I am towards the end of a bathroom remodel project and am planning on installing a walnut plant ceiling. I have some old rough-cut walnut about an inch thick that I am thinking of resawing down to 5/16th and putting an 1/8 in chamfer edge on the sides and not doing tongue and groove. Do I need to worry about board movement with moisture in the bathroom? I did install a large CFM exhaust fan knowing I was planning a wood ceiling to help cut down on the moisture in the bathroom.
Also, was looking for thoughts on the best way to finish the walnut boards. I have been looking into Rubio Monocoat but also want something that will be fairly low maintenance that I won't have to redo every couple of years. Should I just use linseed oil then use poly?
Thank you ahead of time for any input you might have.