I think one of the joys of beekeeping is the woodworking that is required. I'm learning that bee's really LIKE wood and all the componets that go along with that. If plywood is used with the pine framing, with the correct joints and glue, painted and protected from the elements (mainly moisture) then even 1/4 will lay straight and last for years. yes...I even like telescoping covers for a nuc......protects it and you can use it over and over for many years. While I dont have many beehives, I've built many other things over the years thats sitting outside and if done right.....they last. Of course I'm not building hundreds of these so I dont have that worry.