Insulation blocks heat flow in to and out of your home. This means that your home can be kept warm during the colder months and it can be kept cool in the hotter months. Effective insulation means that less heating and air conditioning is needed, which reduces energy bills. This also lowers the number of greenhouse gases produced.
Where to fit the insulation
Insulation can be used under the roof, on external walls, under floors and slabs and in the ceiling. Insulation installed under the roof lowers heat gain from the sun's radiation. Insulation fitted in the ceiling decreases heat gain and loss from your home. Ceiling insulation is typically installed between joists. Insulation can also be installed within external wall cavities, within or outside of stud frames and on the outside or inside of external walls. External wall insulation lowers heat gain from the exterior. Some forms of insulation may also provide protection from moisture.
Types of insulation
There are two types of insulation: bulk and reflective. All insulation should meet the required standards, even if the insulation is imported. Insulation is rated according to its effectiveness, as well as the direction of heat that the insulation resists. The higher the rating, the more insulating the material is. The directional rating that is suitable for your home will differ depending on where you live. In general, materials that resist downward flow block heat from the sun and materials that resist upward flow resist heat loss from the interior of your property.
Bulk insulation uses pockets of trapped air to block heat. This is an effective type of insulation because it can typically resist heat gain and loss in both directions. Materials that offer bulk insulation include polyester, polystyrene, cellulose fibre, glass wool and wool.
Reflective insulation primarily reduces heat gain from the sun's radiation. It does this by reflecting the heat. Reflective insulation uses a layer of air adjacent to a reflective surface. It typically includes aluminium foil on paper or plastic. An issue with reflective insulation is that when dust forms on the reflective surface, the effectiveness of the insulation is reduced.
Reflective surfaces should be faced downwards or placed vertically. If reflective sheets are being used, the anti-glare surface should be facing upwards or outwards.
There are some composite materials available which combine features of both bulk and reflective insulation. This includes foil faced boards and blankets.