Framing Details for Wiring

The design and installation of the entire wiring system is usually regulated by a provincial electrical code, all of which are closely modelled on the Canadian Electrical Code published by the Canadian Standards Association. The provincial codes usually require that the installation be done by a licensed electrician. Owners are advised to check with the local authority when planning a wiring installation.

Figures 157 and 158 show the typical arrangement of electrical service entrance equipment. The limitations for drilling structural members for wiring are shown in Figure 159. The amperage of the electrical service and the number of circuits and outlets installed should take future needs into account. Modern house services usually require 200 amps.

Figure 157

Typical arrangement of service entrance

Figure 158

Service entrance equipment

Figure 159

Drilling of structural members for wiring

Wiring is usually started after the house has been enclosed. The initial phase of wiring is called roughing-in and includes the installation of wiring and the boxes for the switches, lights and outlets. Figure 160 shows some typical electrical equipment.

Figure 160

Typical electrical equipment

Roughing-in is done before the inside finish is applied and usually before insulation is placed in walls and ceilings. Lighting fixtures, switches, outlets and cover plates are installed after the interior finish and painting operations are complete.

Location of Switches and Outlets

Plan the location of switches and outlets carefully. Electrical boxes located in insulated ceilings and exterior walls must be sealed to prevent air leakage. Solid plastic airtight electrical boxes are recommended for use in exterior walls and ceilings.

Switches are typically located just inside a door opening so that they may be easily reached when the door is opened. Switches may activate a wall outlet for a table or a floor lamp or ceiling or wall lights. Locate switches about 1.4 m (4 ft. 6 in.) above Housing by Design: Living Spaces for more information about accessible placement of switches and outlets).

Three-way switches can control power from more than one location. For example, a living room light could have a switch near one entrance and one at another door leading to the kitchen or to a hallway.

In houses with two or more storeys, three-way switches must be provided at the bottom and at the top of the stairway to control stairway lighting. Three-way switches are required for stairs to finished basements, but not for unfinished basements. the floor, or 1.2 m (4 ft.) above the floor for a person in a wheelchair (see About Your House fact sheet Accessible

Source : Canada Mortgage and Housing Corporation (CMHC)