Brian, and others, I don' want to contradict you all, but let me share my experience.
The first year I had my montana canvas wall tent I followed the instructions and set it up and wet it down. That spring, summer and fall were uneventfull, until the last two days of hunting season. I had to go home but my buddy stayed in camp. there was an inch plus of rain that fell in 3 or 4 hrs. it leaked at the seams, then 10'' of snow fell, my friend bailed out when it started to snow. I went back in the snow to check on my camp. All was OK but a little damp.
I was sure that I needed a cover for the tent. My other buddies with wall tents asked me about the preperation (wetting it down). Then suggested that I may not have treated it properly. I went out on a limb & set it up again just before a rain storm. ZERO LEAKS! my tent just needed to shrink a little.
Brian, ask Preacher or Burr (Craig) if his tent leaks while he is hunting.
I now use a fly in front of my tent to make a porch, and have considered a second layer of canvas above my tent for an additional layer of shade in the heat of the summer.
Oh yeah, the screen mounted to the frame at the door is an abosolute necessity. Last thing, I tack down my left door to keep my stove safe, and stack wood behind it.
Best of luck!
Rich
One last thing Joe is a great guy, you can't go wrong working with him!!