In the hot Australian conditions of summer, metal roofs can get extraordinarily hot. Your roof space needs proper roof ventilation to ensure sufficient airflow to regulate the temperature in your home. This ventilation will prolong the life of your metal roof.
Adequate ventilation will also prevent moisture from spreading in the roof cavity, which could cause structural damage to your home.
Let’s explore the purpose of roof vents further and compare the best options for metal roofs in particular.
Why is roof ventilation important?
The two primary varieties of roof vents are those mounted at the roof’s ridge and those installed at the eave. The eaves vents are ‘intake vents’, usually letting air flow in, while the ridge vents are ‘exhaust vents’, allowing air to escape from the roof space.
Ridge vents can be more challenging and expensive to install, but they are more effective in venting heat and moisture. Eave vents offer a cheaper installation process but are less effective in venting heat and moisture.
There are three key reasons to install roof vents in your metal roof:
- Moisture reduction
- Extending the lifespan of insulation
One of the most effective ways to increase a roof’s energy efficiency is to vent it. Venting keeps the inside of the house warmer in the winter. It also makes it cooler in the summer by giving heat and moisture a way to escape.
Roof vents keep the area dry by allowing air to pass through the roof cavity. This dryness means there is a chance of mould and mildew developing from humidity to cause long-term damage. The dryness and the stabilised temperature also extend the insulation’s lifespan. By preventing heat from accumulating in the first place, venting your roof can increase the lifespan of your insulation by up to 50%.
These three reasons hold true for any roof but are especially relevant for metal roofs that can really absorb heat during the Australian summer.
Passive vs. active ventilation
The best roof ventilation systems often combine a mixture of active and passive ventilation.
Passive ventilation uses natural airflow and directs this through into your attic space to remove moisture and heat. Active ventilation incorporates fans to force the airflow.
Why do people choose metal corrugated roofs in Australia?
Metal corrugated roofs offer many benefits for Australians compared with other roofing options.
- It’s durable – resistant to weather extremes, fire resistant, anti-corrosive, and pest resistant. Its strength-to-weight ratio makes it an excellent choice.
- It’s cost-effective – corrugated metal roofs are much cheaper than many other roofing options, including slate or terracotta tiles.
- It’s flexible – a metal roof is versatile and can fit with many different home designs. You can now choose your colorbond colour to fit with the design of your home, too.
- It’s eco-friendly – Metal roofing is 100% recyclable.
Roofing is one of the most crucial aspects of any structure. Choosing the proper roofing material influences how much maintenance is required over the life of the building. It determines how well the structure is protected from the elements and will ultimately affect the property’s overall value.
If you’ve chosen corrugated metal for your roof, the next step is to evaluate your ventilation needs.
What are the roof vent options for metal roofs?
We’ve already established the necessity of proper ventilation for your metal roof. Let’s run through some of your options.
1. Ridge ventilation
Ridge ventilation is one of the most efficient methods of venting a roof. It allows hot air to escape through the roof’s ridge while drawing cooler air in through the soffits or eave vents. This keeps the attic space cool and dry, preventing moisture and condensation from accumulating. Ridge vents are available in various sizes and styles to fit any home and can be used on shingled and metal roofs.
RapidRidge is also an example of a low-profile design vent because these ridge vents minimally affect the roof’s aesthetics. They are much more visually pleasing than other bulky, obtrusive vents.
Whirlybirds, also known as wind turbines or roof ventilators, are devices used to exhaust hot air and moisture from the attic space of a building. They are an example of active ventilation. They typically consist of a rotating cowl mounted on a mast, which draws hot air out of the attic as it spins. Metal roofs are ideal for whirlybirds as they provide a good surface for mounting the devices.
The effectiveness of a whirlybird ventilation system will vary depending on several factors, including attic size, the location and orientation of your roof, and the local climate wherever you live. For example, on a basic level, whirlybirds need wind to work. No wind = no ventilation.
3. Solar-powered ventilation
Solar-powered ventilation involves panels on your roof that convert sunlight into electricity, which is used to power fans or other equipment that provide fresh air and regulate the temperature in a building.
Of course, solar panels are a greener choice, using renewable energy. As such, solar-powered ventilation is both eco-friendly and a great investment for any homeowner looking to improve their home’s energy efficiency.
4. Gable vents
Gable vents allow hot air from the attic to escape while also allowing fresh air to enter. Gable vents are one of the most common methods of venting a metal roof, though obviously only fit with the gable style. You can install a gable vent near the peak of the roof’s gable end. Gable vents are available in various styles and sizes to suit the needs of any home.
Remember local laws
In Australia, the installation of roof ventilation systems for metal roofs is regulated by building codes and standards. These are incredibly stringent in places that are prone to bushfires. Measures vary from state to state, so you should research or consult a professional before committing to a ventilation option.
You’ll also need to consider things like an ember mesh for your roof to guard against fires.
Choosing roof ventilation
There are many factors to consider when choosing the right roof ventilation system for your home. You’ll need to consider budget, roof size, climate, and many other factors, on top of the fact you’ve chosen a corrugated metal roof.
Check out our blog on the specific benefits of roof ridge ventilation for more information.