Painting Particle Board Roofing in a Screen House?
 

Hello all! Last summer we as a family put in some collaborative sweat equity and came out with a great screen house in the back yard. The roofing was done by a local contractor who chose to use particle board as the base. So now, we look up and see bare particle wood and are starting to think about painting it. I'm thinking about the variables first:

The real question: What is the best / proper way to paint particle board?

• I want to keep the beams / joists unfinished (so spraying is out)
• It is an outdoor setting
• It's a ceiling / roof (if any gloss should be considered for light reflection)
• Will I have to sand any glue / sealant on the board first?
• Do I have to prime or will your suggested paint be a one coat type?
• Can the imperfections of the particle surface be hidden /subdued in any way (hide the bumps)?

Spray is with an exterior primer followed by a good quality exterior paint.

Not painting beams
 

I should have added in my post:

I want to keep the beams / joists unpainted, so spraying is kind of out.

Your going to have to prime it first with a sealing primer then paint it. Those grade marks are just going to blead through if you skip that step.
Keep in mind painted OSB looks like poop.