Before you rush out and buy bags of insulation for your ceiling, head up into the ceiling cavity and measure the distance between your ceiling joists. These are the structural members that the ceiling is fixed to. Insulation batts come in different widths to suit common joist spacings. Also do a rough measure of the ceiling space to work out how many packs you will need. Each pack states how large an area it will cover and takes into account the thickness of the ceiling joists when calculating this.
Choose your R value
The R value of bulk insulation is a measure of how effective it is in resiting heat transfer. The higher the number the more insulating power the product has. It’s best to go for the highest number possible so your home is better insulated.
There’s a wide range of materials available to use in your ceiling. Glasswool batts are the most well known but there’s also polyester and natural wool. While generally the cheapest option, glasswool batts are harder to work with as they can irritate the skin. Polyester and wool are easier to work with but cost a bit more. When comparing products, make sure you look at those with the same R value.
When you’re putting in the insulation, make sure there are no gaps around it where the heat can escape. It’s also important you get right into the corners of the ceiling space, even if it is a tight fit. Do not compress the insulation, as this will reduce its effectiveness. Where you need to cut it, use a sharp knife. It’s also important that you don’t cover any downlights or the transformers that power them. These fittings generate heat and covering them can create a fire risk.
When working in the roof space, it’s important to have the right equipment and to work safely. Wear a dust mask and gloves while long-sleeved shirts and pants are important if you’re using some types of glasswool as they can irritate the skin. Always walk on the ceiling joists and not the ceiling as you will go straight through it. Also, take care of exposed electrical wiring and light fittings.