Inspecting an Attic from the Inside Out

By: Cliff Steelman

The attic is one of the most important areas of the house to be inspected. Here’s why, along with a few tips to help ensure that your attic inspections are thorough and complete.

To understand the importance of an attic inspection you must first understand the purpose of the roof system. That purpose is very simple: to keep water from entering the building. To do its job, the roof must be water proof. Most roofing materials are also moisture proof.  Water and moisture are the most common causes of damage to structures. So not only must the roof be water-proof but the building must also be properly vented to allow moisture to escape the structure. Some homes include a series of vents working together to provide adequate escape routes for moisture. The best venting provides a draft effect, such as a combination of soffit and ridge venting. (Hot air rises exhausting through the roof vent and pulling fresh air into the attic from the soffit vents.)

Inspecting from the Outside In
An attic inspection begins on the outside of the house. You should be looking for venting from outside of the home and for signs that might indicate whether the venting is adequate. Some exterior signs of inadequate venting are undersized vents, mold or mildew around the vents, peeling paint on soffits or gables and delaminating or water-stained soffit material. You should be looking for signs that exhaust fans, chimneys and sewer vent pipes from within the house vent to the outside and for any type of sags in the roof sheathing or framing.

Inside the house some indicators of inadequate attic venting are dark spots on the ceiling, especially near the exterior walls, mold or mildew on the ceilings, especially inside close areas such as closets or bathrooms. Once the exterior and interior of the house have been thoroughly inspected, you are ready to look inside the attic.

Once inside, slow down and make an effort to take your time. There is a lot to look at. You don’t want to have to make a second trip to the attic to check on some component you missed. Be systematic in your approach. The condition of each component inspected must be accurately noted in your written report.

Before opening the attic hatch look around for staining which may indicate air infiltration from the attic to the living space. Do not enter an attic unless there is a walkway and adequate head room. You must report on how you inspected the attic. If you inspect the attic through an opening because there is no walkway, that must be noted in your written report. If this is the case, it is critical that you also note from what vantage the inspection took place (i.e. garage, master bedroom closet, stairwell).

Once inside the attic, look for light coming from outside, at the venting you noted while outside the home. If light is not visible at the vents seen from the outside of the house they may be blocked or not properly installed.

There are several indicators of moisture or water which can be readily seen from inside the attic. Look at the color of the wood: dark colored wood may indicate moisture and either a past or present lack of ventilation. Look for mold or mildew growing on the underside of the roof or framing members. Look for rust on nails or dark rings on the wood around nails. Look to see that all sewer vent pipes are connected and penetrate the roof. (Sewer vent pipes connect directly to the sewer system and if not sealed properly, can send immense amounts of moisture and methane gas into the attic.)

At a minimum, exhaust fans must terminate close to a serviceable vent and preferably should vent outside the building. (Kitchen exhaust fans can become a blow torch to the attic in the event of a cooking fire.) Look closely at all chimneys for tight connections and to ensure that they terminate outside the building. (A loose or open flue or chimney in the attic will vent immense amounts of water and combustion gases into an attic.) Count the chimneys: there should be the same number going through the roof as there are fossil fuel burning components observed inside the house.

The framing should be evaluated for size (is it adequate for the span?) and inspected for cracked, broken or deteriorated framing components, as well as water stains. Insulation should be evaluated for type, form and approximate “R” value (air flow resistance factor).

If there is an indication of moisture or water in the attic the inspector must attempt to locate the source. Excess moisture can come from many sources. Lack of ventilation is one of the most serious but other sources of water vapor can come from combustion flues which leak into the attic, exhaust fans or sewer vents which terminate in the attic. Even large fish tanks and plants grown in the house can be contributors. A lack of proper ventilation or a missing vapor barrier in the crawlspace under the house can also contribute to moisture throughout the house and in the attic.

Your thorough inspection concludes with a complete and thorough report, including written recommendations to the home buyer to seek expert advice to address any deficiency noted before the transfer of the property.

Cliff Steelman, Sr., CHI has been a full time home inspector for six years. Cliff lives in Prosser, Washington and is a graduate of the Home Inspection Institute of America.