I have a question about purlins. I am building a 1 1/2 story post and beam structure and the 3x6 purlins are designed to lay flat and nail on top of the rafters instead of on end like a stick framed roof. I like they way they look in a finished room laid flat and also the additional head room as opposed to laying them on end and nailing them through the rafter.
My question is has anyone had any experience with sagging over time whan they are nailed flat with the roof decking over top?
