Ceiling Insulation


Installing or adding ceiling insulation to an existing one can make a significant difference to the comfort and energy performance of the home, but it is vital that the insulation is put in correctly. Ceiling fires have increased significantly with the more common use of downlights that penetrate the ceiling. Take care to maintain minimum clearances around downlights and ensure that transformers are not underneath the insulation. Wherever possible avoid using recessed light fittings as they also shed a great deal of heat through the gaps required in the surrounding ceiling insulation. Recessed lights and their auxiliary equipment should be installed in a manner designed to prevent the light and equipment overheating and igniting surrounding combustible materials. Particular notice should be taken of manufacturers’ installation instructions for lights that include warnings about covering them with insulation or display the following symbol meaning ‘Do Not Cover’. Installing ceiling insulation in blanket format is the more modern method. It creates a very complete thermal envelope in the ceiling as the insulation is rolled out over the top of the ceiling joists essentially ‘blanketing’ the whole ceiling.

The insulation comes in roll form rather than pre-cut segment. With the blanket system it is very important that the cavity under the blanket is filled in before the blanket is laid. If you are starting with no insulation, experts recommend installing a lighter layer between your joists first and then laying another blanket layer completely over the top. The cavity left by just installing a blanket over the top of the joists can easily be compromised resulting in significant heat loss. Whilst more insulation material is used to insulate the ceiling, the grade of material can be dropped to achieve the same level of performance as segment insulation. The major disadvantage of blanket insulation is that it can become hazardous to walk across the ceiling as the joists are no longer visible. Secondly because the insulation sits on top of the joists, and not hard against the ceiling there is a pocket of air trapped between the insulation and the ceiling. If this pocket is compromised, for example when one portion is moved, then thermal performance drops. What this means in real terms is that it becomes more important that insulation is fixed up by tradesmen or others working in the ceiling space when they have finished.

Advantages of installing a ceiling insulation:
  • It is an economical option.
  • Achieves a higher thermal performance level by thickness than other materials meaning it can often be fitted into tighter spots than other products.
  • Is easy to work with when installing as it can easily be cut and manipulated around fixtures in the ceiling such as downlights and fans.
  • Bales can be tightly wrapped and compressed making them easier to move into the attic space.
Most common types of ceiling insulation that are installed nowadays are polyester and fiberglass. Full polyester insulation is becoming more and more popular as an alternative choice to fiberglass. It is manufactured to the same performance levels as other types of insulation but has a number of distinct advantages. Fiberglass is very much the traditional mainstay of insulation. It is a very common product both here and around the world used in both new and older homes. The product is manufactured from glass and usually contains around 30% recycled glass.

Comments