Steel Beam Garage Door Header

I need to size a steel beam for over a garage door opening.

Steel beam garage door header.

We have an old cinder block garage shed building built in 1967 with 2 9 foot wide garage door openings. Doors in a load bearing wall that holds the weight of the house created by beams and trusses need a larger header than those in non load bearing walls. The beam they have specified now is 3 1 2 x 12 x 18 9. In an attempt to construct portal frames some garages are built with one continuous garage header extending over two or three garage door openings as shown in figure a.

The only added weight on the header will be 4 by 8 joists 3 4 plyw read more. The open span is 14 5 ft there will be a single point load of 4 200 lbs at 4 from one end. The beam must be strong enough so it doesn t break fb value and stiff enough so that it doesn t deflect excessively under the load e value. Portal frame details within the irc specify simple span headers with a maximum finished opening width of 18.

Add together all live loads and dead loads that act on the member and then choose a material that will resist the load. The idea behind sizing headers and beams is straight forward. On previous projects i have been supplied a glu lam boise makes specifically for garage door headers that was 3 1 2 x 11 1 4 x 18 9. The header for a door is much like a bridge transferring the weight above it to the floor and foundation below.

What size and guage of steel i beam do i need for a garage header. These 9 foot openings are only supported by a makeshift header consisting of 6 cinder blocks sitting horizontally across the top of the opening. I cannot exceed a beam height of 8. Opening is 18 ft wide and beam will rest on 2 18 by 18 posts.

Tbe row of 6 blocks have a 2 x 10 on top and a 2 x 10 below them.