Roofed Hinge Beam Construction Formula

Two 2 by 4 beams together would not be enough.

Roofed hinge beam construction formula.

In the example the beam spans the 10 foot width of the roof. F stands for the beam s fiber strength in bending which depends on the species of wood. The above formula may be used for finding out the reaction of a loaded beam about its end supports. The formula for the section modulus is beam width times beam depth squared divided by 6.

Beams are the long members of a structure that carry the loads brought by the horizontal slabs of the structures including floors and roofs. When beams carry loads that are too heavy for them they start to bend. Calculating shear force and bending moment the two important parameters also involved with beam load calculations are shear force sf and bending moment bm. The total load is 4 000 pounds.

Now the example formula is 4 000 1 000 bd 2 9 x 10. Beam deflection is the vertical displacement of a point along the centroid of a. Too often builders gang together 2 inch dimension lumber to support roof and floor loads without considering other options. The same is true for beams like structural ridge beams and center girders.

For the initial calculation f can be estimated at 1 000. A two 2 by 6 standard beam has actual dimensions of 1 5 by 5 5 inches which would give a section modulus of 1 5 x 5 5 x 5 5 6 7 6 which is not enough for this example. A 2 by 8 beam would be sufficient. We call the amount of beam bending beam deflection.