Because the trusses are heavy and.
How to put up truss roof.
Install one bracket for each truss to the top plate on each wall.
Guiding the first truss into place.
Saw the truss members to size.
You need to use the level to make sure that each truss is perpendicular with the ground or 90 degrees.
You could start on one end and set them all square all the way to the other end and then deal with the two end trusses being out of square or as tom said start in the middle and deal with them on both ends.
Then they arranged them to get at the trusses that go on first.
As with rafter style roofs toenailing is one of the most common ways of attaching a truss style roof to a wall plate.
While most home builders will outsource the construction of roofing trusses the rafter supports of the roof itself learning to frame a roof yourself is one of the true arts of carpentry and a basic primer is covered below.
After designing the truss saw each member to its required length.
Toenail a truss into the top of the wall plate by nailing through the sides of the bottom chord at a 30 degree angle.
Nail in place to attach the trusses to the foundation of your shed and to keep them in place for the addition of your roof.
Roof trusses arrive at the jobsite on the bed of a large truck.
They need to be secure for permanent use.
Install a hurricane tie bracket in the joint between the top plate and the bottom board of the truss nailing through each hole in the bracket into the top plate and bottom horizontal of the truss.
Of course they were at the bottom of the stack.
Setting the first trusses.
Lay the truss members out on the ground.
They studied the plans to figure out what trusses go where.
As with any structural member a faulty design will undermine even the most professional of.
Attach the truss firmly to your shed.
How to set roof trusses diagram and layout.
Attaching the truss to the crane sorting the trusses into piles all over the yard.
Design your roof truss.
The only thing to do is pick where you want to have the out of square trusses once you get to the end of the roof.