Roof & Attic Insulation

Up to 30% of heat loss in a house occurs through the attic. While installing good quality insulation may cost you, you will make a return on the investment within two or three years due to reduction in heat loss, which correspondingly reduces your energy bills. 

There are different types of insulation that you can use in your roofing. Each type of insulation has a different insulation value or U-Value - the lower the U-Value, the better the insulating material. Typical insulation in an attic should be more than 20-30cm thick unless you are using more advanced thinner materials. Here are a few of the most common types of insulation that you can purchase at your local DIY store:

• Sheep’s wool – This type of insulation is made from sheep’s wool. Sheep’s wool is a very good insulator, but can be a more expensive than other insulating materials.

• Fibreglass – Fibreglass is made from molten glass spun into microfibers. It is probably the most commonly used form of roof insulation and can be purchased from most DIY stores.

• Rock Wool – Rock wool is made with molten rock instead of glass.

• Cellulose - This is made from shredded recycled paper. It is not as common but it is a great insulator.

• Eco insulation - This can be made of a range of recycled materials, such as plastic bottles or paper.

• Reflective foil thin insulation – This type of insulation is thinner than regular insulation, it has many layers of foil with fibrous material in between.

• Foam and cavity wall insulation.
   

Ask at your local DIY store to see what depth of this material you should install, as the type and insulation values differ product by product.
  
It is important to remember that each of these insulation materials will have a different primary energy footprint, that is, the energy that is used in production. Rock wool production for example is energy intensive, while sheep’s wool is less energy intensive. Other factors such as the distance the material travels from the supplier should also be taken into account to ensure the minimum amount of energy is expended. Each house is different and the final decision is up to the resident.

More information on household insulation can be found in the SEAI Detailed Guide to insulating your Home PDF.