How far can scissor trusses span?
A scissor truss with 6/12 top chords and 4/12 bottom chords can only span 22′. If you add larger lumber, like 2x6s, then you can increase the span by roughly 9′.
Are trusses made with 2×4 or 2×6?
Trusses only use 2×4 lumber and are constructed using a “web” of 2x4s for strength. Rafters simply rely on a center ridge beam and the outside walls for support. While there are benefits to both, only rafters vary in the size of lumber that is used.
How is truss span measured?
The span of a truss refers to the length of the bottom chord covering the width of the room or structure that the truss is covering. The span should not be confused with the overall width of the truss, which includes the overhangs.
What are scissor trusses used for?
Scissors trusses are used almost entirely in building construction to support a pitched roof, where a sloping or raised ceiling surface is desired.
How far can you span a 2×4 truss?
A 2×4 can span a maximum of 6′ 7” when spaced 16” apart and used as a floor or deck joist. When used as a ceiling joist or a roof rafter, a 2×4 can span up to 7′ 3” spaced at 16”, and 6′ 4” when spaced 24” apart.
What is a scissor roof truss?
A scissors truss is a kind of truss used primarily in buildings, in which the bottom chord members cross each other, connecting to the angled top chords at a point intermediate on the top chords’ length, creating an appearance similar to an opened pair of scissors.
Do scissor trusses cost more?
Scissors trusses are going to be more expensive than standard trusses of the same span, slope and load carrying capacity. As a general rule of thumb, the scissor truss will be 15 to 30% more expensive than a standard truss.
How much weight can a scissor truss hold?
According to the IRC, the minimum live load capacity of a roof truss for non-sleeping areas should be around 40 pounds per square foot. Again, if it’s built for sleeping areas, it should be around 30 pounds per square foot.
How much weight can a 2×4 truss support?
The maximum weight capacity of a 2×4 stud is about 25,000 pounds to 30,000 pounds.