Construction Question

[Falthead]

I live in a ranch house with a single car attached garage I want to expand it to a two car garage. I would like to have a single garage door. My questions concern the support over the door and the support when I remove the side wall of the garage. The current ceiling joists run perpendicular to the garage door opening. A builder recommended to put up a 12" x 24" steel beam over the door and where the current end wall will be removed. Does that seem a little over kill?
The second question is about the side wall removal. the current concrete floor has lost its surface and is powdery and the surface is all rocks. I would like to pour a new slab for both bays of the garage. How would I support roof if I remove the end wall for the pour?
Sorry for the lengthy questions -thanks for any help!

 

[Franz©]

Sounds like the "builder" has a beam he either wants to sell or rent for a hefty price. Then again if the roof will have a 12 foot snowload he might be onto somethng.

You support the roof during the pour by extending the beam beyond the walls and putting cribbing or posts under it till the pour cures. Then you transferr the weight back to the foundation.

 

[kbs2244]

I like steel beams over big doors but 12 inchs for a 16 foot door is too much.
As long as there is no second story to support, a 6 inch beam will work fine.

If it is an attached garage, you have a perimiter foundation with a slab poured inside it. They pour the new "U" shaped rim befor anything else.
Then most guys will remove the triangle gabel end of the side wall. and just move the old wall to the new location. Then build the back wall to fill in the empty space. The front wall comes last. With the old door removed and cribbing for support, the old front wall comes out and the new header and wall above it goes in.
To avoid a "bump" in the roof where the seam between old and new is, make sure they remove the 4 x 4 pices of plywood roof seathing at the old edge of the roof and bridge over onto the new roof joists with 4 x 8 pices. They can reuse the 4 x 4's at the new edge.

 

[Falthead]

Thank you for all the useful information.