What paint or sealant is recommended?

[rcm1201]

I live in South Louisiana where it is really hot, humid, and rainy. Just finished building the coop, looking for suggestions on what to use for paint or sealant to protect the wood. Also, do I need to paint everything, even the inside of the coop? Will poop rot the bottom of the coop without paint?

 

[nuthatched]

Paint all the osb with outdoor paint, and anything not sold to be outside in the elements.

 

[Captain13]

I used a product called Ready Seal. It is a mineral oil based sealer and really soaks deep in the wood. Unlike Thompsons and many other sealers it does not use paraffin so it won’t flake off after a year. I saw a demonstration where a 2x4 end was put into a gallon of Ready Seal and within minutes, it had wicked several inches up the 2x4. I stained a fence with the Natural tone 3 years ago and it still looks like it was just done. I used the coffee stain on my coop and run. The mineral oil odor was gone in about 24 hours. It really repellant water, is easy to apply (I used a sprayer to apply) and you don’t have to worry about overlapping coverage lines. Overlaps or brush/roller/sprayer mistakes blend together within minutes so the finish is smooth with no lines. Attached are pictures of the coop with the stain/sealer