Can someone tell me what the plywood panels are fixed to and how. Screwed into wooden frame? Do the panels butt up to each other creating the black line? Or has something been used to created the linear effect?
Welcome to the Bunnings Workshop community. Thank you so much for joining us and sharing your question about the plywood ceiling.
The black lines or gaps you are seeing on the ceiling are actually the frame of the roof that has been painted black. The plywood panels are then cut and screwed in place with the painted timber visible. Several Plywood Sheets are suitable for such a project, it depends on how big the ceiling is.
There are a few types of Plywood, some have very noticeable knots and swirls, others are very plain and have no lines or knots in them. I suggest a thickness not less than 12mm to prevent bowing or warping. However, I recommend consulting with your builder to make sure that the one you choose is suitable. If you are planning any projects in the house, please keep us updated.
Let me tag our experienced member @JoeAzza for his recommendations.
If you need more advice or information, please let us know.