Tongue & Groove on APA Trademarked Plywood Panels

APA trademarked plywood panels have a tongue and groove (T&G) profile on their two long edges. See APA trademarked panels.
You can see an example of this feature in the photo opposite, with exposed T&G plywood roof sheathing in the recently built design office for US architects, Rogers Kranjnak.
Technical Notes:
- The use of tongue & groove removes the need for support (blocking) under adjacent panel edges to prevent them from deflecting independently of each other when load is applied.
- The material removed to create the tongue normally reduces the width of the panel by 12.5 mm (1/2″), therefore the net width of tongue and groove panels is typically 1206mm (47-½”).