The extra length for the header is to provide enough load bearing strength to cover the 16 foot opening span.
Standard 16 foot garage door headder size.
That would take care of the wind and seismic shear loads.
The span for the girder is based on the size of an average sized game room.
So for a 16 wide door your beam will have to be 16 6 long.
Only that the minimum net header size shall be 3 x ll 25.
Table 1 consolidates loading sizes and cost data for all of the applications.
If there isn t enough room above the opening this can t be done without raising the roof of the garage.
Window door garage door headers supporting roof loads only.
Window door garage door headers supporting roof wall floor loads.
That for a 16 foot wide garage door the header should be at minimum 9 inches longer than the door width meaning your header should be 16 feet 9 inches long.
If you are creating an opening no wider than 4 feet for a door or smaller window then you need a 2 by 6 header.
If you are having your trusses run at right angles to the doors usually the side of the garage you may bery likely need 3 lam beams on the 16 door and they may require you have 2 x 6 s for your jack studs.
If the opening will be 5 to 6 feet wide such as for double doors then you will need two 2 by 10 headers.
And the garage door header is based on a 2 car garage door opening.
Many 16 x 7 garage doors will be designed with a pair of single 8 foot garage door bays separated by a central post or column.
Header spans are typical for a window and a patio door.
Now here is a twist.
The standard size for double garage doors is 16 feet wide and 7 to 8 feet high.
Many home builders do not consider this a structural necessity but a style and price choice for the homeowner.
Tables providing size selections for various beam spans and loading combinations for southern pine dimension lumber and southern pine glued laminated timber are available for the following applications.
Width of garage door opening standard widths are 8 9 10 12 14 16 17 and 18 height of the garage door opening standard residential heights are 7 7 6 8 header the header is ideally a minimum 12 wide micro laminated beam that spans the width of the garage door opening.
The span above the door opening is framed with a long header that supports the wall area above the door and this header will need to be raised or rebuilt in order to increase the overall door size.
16 garage door headers mtlogcabin a minimum 3 x 11 25 net header size is required for opening from 6ft to a maximum 18 ft.
It also depends on which way your trusses run.