Knob-and-Tube

Knob-and-tube wiring is so named because of the porcelain fittings used to support and insulate the conductors from the timber components in the home. The knob holds the wire away from rafters and joists, while the tubes are inserted into holes bored though joists and studs to protect the conductor and its rubber insulation.

Remote Distribution Panels

Although this topic is covered in other areas, because the emphasis is on safety, it's important to review.

The purpose of bonding is to ensure the electrical continuity of the fault current path, provide the capacity and ability to conduct safely any fault current likely to be imposed, and to aid in the operation of the over-current protection device.

Service Drop

The service drop is the overhead service conductors located between the utility electric supply system and the service point.

The service-entrance cable SEC (blue arrow) is a line of service conductors (white arrows) located between the terminals of the service equipment (main disconnect) and a point usually outside the building, clear of building walls, where they are joined by a tap or splice (orange arrows) to the service drop or overhead service conductors (red arrows).

Plumbing Vents

Depending on location, there are primarily two different types of plumbing vent flashing. The most common in northern climates is the neoprene or metal boot. In Florida and in many other southern states, a lead flashing, which also protects the plastic vent pipe from ultraviolet damage, is more common. The stack vent is provided for the waste stack. The stack vent is the extension of a soil or waste stack above the highest horizontal drain that is connected to the stack. This is the main commonly-observed pipe that is observed penetrating the sloped roof surface, and it may also be visible in the unfinished attic space. This is an inspection image of a stack vent pipe penetrating the roof covering surface.

Chimney Flues

While the inspection of chimney flues is a highly specialized procedure, any obvious deficiencies in the flue should be noted. In particular, pay attention to flues that are damaged, collapsed, or show signs of previous chimney fires. Extra care must be taken when inspecting chimney systems that are being used to vent fossil-fuel appliances, such as boilers, furnaces, water heaters and manufactured fireplaces, as any deficiency in either the liner or the chimney structure could be a potential fire starter, or could allow carbon monoxide into the habitable space within the home. It is now required that any traditional flues being used as vents for these appliances be fitted with continuous metal flue liners to ensure that no noxious gases can find their way into the home. Compliments of InterNachi

Vent Problems

As with any other system, roof venting may have been installed incorrectly, may not have enough area, may have been rendered inoperable by changes to the home, or may have been badly modified by the homeowner in an attempt to save energy. Such problems include:

Roof flashing are at least as important as the roof covering itself. A covering can be brand new, but unless the flashing are in a similar condition and properly installed, the roof is going to leak.

How to on gutters what to look for