Important note: Greg mentions throughout the video that he cannot provide lumber sizes and recommends consulting an engineer for your specific location.
Ceiling joists
The video doesn't specify the lumber size used but mentions 2x8 as an example that might work for a 15 feet span. It is recommended to consult an engineer to determine the appropriate size for your location.
Roof framing
Greg mentions that trusses can be difficult to install without a crane. The video shows a method for building a roof framing yourself. Blocking is used to support the rafters and plumbing or electrical wires can be placed in the blocking area.
Wall design
The video showcases a design where a wall runs through the center of the house to support the rafters and the wall above. This design was commonly used in older houses.
Rafters
The rafters lap over the ceiling joists and blocks. The tops of the blocks are shaped for better nailing the plywood sheathing.
Gable wall
The video demonstrates building a rake wall or gable wall with a rafter tail at the bottom. Straps might be required to tie the building together.
Fascia board
The fascia board is connected to the lookouts, which are 2x4 boards. The video shows a 45-degree angle break in the fascia board, but it can be done at a 15-degree angle.
Roof sheathing
Roof sheathing should break and be staggered on top of the roof rafters. The video mentions some engineers might require a minimum size piece of sheathing in both directions.
Additional tips from Greg
If you are not sure about something, ask an engineer.
Make sure to check local building codes before starting any work.