most common thing we find already installed.

If your existing setup is adequate, we will tell you that rather than sell you more of them.

All work is carried out under NSW Building Licence 471250C, covered by $20M public liability and backed by our 10-year workmanship guarantee.

## Why Crown Roofers for this service
- **Sized to the roof** — One vent per 50 m², not a number picked at random.
- **Intake as well as exhaust** — Vents without eave intake achieve very little.
- **Honest assessment** — If what you have is working, we say so.

## Signs you need this service
- A roof cavity that is stifling in summer
- Upstairs rooms that stay hot long after sunset
- Condensation or mould appearing on ceilings
- Existing whirlybirds that never seem to turn

## FAQs
### How many whirlybirds do I need?

Roughly one per 50 m² of roof area. Two units on a large roof with no eave intake will underperform badly, which is a very common setup.

### Do whirlybirds actually work?

Correctly sized and placed with adequate intake, yes, measurably. Undersized or without intake, they largely spin without moving much air.

### Will it leak?

Not when flashed properly — the flashing is the part that matters, as with any roof penetration.

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## About Crown Roofers

- **Phone:** 0490 688 332
- **Website:** https://www.crownroofers.com.au
- **NSW Building Licence:** 471250C
- **Public Liability:** $20 million
- **Workmanship guarantee:** 10 years on every job
- **Service area:** Greater Sydney metropolitan area + Wollongong
- **Hours:** Mon–Fri 7am–6pm · Sat 8am–2pm · 24/7 emergency line
- **Ownership:** Sydney-based, family-owned and operated