Yesterday's pic included a sneak peak at the first floor joist. Here's a better look. (Note: the end isn't trimmed to length yet; more on that later.)
I-beams are really strong and allow long spans without column supports. This is a key feature of my building. I want the whole area open to move around trailers for example. Did I mention the second level? This building is a two story. The upstairs floor must be strong. These beams will also support knee walls which in turn support rafters and much of the roof as well. I explored commercial I-joists but was so unpleased that I engineered my own instead.
They are laminated with half-inch plywood webbing. Joints between long 2x4's and 2x2's are lapped and staggered so all members reinforce each other. The tops work in compression so they're just nailed together every foot or so. The bottoms work in tension so they're also glued together. Calculations predict negligible deflection even under heavy loading. They may be over kill for my application but better safe than sorry.
A lot goes into each beam. One and a quarter sheets of plywood. Sixty feet of 2x4s. One hundred twenty feet of 2x2s. Probably about ten ounces of wood glue and a hundred nails. Some assembly required.
The fewer joints, the stronger. So long boards are important. Take 2x2s for example. Normally they come in eight foot lengths. They also tend to be finger joined, sometimes multiple times. No thanks. Turns out, it pays to go out in the lumber yard and look closely to find longer 2x2s available in 12, 14 and 16 foot lengths. They come in not so convenient two-packs called 2x4s. Some disassembly required.
It took a couple days to build the first five joists. Moreover, at nearly two hundred pounds each, getting them up where they belong was non trivial. Once again my father in law helped and we worked out a safe and effective process. It was a good exercise in team work not to mention a good deal of applied physics and geometry. First we got the five joists up on one end of the building. In my excitement the day before I neglected to trim them to length while on the ground (easier - duh) so I got to trim them up high.
To get them up there we first walked one end up a pair of ladders. Not exactly easy but not as bad as you might at first think. Each end weighs half the total and that's split between two guys.
With some hanging over each was then laid flat. A little counter weight also lightens the second end. Then we walked that up ladders on the adjacent wall so it laid across a corner with the second end supported by one of those handy scaffolds I mentioned earlier.
From there we stood each back upright and slid it across scaffolding until it spanned both sides. Rinse and repeat for the others butted up adjacent so they can't go anywhere. Then we set them out into position beginning with the furthest of the group. In computer terms it's known as a LIFO (last in, first out) buffer. (Somebody has to keep Bob Vila and Norm Abram on their toes.)
The rest were moved out and set in position one by one.
Five down, fourteen and a half to go. This was a nice milestone. With decking on those beams (soon) it can become a work surface. The remaining joists can just be built right up there. Moving them out into place is nothing compared to hefting them up!
The convenience of not lifting beams up to the second level definitely outweighs (groan) extra time and attention for safety working up high on a structure that's a little wobbly at this point. After working up there all day I notice at night that it's like I've been at sea and have to get my land legs back. All the effort is paying off though, slowly but surely. Now the thirteenth beam is set. Only six and a half more to go!
Oh, I had to laugh. After setting the last group of three beams this afternoon I walked over from rear to front to come down. Before I got to the scaffolding and ladders a tree branch whacked my head. Turns out a platform fourteen feet high makes it real handy for trimming branches. That big ole maple (see Day 33 for a better pic) is a story itself ... for some other day.
The nineteenth beam was set today. Yeah!
A little planned rework remains. The end beams are not permanent in those locations. They gave me corners to measure squareness of the floor. The 51.6' diagonals showed 1" difference. Pretty good really but I racked the wall tops anyway.