
4' on centers...you are going to have a tough roof to walk without being super careful.
Is the space below a conditioned space? Open rafter/framing designs are tough when it comes to humidity and condensation concerns.
If you are conditioning it, you are going to want to beef up the framing and run plywood.
You will definitely need to beef up the structure to assist with that span and don't under sell on the plywood. Go with 5/8" and make the roof solid.
I’m currently tearing a horribly made roof off an old house I recently purchased. I will be putting new trusses (4/12) & metal on the trusses. The trusses will be 4’ OC. Will it be a mistake not laying sheathing & just doing purlins every 2’? I dont think I have many options since the trusses are 4’ OC instead 2’ OC.
Can the metal withstand a persons weight without sheathing?
Do I need underpayment?
What type of insulation?
The house is a single story and has a full sized basement. It will be air conditioned (?). So I’ll probably want to run 4’ 2x’s between the trusses so I can mount plywood?