Just setup a new workshop in my barn and have a 7x7 opening that needs a door. I've loaded up my new table saw with wax but it's just a matter of time before the elements gets to it.

I'm planning to build a single sliding door from 6/4 poplar using lose tennons and mortises. I have 3/4 inch t&g pine on the barn siding that I'll use for the panels and plan to put some divided light windows at the top.

Am I going too thin and should go with 8/4 stock instead of the 6/4? Getting the 8/4 in 8 foot lengths might be tough.

After some planning I should be shy of 1 3/8 thick for this door. Eventually I'll heat the shop so want to make sure this lasts.

Any guidance?