[Randy Bush]

Normally a lot of framers do a 2x6 up the inside sides and top with the sides running up to the ceiling for track hardware, and blocking in the center for the opener. Outside brickmold or what ever you are going to trim the opening out with.

 

[Randy Bush]

We use 1x material for the door trim which I then wrap with steel coil.

 

[Randy Bush]

The 2x10 works with what ever siding they choose to go with it.
View attachment 718743

So does a 1x , , don't really care for the pictured look, especially with the Jam extending past the wide side trim. To boxy of a look.

 

[Randy Bush]

Guess different things for different areas , like most things. Things you do there in Canada , we never do here. Reason we have a difference opinion on a lot of things.