Roof painting is common in Adelaide and so are hot summers. With the cost of electricity constantly increasing energy efficiency is a hot topic. So why not combine these two problems into one solution? Most roof coating manufacturers make a heat reflective coating so painting your roof and making it more energy efficient is totally do-able. So how does this work? What are some good products? and what difference does colour choice make?
Heat reflective paints ensure the surface temperature is reduced. Cooler surface temperature means cooler rooms below/
Basically the less heat that is absorbed by the roof the less heat can be passed through the roof to the rooms below. This is pretty common technology now. Bluescope steel's Colorbond is perhaps one of the better known coated systems which reflect heat (Zincalume or Colorbond: Which should I use for my roof). Having said that nearly all roof paint manufacturers will offer a heat reflective coating. The coatings reflect the infrared heat rays causing the surface temperature to be cooler. That's a big deal. Obviously, there are a lot of other considerations to be taken into account such as the materials under the roof and their ability to transfer heat. All consideration taken, it just makes sense.
What's even better is that heat reflective roof membranes look better for longer.
Because the coatings reflect the infrared radiation, they tend to look newer for longer which only helps to add even more value to the home. Some of the roof paint manufacturers will even give a longer warranty for heat reflective paints.
So what are some of the better products on the market today?
While there are a bunch of paint manufacturers which produce roof coatings, I prefer to use products which are safe for the environment and household drinking water (if water catchment to tanks is being done). Clean up is also an important consideration and water based coatings are definitely my preference. Depending on the type of finish you are after, my go too products are the Dulux Actatex Cool Roof (with Infra cool technology) or the Nutech NXT Cool Zone. These products have a 10 year and 12 year product warranty respectively. Another good product is the Roofcote Supacool membrane but it only comes with a 7 year warranty. Aztec Energy Star is also a good product but has a more complex application system and clean up.
Colour plays an important part in keeping surface temperature down.
It is pretty widely known that the lighter the colour, the better the colour is at reflecting heat. The fact remains that a light coloured roof has a better Total Solar Reflectance (TSR) rating than a dark coloured roof with a heat reflective coating. For example a charcoal roof will have a TSR rating of less than 10% while a white roof will have a TSR rating of above 50%. Even after coating with a quality heat reflective coating, the charcoal roof will still have a TSR rating at around 35% while a white roof with heat reflective coating will be around the 90% TSR rating.
Unfortunately council regulations sometimes prohibit the colour due to high solar reflectivity.
In Adelaide this can be the case if your roof is on a hill or is highly visible and may cause driver or pilot distress.
Heat reflective coatings cost more, so are they worth the money.
Well that depends on the individual. In my opinion, if you need to have a dark coloured roof because of the aesthetic appeal, then yes, I would definitely recommend a heat reflective coating. If you are choosing a lighter colour, it's still a good idea. Not only are they more energy efficient, they will also stay looking better for longer. If you want an idea of how much a roof restoration will cost in South Australia, read my post- How much does a roof restoration cost?
If you are after an honest opinion for your situation, are wondering what product to use or live in South Australia and are after an quote - I am happy to help