2 and better (no loose or missing knotholes), then a 4×6 spanning 18′ will support about 105 lbs. Loaded at the mid-span (slightly higher if it’s loaded at third points or further from the center point).
How Much Weight Can a 4×6 Beam Support Horizontally?
A 4×6 beam is a structural component used in construction to support weight horizontally. The beam is designed to transfer loads from one point to another, typically from a wall to a roof or from a roof to a floor. It is important to know how much weight a 4×6 beam can support in order to ensure that it is used safely and that it can handle the loads it is designed to carry.
The amount of weight a 4×6 beam can support horizontally depends on a variety of factors, including the type of wood used, the length of the beam, and the spacing of the beam’s support points. Generally, a 4×6 beam of Douglas fir can support up to 3,000 pounds when used in a horizontal span of 8 feet or less with a single support point at its center. This weight capacity may be reduced if the beam has more than one support point, or if its length exceeds 8 feet.
When calculating the weight capacity of a 4×6 beam, it is important to consider the type of wood used. Softwood such as spruce, fir, or pine is much weaker than hardwoods such as oak, maple, or walnut. Therefore, a beam made of softwood may only be able to