Dead Loads

Dead Loads are referred to gravity loads of constant magnitudes and fixed positions that act permanently during the lifespan of the structure. it includes the weights of the structural members itself and that the material and equipment permanently attached to the building. To remain accurate, the weights of permanent equipment, such as air-conditioning systems, should be applied based on manufacturer information. The  table gives an estimation of different dead loads magnitude:

Dead Load Adjustments:

As you know dead loads are distributed on the floor. To simplify the analysis the standards suggest to transfer their effect to their utility lines. However this simplification might pose a degree of inaccuracy, to be on the safe side structural engineer usually  increase the dead loads by 10 to 15 lbs/ft²(psf). Moreover if there is a masonry wall in the building, designers usually try to position a beam directly under the masonry wall to ensure the its weight is going to be supported by columns. If positioning a beam under masonry wall is not possible, it is highly recommended to consider it as an additional floor with load pressure of 10 to 40 lbs/ft², depending on the masonry wall size.