Pre-made Trusses
The jig as modified for the short trusses; notice the pre-cut components in the background and the long radial arm saw table for gang-cutting them |
A truss prior to removal from the jig; gussets have been nailed on |
Then I used the jig and two Pasload nailers to assemble the trusses. Without thinking, all four gussets were nailed to place only to find out later that one on each truss had to be removed in order to have access for nailing the trusses to the mudsill after the wall was raised.
Building the Wall
Trusses made from recycled lumber except for new OSB gussets |
Since the mudsills had already been installed, they were not available for nailing to the
The short wall upon completion |
The last section ready to raise; notice the 1-bys bracing the bottoms of the trusses for raising |
The plastic sheeting that was stapled to the mudsill on the day it was installed (first post on the short truss wall) was left in place under the trusses. Eventually, after the pressure treated wood has dried sufficiently and the roof shades the sill from the sun, the plastic can be cut away without worry about the sill warping due to uneven drying in the heat of the sun.
The concrete contractor placed the anchor bolts in the middle of the 10" wall so they ended up only a couple of inches from the inside edge of the 2 x 12 mudsill when it was cantilevered 4" outward in order to be flush with the stucco. I added an equal number of anchor bolts an inch or so from the outside edge of the concrete. The extra anchors at least fell in the
So much anchorage may seem like overkill but our location carries three types of risk: tornadoes, earthquakes and subsidence. We have tornado alerts every year, sometime several times, and actual tornadoes nearly every year. Seismologists say that the odds are pretty high for another major earthquake at the New Madrid fault near the Mississippi River in southeastern Missouri. If one should happen, the seismic waves will follow the gelatinous river floodplain to St Louis with the potential for major damage. Finally, subsidence from cave-ins of abandoned underground coal mines occur regularly in southern Illinois, including in Collinsville where a reasonably new school had to be razed a few years back due to subsidence damage. The old mine under our site is a little over 200 feet down and, even at that depth, we have to worry about subsidence.
Just like the other 15" exterior walls, the short wall will be insulated with rice hulls to an R-48. The 5" space between the tandem top plates will provide access for blowing the hulls into the wall cavity after the sheathing and drywall are in place.
The first set of top plates were nailed to the wall before raising. Consistent with common practice, a second set of top plates were necessary to bridge the joints in the first set and establish continuity and alignment. The roof trusses will rest only on the outside-most "top" top plate. Because of the pitch of the roof, there will be space between the inside "top" top plate and the trusses. Consequently, I used less-than-perfect salvaged 2 x 6s for the inside "top" top plate but bought new 20 foot long 2 x 6s for the all-important outside "top" top plate to which the trusses will be fastened.
The jig for pulling the measurement for the roof trusses |
Measuring for the Roof Trusses
Working alone, it would have been impossible to pull an exact measurement for the roof trusses without some sort of jig. One of the new twenty-foot 2 x 6s for a top plate was perfect for making a jig. I scabbed an extension to it and used it to span the distance between the front and the back walls. Beforehand though, I put a shallow saw kerf in one edge and tacked opposing keepers to the sides of the board in several places. After hoisting the 2 x 6 to the top of the walls and standing it on edge near the west end, I used a level to make the saw kerf even with the outside edge of the front wall framing and clamped the 2 x 6 to the middle wall to steady it on edge.
Then, to pull the measurement for the trusses, I hooked the end of the tape measure in the
The vertical lines on the 2 x 6 flush with the wall framing; notice that the variance between locations is only 1/4" (to see the lines better, click on the photo for blow-up |
I might say parenthetically that the technique for measuring just described is only one example of many techniques that my working-alone mindset comes up with after having read early on John Carroll's book, Working Alone. I recommend it for any serious DIYer. The triangular braces in the nearby photo that are clamped to the mudsill while I was using it as a straight edge to assess the levelness of the concrete wall (previous post) was suggested by Carroll. The four that I made exactly to his prescription have been enormously helpful in many ways. (Ever tried planing a door while holding it between your legs? Try using Carroll's braces.)
I needed two other measurements for the trusses. One was the difference in height between the front and back walls, the value of which gives the roof pitch. This task was made easy by the rotary laser. The other measurement was the horizontal distance between the walls which I obtained in one area only. Since the situation is a right triangle, the difference in height and the distance along the slope would be sufficient to calculate the horizontal distance between the walls . But as a DIYer, I was more comfortable pulling all three measurements. And for added comfort, I asked my mathematician brother-in-law to make the calculation and found that his calculation coincided with the measured distance.
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