We got Advantech ¾" decking for the floor, 2x6x16' for rafters and a variety of 2x4 and 2x6 lengths for framing. I had forgotten how heavy wood is compared to the metal that we had built the house out of. Quite a difference! The Advantech was 75lbs per sheet. It's very dense with and infused with resin to help with waterproofing. No, it's not marine plywood, but it's also only ⅓ the price. We picked up all of the wood supplies from Fort Worth Lumber. Really nice people to work with and they carry a lot of dimensional lumber, plywoods and beams that you just can't find at the DIY centers.
After playing with the layout of how we wanted the decking to go down, we finally got started by rolling out some 30# tar paper. I know the Advantech does a great job handling moisture but I just wanted another layer of protection down to start with. This should also help with any creaking of wood rubbing against the metal joists and wire decking. Well worth the $10 worth we used.
We started laying out the sheets and screwing them down to the steel frame. I was pleased that the self-tapping screws we had picked up did a nice job of both drilling through the decking and tapping into the steel joists. Be sure you have a #3 phillips bit if you don't buy the big bucket that includes one. They drive much better with it than a #2. The tongue and groove edging on the decking fit very smoothly and made for a great, uniform seam. We put our cut edges against the wall side and left a factory edge for the middle of the floor. By splitting the difference on the middle beam, we were able to share it with the next sheet much like you would share a stud for 2 sheets of drywall. The 2 factory edges of decking also made a very nice seam where they met in the middle. It's good when things work as you planned!
What we didn't have any control of the width of the building as it's set by the length of the steel beams that connect the upright ends. As it turned out, we came up about 1 ½" shy of covering the floor with the 3 sheets wide. This was because T&G dimension is from edge of the groove to the edge of the tongue, which tucks inside the next sheet's groove. You end up getting 47 ½" coverage from a sheet, not 48" if you had used plywood. The problem with plywood we've found is that the edges curl up over the years as humidity soaks in. The T&G should hold nice and smooth in contrast. I was too cheap to purchase another sheet to cover the small gap so we ripped down a 2x4 and set it into the gap. Since everything is getting screwed down to the steel beams, I'm not worried about it shifting over time.
We had tried cutting the decking with our table saw, but it was just too heavy and we found it unmanageable in our primitive surroundings of the woods. A clamped straight edge and a skill saw did the trick nicely. It gave us a quick cut with a razor straight edge.
We took the opportunity also to move the supports in the middle upright on the tall side to make room for our door. I'll need to cut down the diagonal supports a bit and re-drill some holes in it but we should be able to reinstall as soon as we do.
Once we got a row of decking in place, I tacked it down and we moved to the next knowing we wouldn't bump anything out of place. The floor felt nice and solid when we finished and we turned our attention to getting the rafters up.
We got the other header made but we ran out of daylight and decided to quit for the night. We turned off the generator and sat down to enjoy the quiet for a bit. We took a walk up the trail where we had our wildlife camera positioned. We were really surprised to see that a couple of coyotes had visited as well as a group of deer in the middle of the day. Our raccoon friend as well but only at night. We also found some hog tracks back at one corner of the property so we moved the camera to that area to see if we could tell how many were moving through.