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Bastion 300mm Aluminium Roof Vent

For Installation Prices in Sydney Area – Click Here

The Bastion 300mm is another Bunnings Whirlybird vent. Like Brutus, Bastion is not a very widely known brand name, although the vent does feature a quality construction.

The 300mm throat size makes this vent equally suitable for domestic and modest industrial uses. Although it doesn’t offer a heavy-duty performance, it is effective in ventilating roof space from 90m2 to 120m2. Bastion 300mm operates year-round and runs entirely on wind energy.

In summers, it reduces the load on your air-conditioning system by ventilating indoors and keeping temperatures low. In winters, it removes moisture-laden air from the ceiling space to prevent snow reforming and mitigates the need for heating the interiors. As a result, Bastion 300mm is very effective in helping bring down your energy costs year-round.

The ventilator has a sturdy aluminium make. This means that it can effectively withstand high wind speeds, rain and other weather conditions. It is also rain-proof, so you don’t have to worry about rain seeping through the vent space.

Bastion 300mm has a mill finish which gives it a classic look. The immaculate finish makes it equally suitable for more modern roofs. The ventilator is quite light-weight, so you can easily lift it and install it on a rooftop.

Although it promises to deliver a solid performance, Bastion 300mm does not come with a warranty. This is offset by the incredibly affordable price tag which this model bears. For those willing to take some risk, this ventilator is a very promising choice.


  • Wind-driven turbo ventilator
  • Suitable for medium to large roof spaces
  • Available in mill finish
  • Durable aluminium construction
  • Effective for ventilating hot air and moisture
  • Weather-proof design to prevent rain seepage
  • Very affordable price tag


about us

We have been in business for over 30 years as a commercial & residential roofing company. RVA is the sister company of Sydneyroof.  At RVA we are focused on Industrial & Domestic roof ventilation, fibreglass skylight panels, and roofing utilities. We believe these areas of the roofing industry have been largely marginalised.  We however, are focused on taking this part of the industry and creating a service-oriented response to our customer's needs.

Why Us?

Competitive Prices

Our pricing is transparent and highly competitive. We do our best to take the guesswork out of the final cost at the beginning.


We take pride in our workmanship and are proud to warranty our workmanship for 5 years, in addition to the manufacturer's warranty.

Over 30 Years Experience

Nothing says commitment like longevity! We are proud of our commitment to our craft and our customers.