Building My House

I have always wanted to build my own house. I am retired now, so I have the time. I found some land, designed a house that would fit the land and my needs and got started. I am doing all the work myself, so progress will be fairly slow. To read this blog from the beginning, start with the oldest archive and read posts from last to first.

Thursday, November 20, 2008

53: The Trusses Are Up

Originally I planned to build my own trusses, but then I called a truss company and they quoted me a per truss cost of about $56 and a delivery time of less than a week. So, all of a sudden ordering trusses made a whole lot of sense. I could get the house in the dry a lot quicker if I didn’t have to build trusses first.

The truss company sent out a rep to measure and to discuss options. At my site getting a crane in to set the trusses is impossible, so they absolutely had to be hand raised. The rep said my 30’ trusses (with 16” tails) would run about 130 lbs apiece, not to hard for three people to carry. So, it looked like I was going to order 31 trusses, one gable truss and 30 trusses known as a T64 design.

My workshop has 22’ trusses set on 4’ centers. So, just on a whim I asked the rep what would change if I wanted to set my house trusses on 4’ centers. He said it wouldn’t be any problem, they would just have to beef up the trusses a little, specifically changing the bottom chord from a 2x4 to a 2x6. Oh, and the truss weight would go up about 30 lbs to 160 each. Also I would have to put in 2x4 furring strips on the bottom chord because sheetrock for the ceiling can’t span a 4’ distance. None of those things bothered me. The idea of hand setting 16 trusses that weigh a little more is much more appealing than setting 31 trusses that weigh a little less.

One week later my trusses arrived; total bill $1174 (shipping was free). The next day some guys I eat breakfast with found out they had arrived and offered to come over immediately and help set some trusses. I couldn’t turn that offer down. The gable end truss was on top of the stack so we set that one first. It weighed 180 lbs.

Now, let’s talk a little about method. I knew I couldn’t use a crane; too many trees in the way, and too narrow a lot to get the crane down either side. I had done a lot of research and thought on how to hand-set these trusses safely. Remember, safety was my profession, so usual methods used by some builders might not be acceptable to me. I definitely didn’t want to have a man standing (or sitting) up on top of the exterior wall pulling up trusses. It’s 9.5’ down to the subfloor on the inside and anywhere from 13’ to 18’ to the ground outside of the wall. The last thing I wanted is for someone to fall off the top of that wall. Working off a ladder would be acceptable, but NO one goes up on top of the wall. Believe it or not, I actually did check prices of fall protection harnesses with shock absorbing lanyards. The cheapest one was almost $200. I found a hunter’s fall harness at WalMart for $75, but it looked like it wouldn’t work very well. So, we had to find a way of getting the trusses up on the walls while working preferably from floor level.

Okay, next point. Busting your gut man-handling trusses like this is a one way ticket to a back injury; so mechanical assistance is a must. I still had the block and tackle that I used to raise and sheath the exterior walls. But, even better, one of my friends loaned me a really nice block and tackle with 4 wheels and half inch nylon line. Now that rig was nice. I erected a 4x4 column (12’ tall) and braced it to both the outside wall and to the floor. It looked like we were ready for business.

We carried each truss in and layed them down diagonally across the subfloor. The trusses are a total of 34 feet long, so in a 29’ wide building they have to go diagonal. All three of us would get on one end and lift and rotate up until the truss was vertical with the opposite top chord still flat on the floor. This put the truss heel on our side about 10’ above the floor; perfect height to slide the truss over onto the wall top plate (9.5’ tall). That was a stroke of pure luck, not having to lift the first side up on the wall.

All three guys move down to the other end of the truss and pick it up and walk forward about 10 feet until the truss end is next to the lifting column. As you walk forward the opposite end will slide further up on the top plate. Hook up the block and tackle and up she goes. As you clear the top plate and start lowering again, the other two guys slide the truss forward 6-8 inches so it sits on the top plate too. Yes, the truss is now upside down, but hanging from the tops of the walls. Slide both truss ends along the top plate to the desired position and then rotate it up.

I knew we would have to put a temporary brace up near the peak of each truss and that is 15 feet above the subfloor. I checked out 12’ A-frame ladder prices and they were outrageous (cheapest one I found was $180) so I built myself an A-frame ladder out of four 12’ long 2x4 (total cost $12 plus tax). It’s heavy, but it is stout. I have no problem standing with my feet at the 10’ level and feeling secure while I attach the peak brace. We put a c-clamp on the upper brace 46.5” from the previous truss so that when we rotate the next truss up it would give us something to catch the current truss and keep it from rotating over the top. Once the truss was up and in position, we would nail off the temporary braces, a total of three braces on the top chords and two braces on bottom chords. We had 30-45 mph winds forecast for the first night and I didn’t want any trusses coming back down.

Everything went pretty smooth until the last truss. We were rotating it up and the long push stick slipped off the truss. I was on the short push stick and as the truss swung back down it caught my push stick in the webs and then hit me in the ribs with that same push stick. All it did was knock the wind out of me for a minute, but I was lucky; it missed hitting my head by about a foot. In retrospect now, I’m reminded of a very common accident cause from the many accident investigations I did when working. It’s called over-confidence and getting complacent. We had put 15 other trusses up without a hitch and on the last one our complacency almost got someone (me) hurt. Another cause I have identified was that the truss rotated out of the long push stick because wooden “vee” that we had on the end of the long push stick needed to be bigger. Our vee had maybe 5” sides and it probably needed 7” sides. The last pic is the wooden vee that was too small. I include it because I truly don’t want to see anyone get hurt.
It took three days in all to erect and temporarily brace all the trusses. I’m now attaching all my permanent bracing and starting to put on the 2x4 purlins that the metal roof will screw down too. With any luck I’m in the dry by Christmas.


At 7:59 AM, Blogger Ed Abbey said...

I've put up enough trusses in my life to have been wondering how you were going to do this by yourself. Glad to see you had a couple helpers. The fewest I've done it with is two. We would do the bust a gut for the first couple and then generally rig a block and tackle to a contraption that slides on the peak of the previous set trusses to hoist the remainder of the trusses in place but that requires someone up top to fasten the hoist to the previous trusses and to nail the set trusses off. I always just used one inch webbing to fashion a harness with as short a leash as possible. It doesn't have any absorption like expensive models but it would still keep you from slamming the ground. Might have a wedgie and some sore ribs the next day. The best way in the end is to have several friends, one of which is safety conscious. Hope you get your roof on before Christmas.


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