The access into the attic is usually somewhere on the top floor. The attic is an important part of the house. In the attic, your home inspector will check the condition of the roof structure, insulation, ventilation, and electrical wiring. Other things to check are signs of roof leakage and evidence of condensation. Another very important part of the attic inspection is the chimney.

Access into attics is sometimes not possible due to the absence of any access opening. Other factors preventing a proper attic inspection include storage of personal property items and low clearance. Sometimes, the attic access opening is visible but not accessible.

Rooms with cathedral ceilings occupy what would otherwise be attic space. Usually, it is not possible for your home inspector to see the roof structure over cathedral ceilings.

In some old house attics, and especially in attics of old barns, I have seen light coming through small holes in worn out roof shingles. If your home inspector finds this in an attic, it is pretty likely that the roof shingles will need to be replaced new.

Another roof item to check while in the attic is whether or not there is felt underlayment under asphalt strip shingles. If the roof is sheathed in plywood, your home inspector probably will not be able to see into the seams between the plywood sheets. However, there are usually 1/4 inch gaps between roof sheathing boards. Your home inspector will probably peer into several of these gaps to see if felt is visible. Felt underlayment generally has a dull, nonreflective surface while the back of asphalt strip shingles is dull but has tiny reflective specks. In addition, you will be able to see the butt joints between shingles if there is no felt. Later on, your home inspector will be inspecting the roof from outside.

Condensation is often found in attics regardless of the age of the house. Condensation is most likely to occur during cold weather while warm, moist air is escaping into the attic from interior heated space. The temperature of the roof structure during cold weather is usually below the dew point. As the air moves over the relatively cold roof structure, water vapor condenses on it. The condensation is either water or, if the temperature of the roof structure is below freezing, frost. In some attics, I have observed condensation frost melting and refreezing or melting and dripping onto the ceiling insulation. Ceiling damage caused by dripping condensation is often mistaken for roof leakage. If your home inspector is in an attic during warm weather, he will not have the opportunity to observe the actual condensation. However, he might find evidence of past condensation such as black mildew staining, dripline impressions in insulation under roof rafters, and even fungus on roof structure components. The root cause of heavy condensation should be found and corrected since the build-up of moisture can rot the wood roof structure.

In the attic, your home inspector will often find bathroom ceiling vent fan exhausts contributing to condensation. What I sometimes do is turn on the bathroom ceiling vent fans before I enter the attic. This helps to locate the exhausts. They should vent directly to the outside.

Look for evidence of small animal entry. For example, if there are bats in the attic, you can hear them emit sharp clicking sounds and you can also smell the guano. Sometimes there are accumulations of guano on the attic floor.

It is not unusual to find that a house pet such as a cat has been napping in the attic and left impressions in the insulation. Racoons and squirrels commonly do this also. Keep a sharp eye for daylight openings through which a squirrel or bat could enter the attic. Sometimes the screens are missing or damaged behind gable end vents, soffit vents, or roof surface vents. On older houses, there are sometimes openings rotted through gutter and fascia trim on the eaves. Sometimes, these openings are not visible from the attic and you're home inspector will have an opportunity to find these openings later on during the inspection of the exterior and roof.

In attics, I frequently lift up insulation bats if I suspect there might be squirrel or mouse nests underneath. In one seasonal cottage, under attic insulation, I found a carpenter ant infestation. Carpenter ants are often attracted to wood that has been softened by rot. Wood under a roof leak can become infested.

Watch out for wasps and hornets in attics. They have a nasty sting and some people are allergic.

In old house attics, there are often attic windows. Typically, older house attic windows need maintenance. Window glass is often loose or partly missing and sometimes the sashes are rotten.

Particularly in older houses, chimney problems are often found in attics because of restricted access and lack of maintenance over the years. Sometimes, your home inspector will find an old tin pan or bucket alongside a chimney under a chimney flashing leak, for example. While your home inspector is in the attic, he is likely to make a mental note of where the chimneys are located. He will want to remember to check interior walls on the second and first floors later on for former stove hookups.

During the inspection, it is not unusual to find several separate attics particularly in older houses. Your home inspector should inspect the interior of all of the accessible attics.

The next place your home inspector is likely to inspect is one of the rooms adjacent to the attic access.