Roofs and ceilings:
Roofs and ceilings work in conjunction to one another when it comes to insulation:
- Install insulation under the roofing material to reduce radiant heat gain.
- Install insulation in the ceiling to reduce heat gain and loss. In most cases ceiling insulation is installed between the joists.
To reduce the risk of electrical short circuiting, electrically conductive insulation must not be laid across ceiling surfaces or ceiling joists, or under subfloors. Electrically conductive insulation must also be secured with non-conductive staples.
Veranda roofs should be insulated in hot climates (where outdoor living spaces are used extensively) to reduce radiant heat gain. Heat build-up under verandas not only affects the space below, but can affect conditions inside the house.
Bulkheads (wall sections between ceilings of different heights) must be insulated to the same level as the ceiling, as they are subjected to the same temperature extremes.
External walls should be insulated to reduce radiant, conducted and convected heat transfer. Wall insulation can be installed:
- within cavities;
- within stud frames;
- on the outside of stud frames; and
- on the inside or outside of solid walls.
Depending on the particular situation, some forms of insulation can double as a vapour or moisture barrier.
Floors require insulation in cool climates and often in other climates. Insulate the underside of suspended floors:
- in cool temperate and alpine climates;
- in temperate climates in some cases; and
- in high humid and hot dry climates where air-conditioning is used.
Insulate the edge of slabs-on-ground:
- in cool temperate and alpine climates; and
- in temperate climates where slab heating is used.
Insulate the underside of slabs-on-ground:
- in alpine climates; and
- where groundwater is present.