Roof Truss Design

• A roof truss is designed to withstand the weight and stress of your home's roof. That is why it is built in a triangular shape. Common trusses have a main horizontal beam called a bottom chord, and two beams set at an angle — called the top chords — with several support beams called braces in between the two. A typical common truss configuration includes three perpendicular braces and two angled braces, or four angled braces, each spaced to provide the greatest possible support and strength. Many other truss designs may come in handy when building an addition or remodeling a home.
  
  

Scissors Truss

• The scissors truss has two angled bottom chords, along with two angled top chords. As you may imagine, this truss is used to build a room with cathedral ceilings. If you plan to remodel a home and install a cathedral ceiling, this is the type of truss to use. In addition, if you are remodeling a cathedral ceiling, you'll deal with a scissors truss if you are running wiring or plumbing, or replacing drywall on the ceiling.
  
  

King and Queen Post

• The king post truss is the most simple in terms of parts because it includes two top chords, a bottom chord and one central vertical support post. As with all other trusses, these parts fasten together with a gusset, or a brace made of plywood or metal. When adding a new garage or shed, or renovating smaller rooms, you might encounter this type of truss. The queen post truss is the same as a king post truss, except it has two more angled support braces on either side of the vertical post. Designed for larger roofs up to 22 feet, it is also used in garages and in home additions.
  
  

Fink and Howe Trusses

• A fink truss uses only angled support braces between the chords, while a howe truss makes use of both angled support braces, and braces perpendicular to the bottom chord. These trusses are designed for larger roofs and are ideal if you are adding another story to your home, or replacing the entire roof. A triple fink and triple howe both accommodate roofs up to 80 feet wide. These trusses are for common roofs only. If you plan on installing a room in your attic over a new garage or addition, a room-in-attic truss with framing for a room built into the design is what you'll need.