A Gable roof style is the most common and easiest roof to build. Two
flat sides with a pitch of 4 to 6. A steeper pitch (higher number) does
not collect as much snow but steeper pitches cost more. There is more
storage room in a steeper pitch and they are stronger having more
storage load capability. Some people like to match the pitch of the
roof on their house.
The hip roof is slightly more difficult to build than a gable roof, but is still a popular choice. It does not provide for ventilation as well as some other roof designs. However if your house has a hip roof you will probably want to stay with that design.
These two are the most popular but as you know, there are many other garage roof styles available.
Installing the Roof
Handle the trusses carefully, they are designed to resist to vertical
pressure only. Don't handle them on the flat or
leaned against the walls. Rather, they should be lifted onto the top of
the house with ropes or a crane if you have no help.
Precise support points on trusses ease their anchoring to the outside walls of the house. Before installing
them, mark anchor points every 24 in. (61 cm) on the double plates, then
begin installation at the gable end of the roof.
This image shows temporary sway bracing used to hold each truss into place. When the trusses are installed, nail the blocking into place, in accordance with the instructions supplied by the roof truss manufacturer.
Trusses provide the structure for the eaves, leaving only the facia to be installed. Close the roof in as soon as possible to avoid rain and wind damage to the roof and the rest of the house. Install plywood roof paneling perpendicular to the trusses and ensure the joints are always on a truss and are offset.