Starting work on the subfloor

I decided to take the 4th of July week off from work to get back to work on the house and make up some time. With only three days vacation for nine days off, it seemed like a good stretch to accomplish something. But it was going to be hot. But that's what we get for working in June and July. 

I removed the old a/c disconnect box and pulled the wiring into the crawl space. I also had to re-route the dryer vent to exit into the front of the house, in the area between the new addition and new front porch. This is a convenient location and also a much shorter run than the old one. Hopefully this will result in less lint buildup.

The lumber package for the additions subfloor and the porch framing arrived about two weeks ago from 84 Lumber. We ordered everything except for the double 2x10 band beam that is used to go against the house and hold the joists running across the foundation. I wanted to select these myself to make sure I got nice straight lumber. Off to Lowe's we went and selected four 12' 2x10's and two 10' 2x10's to make up the double beam. 

The 23/32" Advantech plywood I'm using for the subfloor actually measured around 3/4". I had removed enough of the existing house siding and tar paper underlayment where I could see the existing plywood subfloor. The subfloor on the existing house is 1/2" plywood. We made marks 3/4" below the top of this subfloor and snapped a chalk line to mark the top of the 2x10 band beam. 

We nailed up the first layer of the beam along the string line. We used just enough nails from the new Paslode framing nailer to hold it in place. Then, I cut the next row of the beam to stagger the joints mid way between the first row and nailed those in place. 

Our plans called for using 5/8" through bolts, every 12" along the length of the beam, staggered top and bottom of the beam. But before drilling the holes, we laid out the joist hangers, so the bolts wouldn't interfere. The joist hangers were installed from the back of the addition to the front, so that the water line and electric for the pier coming out of the house were between joists. Going the other way would have resulted in a joist landing right where they came out. 

Each of these joist hangers had eight 10D nails to install. Since my framing nailer wouldn't work, I got a good workout nailing 27 joist hangers!

Now for the bolts. I got out my old 1/2" hi-torque drill to drill these 5/8" holes. We'd be going through 4-1/2" of material so needed a good drill to do the job. And when I say old drill, I mean it! This drill belonged to my Dad, and it belonged to his Dad. I'm sure used on countless projects, I get to use my grandfathers drill to bolt my house together. The last time I used it, I was drilling holes through pier pilings to make a walkway and nearly broke my wrist. As i was drilling, the bit got hung up, but the drill kept going. The cord wrapped around my wrist and I couldn't let go of the trigger. Thankfully before doing any real damage to myself, the cord pulled out of the handle, shutting the drill down. So, today I wired up a new cord inside the handle and with the knowledge of potential bodily harm, off we went. Or should I say, off Amy went. She ended up drilling nearly every hole in the beam. And got a good workout doing so. And did I say this drill has no reverse? You have to be careful not to drive the auger bit in too far, as it can get nearly impossible to pull out and clear the wood chips. 

Amy stayed outside while I climbed into the crawl space with a wrench to install the through bolts. She installed them from the outside, I added a washer and nut and held it from turning while she tightened it down. The whole house may fall down, but this beam will never separate from the house!

Now to get to the quick and easy part, installing the joists. I had to trim every joist by a couple of inches, so I brought out my Hitachi 12" sliding compound miter saw, set up a stop to index the 14' joists and cut each one the same. To install the joist hanger end, no nails are necessary. We just moved them into position, pressed them tight against the beam, and hammered them downward. They snapped into place and that was that. 

For the other end, I had previously made marks every 16" and a nail was toe-nailed from each side into the sill plate. Using the framing nailer made quick work of this. 

Once we came to the crawl space, things were a little different. I had to install a header over the crawl space opening to carry the load across it. Similarly I also had to install a header over one of the crawl space vents as the load from a front wall girder truss will be directly above this. I didn't realize this at the time, but once we had the truss layout design, I realized my vent was in the wrong location. 

The headers were made from 1-3/4" LVL's. That with the 1-1/8" rim board make up the header. Joist hangers were used where the joists ran over the openings. Otherwise, it was business as usual installing the remainder of the joists. 

Finally, we installed the 1-1/8" rimboard on the ends of the joists. The 37' long wall had a rim board from back to front, and then there was the 3' short wall on the existing house side that needed a rim board. This was toenailed in place. A nail in the top and bottom of each I-joist (staggered) was also needed. 

At that was a day's work! It was getting late and a perfect spot to stop. Tomorrow we'll get running on installing the Advantech subfloor. It should go pretty quickly. Other than taking plenty of breaks due to the heat!