Concrete and Terracotta Roof Tiles
– A smarter choice for sustainable roofing

Low embodied energy

• Concrete tiles are produced using a low intensity production process when compared to other roofing materials.
• Terracotta tiles are produced using abundant natural materials which emit negligible pollutants relative to other roofing materials.
• Both Terracotta and Concrete tiles are easily replaced, can be recycled, are reusable and offer ‘long life’ performance when considered as part of an overall LCA (life cycle assessment). Other ‘thinner’ roofing materials have higher embodied energy and a lower product life cycle.

Thermal insulation, reducing energy usage and spend

• Tiles have a thermal advantage over other higher conductive roofing materials such as metal. Additionally tiles with a low ‘solar abosorptance’ rating can offer roof air-space temperature reductions of up to 9 degrees.
• For the ultimate roofing system that will contribute significantly to reduced carbon emissions and energy usage, a combination of Concrete / Terracotta roof tiles, Enviroseal underla and Gold Batts.

Tank water safe

• Tests run by NATA approved laboratories confirm the suitability of harvesting water runoff from tiled roofs as complying with World Heath Organisation standards for drinking water. However, other factors including atmospheric fallout needs to be considered and the inclusion of a 'first flush' diverter system is recommended.

Acoustic performance

• In locations where significant noise pollution is apparent, eg: aircraft noise or in areas of high density living, tests have confirmed that a tiled roof has a sound reduction potential of 30 decibels, double that of other thinner roofing materials.

When it comes to energy efficiency and the environment,
Monier bricks offer a lifetime of benefits.

The brick industry has done a significant amount of research into brick in regards to energy efficiency and the environment. In 2002, Think Brick Australia embarked on an 8 year thermal research program, in collaboration with the University of Newcastle’s Faculty of Engineering and Built Environment, to understand the role of clay masonry (bricks and roof tiles) in achieving sustainable design. To date, the research has proven clay brick to be a superior building material in producing thermally comfortable, energy efficient environments for people to live, work and play. For more information on this study visit www.thinkbrick.com.au.

Bricks are an essential part of energy efficient design
Bricks build in thermal mass. This mass is a key part of passive design, a proven method of keeping your home at a comfortable temperature all year round and reducing the need for heating and cooling devices. Thus, lowering electricity loads and your costs.

"Thermal mass acts as a "thermal battery". During summer thermal mass absorbs heat, keeping the house comfortable. In winter, the same thermal mass can store the heat from the sun or heaters to release it at night, helping the home stay warm."

Bricks are energy efficient in manufacture
Using the measurement known as Embodied Energy (the energy consumed in the manufacture of various building materials) the CSIRO has concluded that clay bricks have less Embodied Energy than aluminium, steel, glass, or timber.

More importantly, over the lifetime of a home the energy consumed in the manufacture of the materials accounts for only 5%. The other 95% is the ongoing running of the home, of which a significant proportion is for heating and cooling. The less of this required, the less direct impact there is on the environment.

Bricks are energy efficient in application
Brickwork can be very energy efficient, but designing a house to be cool in summer and warm in winter must take into account more than just the walling material. There are four key factors:

• Orientation – Placement of the house in relation to the sun.
• Insulation – A wall’s ability to isolate temperature.
• Ventilation – Air flow through the house.
• Mass – Heavy weight wall materials slow the passage of heat through a wall, a process called ‘thermal lag’. And the easiest way to get this heavy mass into walls is brickwork. The heavier the brick, the higher its thermal value.

The R-Value – is it the right measure?
Another issue highlighted by research is a deficiency in using the Thermal Resistance Value, or R-value of the wall, to measure the thermal efficiency of a building.

During a hot spell in February 2004, the data from the brick veneer and cavity brick buildings indicated the "greater mass of cavity brickwork construction reduces the internal day-night temperature swing when compared to the insulated brick veneer despite the latter form of construction having a higher Thermal Resistance Value".

The thermal mass of clay bricks provides a time delay for heat transfer through the walls known as thermal lag.

It can be seen that high density walling materials do not fair well when assessed purely on the criteria of "R-value", however, when assessed on Thermal Capacitance clay bricks outperform their lightweight counterparts. It is for this reason that clay bricks are thermally more effective than the "R" value alone would indicate.

Think Brick has a myriad of information regarding clay masonry, including specific Climate Design initiatives and a Reference Library, and can be found at www.thinkbrick.com.au.

Principles of passive solar design