Often times you learn truss raising the hard way. Fingers between trusses, backs strained from the heavy lifting and long strung out days. You live and you learn to just call a crane company for a day when you are installing large trusses.
Before the roofing materials and trusses are dropped at the job site, we encourage you to think about where the crane will be positioned to easily have access to the materials and so the space is cleared. Before the trusses are lifted to the roof, the crane should hoist the sheathing, shingles and any interior building materials to the second floor. You should not have to move the crane to reach all areas of the house. Make sure you keep your scrap pile way behind the other side of the house so it is way out of the way on raising day.
When the trusses arrive, we land them on top of blocks as they come off the truck to keep them as flat as possible and out of the dirt. Sometimes trusses arrive a few days early and a warped truss is much harder to install than a flat one.
Laying out your Trusses
It is important to mark your trusses while they are on the ground. You should mark three different sets of lines. The first set is for positioning, the second is for drywall screw lines and the third is for the roof sheathing. You can also mark the front of the trusses near the tail of the top chord to avoid getting them spun in reverse when they’re lifted. Before you mark these lines, the trusses should be aligned on top of one another as close as possible. Once they are stacked, it is much easier to create your lines.
Complete your Gable Trusses before Raising
Another way to save time is sheathing, siding and trimming the gable-end trusses before raising with the crane. This saves time and energy working up high and requires just a little planning. To help setting the gable truss, nails are started along the bottom chord. When the truss is in position, a crew member will drive the nails into the top plate of the gable end wall.
When you let a crane do the heavy lifting, you can lift the first three or four trusses at once. When you have a few trusses on the top, you do not have to have major braces set for the first truss. You can have the crane hold the place and weight of the first truss and nail in place.
It is also important to give your crew specific jobs while lifting your trusses. Make sure all tools are laid out and in reach so you can save as much time as you can while you have the crane on location. We need a guy to be in charge of signaling the crane driver, two guys on the ground to help strap and launch loads, two guys inside the house to un-strap the loads. Once the trusses are all launched you can reposition your two guys on the ground inside the house to secure the trusses in position.