The only way to determine if a given wall is load bearing is by a hands on investigation to determine what load, if any, the wall is supporting. You cannot do the work over the internet, and photos only go so far. You need to open up the space above the wall to see what the wall is holding up.
These condos are stacked like boxes so directly above this wall another same wall is built as an exterior wall with a covered patio above my sunroom. Also, I took another look at what is above that upstairs unit and I didn't line things up right on site - the area above the upstairs unit is a flat rooftop deck with waterproofing with wrapped metal sheeting and 1/8" epoxy sprayed/rolled layer - no trussed roof or any other weight. Although people can go up there like a patio, so live load too.
So this 4x12 dimensional beam is taking the weight of the upstairs wall directly above it, half the dead and live weight of the upstairs 9ft wide covered patio, half the dead and live weight of the 12ft wide upstairs living area, and half the weight of a 21' width of rooftop deck.
Assuming this beam shares all weight above, I calculated the tributary or contributing loads, with a deflection limit of L/360, as:
- the upper level wall dead load is 128 pounds per lineal foot
- the 2nd floor living area live load is 30psf X 6ft= 180 pounds per lineal foot
- the 2nd floor living area dead load is 10psf x 6ft = 60 pounds per lineal foot
- the 2nd floor covered patio live load is 30psf x 4.5ft = 135 pounds per lineal foot
- the 2nd floor covered patio dead load is 10psf x 4.5ft = 45 pounds per lineal foot
- the 10.5ft portion of the waterproofed flat roof deck live load is 30psf x 10.5ft = 315 pounds per lineal foot, totaling
- the 10.5ft portion of the waterproofed flat roof deck dead load is 15psf x 10.5ft = 158 pounds per lineal foot
- total load is 1,021 pounds per lineal foot
I just can’t find a table that states the load capacity of a solid sawn 4x12 dimensional beam to know if it can handle the 1,021 plf. Anyone have a link to a table for a solid sawn 4x12 dimensional beam? I didn’t find it in the International Building Code or Residential Code. Thanks.