159 Drilling of structural members for wiring blocking caulking sealant or rubber grommet air barrier membrane truss chord air barrier system and vapour barrier strapping drywall ceiling finish surface mounted receptacle pendant fitting recommended to reduce heat build-up double studs at door opening switch box to door framing with two 100 mm (4 in.) nails wires stapled as shown metal protection plate fixed to edge of stud member when required 30 mm (11⁄4 in.) holes drilled for wires Note: When holes are drilled closer than 30 mm (11⁄4 in.) to the edge of a stud, metal protection plates are required. holes drilled in double top plate to ceiling fixture 1 400 mm (4 ft.–6 in.) holes drilled in studs for wires outlet boxes fixed to studs with two screws or nails holes for in bottom plate and joists to service panel