Floor System Joists and Girders

The floor system for the first floor is almost finished. I’ve been working on it for about a week and a half because I have been fighting the rain. Every time I get busy, I’m held up by rain. Plus, I’m Mr. Owner Builder – Do it Yourselfer on this, so I am handling all of the work on my own.

I’m using 3-ply 2×12′s as my girder, glued and nailed together spanning the 24′ and supported at 8′ intervals. It’s a little over engineered, but I wanted a strong floor. I’m using #1 pine 2×10′s as my floor joists with the longest span at 13’6″. I wanted the house to be closer to the ground, so I’ve opted to hang the joists from the girders instead of resting on top of a girder. The building code calls for joists to have a 18″ clearance and girders to have a 12″ clearance in a crawl space. So, I made my girders 15″ so I have 18″ to the joists at the very lowest point in the crawl space.

The joist hangers are Simpson Strong-Tie LUS210Z 2×10 joist hangers. They require 10 nails in each hanger, so the bulk of my time has been spent banging these in. There is a little trick to these that I didn’t know, but quickly figured out. There is a cut out piece of metal that is bent in and angled toward the direction of your girder. Once you line the joist hanger up, you can easily hit this metal piece and it drives it into the girder as a sort of temporary staple. It WILL NOT hang on for long if you’re hanging joists on both ends. As soon as you knock the other end, your opposite side will pop out with the smallest vibration. I knocked these metal staples in, then nailed in the top two nail holes on either side of the hanger then went over to the other side to line up the joist on the opposite end.

I’m at my wits end with the rain because I put that 6 mil plastic down, so if water gets in there it will just puddle up and have nowhere to go. But, once I put the floor down and screw everything in I am going to put some plastic over it all, then it can rain all it wants. I’ll just get frustrated when I start working on the second floor.  Here are some pictures of my progress with the floor system.