The cost of lumber averages around $3.75 to $4.25 a foot. so if we take the middle of the road and figure the truss at $4 x 26 = $104 a truss. one thing to keep in mind right away is that four main things affect the common truss price: grade of lumber, amount of trusses, tax, and delivery. let’s take a look at this next truss for even more. A wood truss can be used for the structural framing of a building. wooden trusses are used to construct a large number of building components. they are frequently used to build floors and ceilings, and may even be used to frame exterior walls. wood trusses are also one of the most common materials used in roof framing systems..