These vents can be found on pitched and flat roofs and are available in both round and square hood styles. Normally, there are no problems with these types of vents. However, the joint between the vent and the roof is vulnerable to water leakage. Even though the joint might look okay from the roof side, it is best to check the vent openings from the attic periodically. If there is leakage, it will be noted by water stains on the roof deck in those areas. Water leakage around the joints can be easily corrected with asphalt cement or a suitable caulking.
Access to a flat roof from the interior is provided through a roof hatch. Don’t be surprised if you find a roof hatch on a house with a pitched roof. In some older and larger structures, they were installed as a means of easy access. Roof-hatch covers should be checked to determine whether they are operational; they should be. I have found that in about 30 percent of the cases, the hatch covers could not be opened. In all probability, during reroofing or maintenance, asphalt cement accidentally or intentionally sealed the hatch-cover frame. If this condition exists, it should be corrected. Usually, the hatch cover is constructed of wood and is covered with either sheet-metal or asphalt roll-roofing. Of particular concern is the integrity of the waterproofing cover. There should not be any cracked or open joints. The wood framing should not have any cracked or broken sections.
Fig. 3-7. Plumbing vent stack terminating near window. If the window is open, the discharging sewer gases can be blown into the house.
Skylights are installed on a structure to provide daylighting and in some cases ventilation. The newer styles are prefabricated, with aluminum frames and plastic or glass panels or domes. Skylights can be found on pitched or flat roofs. These units should be checked for cracked or broken panes and signs of leakage. The leakage can be checked by inspecting the interior area below the skylight. If there are leaks around the skylight, you’ll note water stains on the wall or finished ceiling in those areas. The skylights found on older flat-roof homes should be carefully checked for corroding frames and cracked and broken panes. Quite often the frames have corroded through and provide no support for the panes. This condition should be marked on your worksheet, because these skylights require complete rehabilitation.
Although roof-mounted TV antennas were quite common when the first edition of this book was written, for the most part they have been replaced by cable television or dish antennas. Nevertheless, they can still be found on many houses. Some TV antennas are strapped to the chimney for support. This means of bracing the antenna is undesirable because repeated twisting action on the antenna from strong winds can cause stresses on the chimney that can in turn result in cracked mortar joints. When you see a TV antenna strapped to the chimney, look carefully at the joints. Sometimes the antenna is supported on the roof by means of guy wires anchored to the roof deck. When inspecting the roof, check the area around the anchors for deterioration of the roof covering. Sometimes the guy wires are strapped to vent stacks. This practice is undesirable because in a strong wind the movement of the antenna can cause the joint at the base of the vent stack to crack. I have also run into a situation where a homeowner inserted the TV antenna mast-down into a vent stack to secure the antenna. If you see this situation, make a note of it so that you can remove the antenna after you take possession of the house. Finally, look for a ground wire that connects the antenna to a metal rod embedded in the ground. According to the National Electrical Code, this wire should not have any intervening splices or connections. The TV ground wire does not protect the house from lightning. Its purpose is to protect the television set in the event of a lightning surge.
Although there are about 90 million lightning strikes each year in the United States, most homes don’t have a lightning protection system. If a house has one, you will notice pointed metal rods projecting up above the high points of the building. These rods are connected to stranded cables, which are then connected to at least two grounded conductors. Of particular concern is whether the connections are properly bonded and if the system is properly grounded. Because of the destructive power of a lightning strike, the integrity of the system should be checked by a company specializing in lightning protection.