House Building Saga, Part the Third December 9, 2009Posted by ficial in house building.
It was a busy day yesterday between house construction during the day and pottery glazing in the evening.
Work went a bit slower than hoped yesterday. To deal with slight unevenness in the foundation wall height and footing height, the base of each post has a little block of carefully sized wood under it. These blocks were all carefully measured with a laser transit, cut, and labeled. Two of them incorrectly. So, the big task in the morning was jacking up the two center posts (all of which were already supporting beams, luckily not pegged in yet) and swapping the blocks under them. The pros handled the mechanics of that, but it took a lot of discussing and planning and generally ate up an hour or so in the morning.
Once the problem and solution were determined, Amy and I stayed out of that mess and focused on pegging the good joints. In the late morning Craig (our general contractor) showed up and joined his crew in putting the next big beam in place. The house has three really large beams – 6×14 by 16 feet long. We’d planned on using an electric lift to get them in place, but the crew just muscles them up. Today was a little more sane than last time, as there’s now actually some staging in place – http://www.flickr.com/photos/plussed/4170417101/in/set-72157604535245968/. This manual lifting seems to be working well enough that we just called the rental company and had them take back the electric lift.
A few more beams went up after the big beam, so we now have 9 posts and all the beams between them, making a 2×2 grid viewed from above. Once that was set we spent a lot of time truing up the main, central line of the house. This was complicated by having a few of the tenons on the posts slightly mis-set, so the tenon would be hard against the inside of the mortise but the beam end would still be 1/8 inch from the post. One of these we fixed by re-pegging the tenon (the tenons on the post are separate pieces of herd maple pegged into place – http://www.flickr.com/photos/plussed/4164614764/in/set-72157604535245968/). The others were left as is. For the rest of the project we’ll be checking depths before hoisting and placing and trimming as necessary to get a tight fit.
The truing process used a fascinating technique/tool/trick, called a spring board, which I suspect is well known in the carpentry trade, but I’d never seen it before. Basically, you get a long (16 feet, in our case) 2×4 and lay it at a ~45 slop against the thing to be pushed – a central post in our case. Then fix one end, doesn’t matter too much which. Then press the center of the 2×4; push or step or pull on the spring board so it bows. While it’s bent someone else fixes the free end – drive a stake against it, or affix a block or whatever. Then release the spring board and it will push with a LOT of force. Generally it will stay somewhat bowed still. If you need even more force, pull up on the center of the board to straighten the 2×4. If the ends of the spring board are firmly fixed you can also reverse this process to pull a load. Over all, it only gives you an inch or so of horizontal movement, but at a tremendous mechanical advantage and assisted by the elasticity of the 2×4.
So, we got the center line trued up, then strapped (http://www.flickr.com/photos/plussed/4167020955/in/set-72157604535245968/) to pull the joints tight, then we pegged all the joints and braces (thus establishing triangles to hold the frame rigid in that trued position). The pegging was more of the same kind of work we’d done already, but this time 15′ in the air. This was the first time in the project I’d climbed up the second floor. It definitely kicked in a bit of my height-nervousness, but it was also very cool.
At the end of the day we packed things away good and tight in anticipation of the storm on Wednesday.