Insulation keeps your home both warm and cool.
Unless you have a flat roof, or a cathedral ceiling, the space between your ceiling and the roof acts like a buffer against the sun beating down and also the loss of warm air from heaters in winter. Placing insulation somewhere in the ceiling cavity helps to improve the buffering, making your home cooler in summer and warmer in winter.
Another reason you might insulate is to keep out noise. If your home lies in a flight path, then putting insulation in the ceiling would dull the sound of aeroplanes, and it will also reduce the sound that a metal roof makes as the sheets contract and expand.
When SR lays your insulation, it is done on top of the battens or purlins because this is more effective at stopping heat from entering or leaving the ceiling cavity. However, it is possible to put insulation directly on the ceiling, which can be done by almost any handyman and saves you taking the roof off. Be aware though, if it isn't done correctly, it can be a fire hazard if it gets too close to down lights or other electrical fittings, and it seems less effective than putting it up against the roof sheeting.
The main types of insulation are:
- Fibreglass, which is treated with a fire retardant is a good insulator and relatively inexpensive to lay. Fibreglass batts are placed on the ceiling and fibreglass blankets are placed under the roof. When working with fibreglass it is recommended that you wear a mask and gloves as the fibres and dust can cause irritation.
- Sheep's wool, which is natural, non-toxic and slow to burn is as effective as fibreglass. Special wax-tipped screws are required to screw down the roof sheeting because ordinary roofing screws get tangled in the fibres and don't hold the sheets down properly. This makes it more expensive to lay than fibreglass or aluminium foil.
- Aluminium foil is light and cheap to install, but it is less effective against the loss or entry of heat, and also less effective as a noise barrier.
- Aluminium bubble foil is very effective, but it is expensive in comparison to fibreglass insulating blankets.
Insulated sheets – as well as insulation that is purchased separately from your roofing iron, some sheeting comes with its own insulation. See the Specialised Roofing section for more details.