Fire and other hazards in attics
Figure 5-4 Keep combustibles away from an insulated metal chimney
Metal chimneys
Factory-built metal chimneys should be kept from contacting insulation by a minimum 75 mm (3 in.) unless otherwise specified by manufacturer or local authorities. Install a non-flammable radiation shield that maintains a 75-mm (3-in.) air space between the chimney and insulation. To reduce air leakage, first air seal the fire stop to the air and vapour barrier with non-combustible sealant. The top of the radiation shield should also be a minimum of 75 mm (3 in.) higher than the level of existing or new insulation to be added. To prevent insulation from falling behind the shield, attach a clamp-type storm collar without sealant at the top of the radiation shield.
Figure 5-5 Keep insulation away from a recessed light fixture by creating a barrier
Electrical installations
Work safely around electrical wiring (turn off the power). Consult with an electrical contractor if questionable wiring or corroded electrical connections are present.
Recessed lighting
Standard interior recessed lights are difficult to air seal effectively and can become a fire hazard if covered with insulation. Replace with approved airtight recessed fixtures or covers that can be installed safely under insulation.
Animal droppings
If you find a significant amount of animal droppings and vermin in the attic, do not disturb them because they can harbour easily airborne moulds, parasite eggs and bacteria that can cause severe illness. See Health and safety considerations, for more information.
Figure 5-6 Sealing the plumbing stack
