When inspecting the attic, look for vent stacks that terminate in the attic area. (See FIG. 9-1.) This is a violation of the plumbing code, a condition that should be corrected. The vent stack should extend through the roof so that the sewer gases can discharge to the outside. While in the attic, also look for ducts. Whether they are air-conditioning ducts or ducts from an exhaust fan, they should not have any open joints. (See FIG. 9-2.) All open joints should be resecured. Sometimes the exhaust fan from a bathroom discharges its moisture-laden air into the attic. This is undesirable because the moisture can cause condensation problems. The duct from such an exhaust fan should be extended above the roofline so that the exhaust is discharged into the atmosphere. Also look for open electrical junction boxes and makeshift electrical wiring such as extension-cord wiring and “pigtailed” hanging light fixtures. These are electrical violations that should be corrected.
It is important to check the underside of the roof for signs of past water leakage and, if the structure is inspected during a rain, current water leakage. Water stains can show up on the sheathing or roof rafters and appear as dark-streaked discolorations on the wood. Sometimes there is a separate masonry chimney for the fireplace and a prefabricated chimney for the heating system. Joints vulnerable to water leakage are those between the chimney and the roof and between vent stacks and the roof. These joints should be checked for leakage. Water leakage through joints is a relatively minor problem and can usually be corrected by sealing the joints with an asphalt cement.
Of particular concern is the joint between a prefabricated chimney and the attic floor. (See FIG. 9-3.) According to building codes, there should be 2 inches minimum clearance between the chimney and adjacent wood framing. The clearance is a fire safety measure because wood, which normally burns at temperatures between 400 to 600°F, can ignite spontaneously at a reduced temperature of about 200°F if it has been exposed over the years to temperatures between 150 to 250°F.
If your house has a prefabricated chimney, check the clearance between it and adjacent wood framing. While the clearance space around the chimney prevents a problem, it also creates one because the open space around the chimney generally runs from the boiler/furnace room to the attic. If a fire should develop in the boiler/furnace room, the open area around the chimney will act as a flue and draw the flames up into the attic where they can very rapidly consume the structure. Fortunately, the condition can easily and inexpensively be corrected by blocking (fire-stopping) the opening with a noncombustible material such as sheet metal.
If the house has a fireplace or wood-burning stove, check the section of the chimney that is exposed in the attic. Look for soot or a creosote buildup around the joints. This indicates cracked or open joints through which the exhaust smoke is seeping into the attic. This problem exists more often with chimneys that have unlined flues than those with lined flues. This condition is a potential fire hazard that must be corrected. Record this fact on your worksheet.
Fig. 9-3. Open joint between chimney and attic floor-a potential fire hazard.