The Most Terrifying Prospect
Working trusses single handed? No problem. How to put them up on top of the walls? Also no problem. When it comes to building a house with my two hands, nothing scares me.
My wife, however, is another matter entirely. Besides attempting to influence me toward getting some help in a general sense, one portion of the building project spooked her far more than any other.
Pam simply couldn’t see how in the world one man could take a thirty-six foot truss from a pile on the ground, lift it to the top of the walls, and secure it in place…without dying–or at least getting severely injured–in the process. She drove me bonkers, but being a stubborn old buzzard, I held my ground on this one. Not an easy task when you’re married to a worried redhead, let me tell you.
Fortunately, the day finally came to Get ‘R’ Done. My theory was that once my sweetheart saw a couple of trusses up and safely nailed in place, she’d relax.
At any rate, the walls were ready, and it was time. The first step was, obviously, to elevate the truss. Carefully finding a balance point that allowed me to keep everything but the far tip of an upside-down rafter off the ground, I dragged the long wooden beastie over to the nearest (north) wall. This dragging/carrying hold left the forward rafter tip high enough to clear the wall by just a bit. Once that tip was over the near edge and could rest there a moment, it was time to reposition.
Flat Across The House Walls
The key element to making one-man truss installation workable is the interior bearing wall. This runs through the center of the house on an east-west axis. By shoving and pushing and such, it’s practical to maneuver a truss to a point where it will gently come down balanced across the north and center walls before the “back end” gets too high off the ground to push effectively. This becomes the second resting position.
Stepladder Time And Lots Of It
Next move is to go inside the house, set the stepladder near the south tip of the truss (which is hanging out above the middle of the south half of the house), climb the ladder, and begin tugging/jerking the lazy lumber toward the south wall a few inches at a time. That eventually places the truss in its third resting position, i.e., lying flat across all three walls with the tips extending outside like the eaves they will become.
Setup And Securement
Now comes the clambering. If you’re not a natural born clamberer, oops, slapping up roof trusses without help is probably not a great idea. If you think words like “clambering” and “clamberer” sound absolutely ridiculous, join the club.
Still, clambering is the most descriptive word for what you’ll be doing. My procedure is to step from the stepladder to the wall top. After the first truss is in place, that requires going either over or through the truss (or trusses, as things proceed) as well. There are several things that have to happen in fairly rapid succession:
1. Get the truss standing up. With the first one, I was able to stand with one foot still on the ladder and apply plenty of leverage. From there on out, the method is to squat on top of the bearing wall, grip an already secured, vertical board on a nailed-in-place truss with the left hand and ditto for the unsecured truss with the right, and…pull. And…up she comes!
2. These rafters are spaced 24 inches apart. One end of a three foot chunk of 2″ x 4″ “tie board” has already been tacked to the secured truss and will be used to “make rigid” the one you just pulled upright, but not yet. First, gripping the “tie board” and the loose truss together in one hand (I’ve got big hands), I use a level to figure out where to nail the new guy on the block for it to be perfectly vertical.
3. When the correct position has been determined, it’s time to nail the “tie board” in place. With that done, the hard part is over. Relax, take a deep breath. Heck, you could even stop for a cup of coffee at this point. Bad idea, though, until you’ve done a bit more….
3a. For the first truss only, a long brace (a 20 footer in our home’s case) which reaches the ground outside the house is the first lumber to be nailed in place. Then a short piece (in the case of our 2″ x 12″ top wall) comes second, angled between truss and inner wall edge to lock things down for now.
It should be mentioned that the outside ends of the rafters need to be checked before all that clambering is done. You don’t want to discover after the fact that you’ve made a ragged row of rafters, eh?
Back to the stepladder. At either end of the truss, a single nail (I use 8d size) is toenailed to “lock” the truss firmly against the spacing block.
Oh, I forgot to mention that? Sorry…!
I discovered something just today that left me going, “Well, duh! Obviously!” The discovery had to do with the dimensions of a standard metal carpenter’s square. The longer, wider edge is two inches wide and 22 1/2 inches long. Why the half? See, it’s like this: If you get the Skilsaw going and quick-measure a bunch of board pieces exactly that long…and then you use those pieces to space between standard 2″ x 4″ trusses (which are actually 1 1/2 inches thick), you get a perfect series of rafters spaced 24 inches on center.
With the truss toenailed, hurricane ties are then nailed in place. They’re remarkable little metal designs, these hurricane ties. Five short but hefty nails with a lot of “grip” to them go into the truss. Five more go into the wall planking. That “lift resistance” (to keep your roof from blowing away in a hurricane) is then doubled… by adding a second tie. One goes on the outside of the wall and one on the inside. That’s for the exterior walls. Most commercial builders around here don’t even bother to use hurricane ties at all, but when you’re doing it by yourself and for yourself, it’s okay to do it right.
Very seldom would any builder bother adding hurricane ties to an interior wall. I’m doing it, though. Only on one side of the wall…and despite the fact that the nailheads will make the addition of wall sheathing a slightly trickier proposition. Interior walls are universally ignored because the wind uplift hits at the outside edges of the house, not in the middle of your living room–unless the homeowner is unusually long winded, anyway. I did settle for one tie per truss on that wall…which is good for close to 100 mph winds. If we get more than that inside the house, we’re done for, anyway.
Adjusting To The Interior Bearing Wall
In the process of building the interior bearing wall, my gravest concern was that the wall must not end up being too high. Balancing a truss on that center wall would not be a good idea. As a result of my caution, the wall top did end up a bit lower than it needed to be. That was okay, because I knew how to rectify the situation during truss installation.
My first plan was to use wedges. Fortunately, I got an inspiration–a much better idea, because wedges (used extensively to level mobile homes during setup) would have drastically interfered with the application of spacing blocks.
The brilliant idea? Simplicity itself: Cut a piece of 2″ x 4″ to length, stand it on end in the gap with glue to hold it in place long term, and call it good. Of course, “to length” is a relative term in this case, since the gap to be filled varies from a mere quarter inch to a bit more than an inch. But as long as the filler was on end, all would be well–lumber being much stronger in that position (think tree standing tall in forest).
And…Repeat The Process
The above procedure is simple and straightforward but does take a bit of time. So far, installation has averaged about an hour and a half per truss. The benefits to that slow pacing, however, include not having to listen to anyone else’s opinion, getting things done exactly as I want them done, and of course (especially important in the current economy) a total labor cost of exactly zero dollars out of pocket.
By the time today’s sun dropped over the horizon, five trusses and a bit of sheathing board had been firmly placed. Sheathing the trusses, however, will be the topic of the next article.
The Long Span
Update, Feb. 10, 2011. This bit of info (including the image below) is being added to the hub in order to answer a reader’s question regarding the length of lumber needed to build trusses designed to cross a 24-foot span.
First, the sketch:
In the sketch above, the truss is orange in color. Blue indicates exterior walls, and green is a bearing wall (optional).
There is only one board which runs across the entire span, i.e. the lowest board in the truss which seves as a base for the rest of the (truss) unit. It’s also the only board installed horizontally…and it must be a single unbroken piece from beginning to end. You just can’t afford to have the bottom of your truss splitting into two parts and dumping the entire roof on your head, doncha know.
Hope this helps.