(2) 2x12 Beam
(2) 2x12 Beam
(OP)
I'm checking a case where someone knocked down an interior wall and spanned 20' in his one story home with a (2) 2x12 beam. The only loads are the ceiling joists that are connected to the (2) 2x12 on each side with hangers, they're not resting on the beam. There are no equipment in the attic. He also doubled up a 2x4 under each support.
The (2) 2x12 is on the interior of the home with one side resting on the exterior wall and the other side resting on an interior wall.
Question: Is it safe to assume only a dead load from the ceiling joists of 10 psf in this case to check deflection and stress? I don't see any other place where loads are coming from.
Sincerely...
The (2) 2x12 is on the interior of the home with one side resting on the exterior wall and the other side resting on an interior wall.
Question: Is it safe to assume only a dead load from the ceiling joists of 10 psf in this case to check deflection and stress? I don't see any other place where loads are coming from.
Sincerely...





RE: (2) 2x12 Beam
Residentail
10 psf live load if uninhabitable attic without storage
20 psf live load if uninhabitable attic with storage
habitable attics would be more loading
The 10 psf DL from ceiling only sounds reasonable you just need to add the appropriate live load too.
RE: (2) 2x12 Beam
This might add quite a bit of load. If this wasn't done - look at the ridge of the roof - I'll bet its sagging in the middle.
Also - how old is the building??
RE: (2) 2x12 Beam
Originaly, there was a (2)2x12 beam spanning 10'. the homeowner took out another wall to make the span now 20'. He replaced the 10' (2)2x12 beam with a new (2)2x12 beam spanning 20'. However, homeowner told me that he removed a 2x4 that was attached to the 10' span beam and to a 2x4 that was connected to 2 rafters to make room (crawl space) in the attic. But didn't replace the 2x4 bc he didn't think it was doing anything.
thanks
RE: (2) 2x12 Beam
Check that the posts (columns) have squash blocks carrying the load to below. You could also be overloading a basement I-beam or wood beam.
Of course my favorite question to the home owner is - Why ask me now that you have already done it??
Easier to ask forgiveness than ask for permission??
RE: (2) 2x12 Beam
Also, generally, without knowing the lumber grade and material properties of the wood on specific jobs, can you assume a conservative value for allowable yeild stress? - I always like to be on the conservative side anyway.
thanks for ya'lls help,
RE: (2) 2x12 Beam
RE: (2) 2x12 Beam
Squash blocks go between the floor plywood to the beam or column below. Too often, an inexperienced builder will set the first floor column right on the existing floor. If that happens in the middle of two floor joists - only the plywood ends up supporting the column - NOT good.
RE: (2) 2x12 Beam
RE: (2) 2x12 Beam