The Ontario Building Code | Edge Support
9.23.15.6. Edge support
(1) Except as permitted in Sentence (2), where panel-type roof sheathing requires edge support, the support shall consist of,
(a) metal H clips, or
(b) not less than 38 mm by 38 mm blocking securely nailed between framing members.
(2) The supports referred to in Sentence (1) are not required when tongued-and-grooved edged panel-type sheathing board is used.