Builders frequently use laminated veneer lumber (LVL) to span the distance between a building's outside walls and to serve as floor joists. LVL beams are stronger and stiffer than normal lumber because LVLs are engineered so that strength-reducing characteristics, such as knots, slope and grain, are minimized during the manufacturing process. They are available in various lengths, so finding one that meets your needs should not be a problem. Although they are a manufactured product, cutting an LVL is no different from cutting a regular piece of lumber.
Measure from the end of the beam to the place you want to make your cut and mark it with the carpenter's pencil. Lay the carpenter's square across the beam at the mark and draw a cut line across the beam.
Lay the beam across the sawhorses so that the cut line is just past one of the sawhorses.
Grasp the circular saw with one hand while holding the shorter end of the beam with the other. Squeeze the trigger on the saw and ease the spinning blade against the cut line.
Move the saw along the cut line until you have cut completely through the beam.