Checking the attic during or just after a rainstorm will help determine whether moisture problems are generated by interior or exterior sources.Įxamine the existing insulation for type, condition (dry, wet, compact, etc.), average depth and coverage. Some frost buildup is to be expected, but if it is particularly heavy buildup (10 mm or more), look to make sure ventilation is present and not blocked with insulation.

A tell-tale sign of air leakage is the discolouration of insulation, so do not hesitate to look under existing insulation to locate air leaks.Ĭheck the attic during or just after a cold snap for condensation buildup, which will appear as frost in cold climates. Typical problem areas occur around bathroom and kitchen vents that penetrate the ceiling, around plumbing stacks and chimney chases and at wiring penetrations and pot lights. Moisture can also come from inside the house, carried into the attic as water vapour by air leakage. Pay particular attention to water marks on the underside of the sheathing or along rafters.įigure 5-2 Some attics are easier to work in than others Typical problem areas include poor flashing at a hip, valley or the chimney and ice dam leaks. Moisture can come from the outside due to failure of the roof or flashing. Identify the cause and correct it before adding insulation. Mould or rot are sure signs of advanced condensation problems. Uncorrected moisture problems will reduce the effectiveness of insulation and can lead to structural damage such as wood rot or split rafters. In addition to checking for structural problems, check the condition of the roof framing, sheathing, finish and the soffit and fascia for signs of moisture problems such as leaks, stains, mould, flaking or rot. Attics or roofs without a working space are covered later in this chapter, in Part 5.4, Cramped attics, cathedral ceilings and flat roofs. Vertical clearances of less than 1 m (39 in.) will not allow you to move freely. Exterior-mounted, gable-end entries represent one less opening that will have to be air sealed, which offers ready access to firefighters in the event of a fire.Ĭheck the roof space for obstructions and ease of movement. If not, or if there is no access, you may be able to cut a hole in the ceiling in an inconspicuous place such as a closet. A hatch should be large enough to allow you to bring in materials.

Most houses with accessible attics have an interior ceiling hatch, although exterior roof or wall-mounted entries are not uncommon. A thorough inspection of the following features will help you to develop your retrofit strategy. Regardless of the type of attic or ceiling your house has, there are a number of things to examine before beginning work.

Rafter vent