FAQs

The density of glasswool products used in residential applications varies depending on the use of the product. Ceiling batts are normally in the range of 8 – 10kg/m³ whereas wall batts need to be stiff so as not to slump in the wall cavity and these products are typically 12kg/m³ or more. Acoustic insulation products are typically in the range of 25 – 30kg/m³.

Glasswool and rockwool are similar products that perform similar functions. Glasswool takes molten glass (made from around 80% recycled glass) and put this through a fiberising process to create a mat of varying thicknesses and densities. This mat has millions of air pockets created and this provides an effective insulation against the transfer of heat. Rockwool is made in a similar way from molten volcanic rock (basalt) rather than glass. The main differences between glasswool and rockwool from a performance perspective is that rockwool cannot be made a low densities like glasswool can. The minimum density for rockwool is around 30kg/m³. However, rockwool has the advantage of being able to be used at much higher operating temperatures – up to 850°C compared to 350°C for glasswool. Mineral wool is a term that describes both glasswool and rockwool.

This depends on the system used and direction that the heat travels. Reflective insulation products are effective at resisting radiant heat but less effective with convective heat. Therefore, they work better in summer (heat down) situations than winter (heat up). As a basic “rule of thumb” roof sarking in a ventilated pitched tiled roof with a flat ceiling can provided added R-value of around R1.8 in summer and reflective wall wraps (when combined with a non-ventilated still air space in the stud void) can add around R1.1 in summer.

It is very difficult (and sometimes impossible) to insulate cathedral ceilings after they have been built. 

If the cathedral ceiling has exposed rafters then it’s virtually impossible to insulate without a major structural change to the roof. If the rafters are not exposed (i.e. they sit behind the ceiling lining), then a cathedral ceiling can be insulated with Bradford batts by removing either the roofing material or the ceiling lining but obviously this is a difficult and expensive process and would only be cost effective if a re-roof was being done for other reasons or if other alterations were taking place that required the ceiling lining to be replaced.

Insulation in Australia must be tested as per the standard AS/NZS4859.1. There are different tests for different types of insulation. For the most popular insulation which is glasswool, which we market as Bradford Gold Batts, we test in an apparatus that the claimed thermal performance (R-value) of the product is the same as what we claim on the packaging. This is done in the factory as part of our quality control process.

Having established that the thermal performance is accurate, we then use this in modelling to estimate how much energy a home will need to achieve a comfort level of between 22 – 26 degrees Celsius. Because a well insulated house requires less energy to achieve this comfort range this helps improve the energy efficiency of the home.

The great benefit of creating an insulation product out of glass fibers is that they are inert and strong to provide lifetime performance. However when the fibers are cut to shape at the factory, some sharper edges and a small amount of loose dust is generated.These may cause minor temporary irritation for some people during installation. This is a mechanical irritation not chemical – it can be relieved by washing with soap and water or avoided by installing with dust mask and long sleeve shirt as recommended by Bradford.

After installation there is no risk of irritation if left undisturbed. In general roof spaces and building sites are dusty environments and Bradford recommends protective equipment be worn when working with any material in these spaces.

Bradford Anticon is an insulation that is installed at the roof line whereas batts are typically installed on a horizontal ceilings. Except in the case of cathedral ceilings, Anticon is effective at keeping heat out of an attic space and stopping heat from escaping from the roof. 

However, batts work at the ceiling level which is closer to the living areas of the home. Anticon is an excellent “added” insulation which has other benefits when metal roofing is installed – in particular acoustic insulation against heavy rain or hail and management of condensation which can occur in colder parts of Australia. Bradford recommends that Anticon be used in combination with batts but not as the primary insulation except where winter heating is not used.

Bradford’s ceiling insulation will not increase the fire load in your roof space and is non-combustible. Care should still be taken around down lights to ensure enough space has been left to allow transformers and lights have enough natural ventilation to cool (required by Australian Standards).

Yes, it can. Although, there are some loose fill products that will exceed the weight recommendations by plasterboard manufacturers. All of Bradford’s glasswool products are safe to install on plasterboard ceilings.

Operating temperature For low temperatures down to -40oC Polystyrene pipe insulation is recommended when combined with a suitable vapour barrier. For operating temperatures up to 450oC, either Glasswool or Rockwool SPI (Sectional Pipe Insulation) is recommended. Rockwool is recommended in the upper temperature range because of its greater thermal resistance and compression resistance under operating conditions. For high temperatures up to 650oC Rockwool Pipe Insulation is used. 

Cost control For "large" pipes (200mm diameter or greater) Fibermeshª 650 may be cost effectively substituted for Rockwool Pipe Insulation, particularly on large projects and where damage via mechanical compression (e.g. personnel climbing over pipework) is a minimal risk. Generally an extra 13mm insulation thickness is required for performance comparable with pipe insulation.

THERMAL

Insulation's ability to resist heat flow (prevent heat leaking in or out) is described as its 'R-value'. Incorrect installation, such as compressing or damaging insulation, or leaving gaps between sheets or batts, can result in a product not achieving its specified R-value. This is why it’s important to choose a supplier that you can trust, like Bradford, who has had years of experience and has a reputation of providing quality service.

Bradford has a range of products with various R-Values. Factors like the local climate and available budget should be considered when determining what product best suits your needs. In warmer climates, care should be taken to ensure summer heat does not enter the home and get “trapped” by insulation. Effective shading of windows is highly recommended. Bradford’s Hi Performance range provides the highest available R-Value product in Australia – the R7.0.

It’s important that you understand what R-values mean because they can result in you getting the best product for your home. Understanding the R-value for your home is regarded as the best way to compare the different products that are out there in the market.

R-values are the measuring tool we use to rate the level of thermal resistance. Essentially, the higher the R-Value the more effective the insulation is.

Bradford has a range of products with various R-Values. Factors like the severity of the weather conditions and available budget should be considered when determining what product best suits your needs.

Material R-values are supplied with bulk insulation (such as Bradford Gold insulation batts) and refer to the insulating value of the product itself.

Total R-values are supplied with reflective insulation (such as Bradford Thermoseal roof sarking products) and depend on the product being installed as specified. R-values can differ depending on the direction of heat flow through the product, more so in reflective insulation rather than bulk.

• ‘Up’ R-values describe resistance to heat flow upwards (sometimes known as ‘winter’ R-values).
• ‘Down’ R-values describe resistance to heat flow downwards (sometimes known as ‘summer’ R-values).

All new homes being built in Australia have certain energy efficiency levels they must meet as required by their state. By taking into account the R-values of the product this will help you comply with what your state requires.

THERMAL

There are three main types of heat transfer:

1. Radiation

These are rays of heat moving through the air in the same way as we feel the heat from the rays of the sun on our faces. It’s the way your grill works, transferring heat to the food without touching it.

2. Convection

Convection occurs when air molecules themselves heat up and move to another location. In the same way as a convection oven directly heats the air and then blows it around the food, so air can transfer heat in and out of your home. 

3. Conduction

Heat is transmitted through the materials of your home, such as the roof and walls. For example, when you place a pot on a stove the inner surface heats the food, because the heat is conducted through the base of the pot.

THERMAL

Bradford Gold insulation is made up of very thin glass fibres that are matted together to form millions or air pockets. These air pockets are very poor conductors of heat and resist the flow of air or radiation through the insulation. 

This ‘resistance’ is known as the R-Value. The higher the R-Value the more effective the insulation is. 

ACOUSTIC

Nothing beats peace and quiet. That's why it is important to consider good acoustic insualtion when building a home. Noise has the ability to raise stress, disrupt sleep and generally reduce your quality of life.

These days, there is more external noise – as traffic and housing density increase. Even within our homes, trends such as open plan living, harder surfaces (e.g. timber floors), and more powerful entertainment systems increase noise levels.

Installing acoustic insulation in external walls when you're building your home is the easiest way to effectively reduce unwanted outside noise from heavy traffic, aircraft or noisy neighbours. Also, installing acoustic insulation in interior walls or between first floor ceiling and second storey floor can reduce sound power by up to 75%.

ACOUSTIC

Sound travels easily through the air. When sound waves reach a solid surface they are partially absorbed, but they also cause vibrations that can transmit sound to the other side.

In this way, external noise is easily transmitted through walls and ceilings to the inside of your home. Additionally, noise generated from within your home can be transmitted through internal walls, and even floors, to adjacent rooms.

How insulation helps

Bulk insulation materials such as glasswool and rockwool act like a sponge to help soak up sound energy. When the sound waves encounter the insulation they are partially deflected by the density of the product and partially absorbed due to the millions of interconnecting air pockets.

Insulation products such as reflective foil or foams with hard surfaces are poor noise insulators.

Bradford SoundScreen has a similar structure to Bradford Gold insulation, but is much denser. This extra density makes SoundScreen particularly efficient at stopping noise, as well as heat transfer within your home.

ACOUSTIC

Sound pressure is measured in decibels (dB), which is a logarithmic scale. A 10dB increase in sound level is heard as roughly double the loudness of the original sound by the ear. Sound levels between 35dB – 45dB are generally considered comfortable.

The acoustic performance of a wall or floor system is measured by the Weighted Sound Reduction Index (Rw). It is a single number acoustic rating that takes into account the sound reduction of the system at a number of different frequencies and is used to easily compare different types of construction. The higher the Rw the better the acoustic performance of the system.