My first solution to this problem of installing a garage door is to find a
garage door type that can be attached to the inside edge of the jambs and not
within the jamb opening itself without having to cut off 4.5" of the bottom
of the existing header. "Like a roll up sectional door."
If they don't like this suggestion then:
The question that comes to my mind is what magnitude of load the beam in
question is supporting. I would have to assume that a GLB was used because
it was required for the loading.
As a matter of comparison, cutting the beam span down from 16' to 8' reduces
the bending stress by 4 times;. the shear by 2 times. If needed I would add
a 2x on edge or a parallam on the inside face of the reduced depth GLB and
attached it with lag bolts.
My other question is what is the allowable stress of the inside remaining
laminations when 4.5" of the bottom is removed? If the beam is all DF how bad
can it be comparatively? Note that they propose to cut the beam span in
half. And that the GLB will be reinforced.
My thoughts for this particular situation, only.
Shafat Qazi wrote:
> One of my clients wishes to install a garage door to his two car garage.
> The header beam is too low and needs to be reduced in depth by about 4.5
> inches. One of the solutions proposed by the client's contractor is to
> remove the bottom three laminations and add a new post + pad about
> mid-span. The current Glulam beam is 21 inches deep. It works as a 16.5
> inch beam for the reduced span.
> Question: Is there a problem if he cuts 4.5 inches from the bottom of the