Using Trusses And Rafter Ties In Attic

Firstly the tributory width d should be 3d as only every third rafter is tied.

Using trusses and rafter ties in attic. The role of the horizontal beam is to tie the truss together and carry the load that would otherwise be sustained by the support and vertical timber also known as the king post. Determining which truss or rafter is the girder may require a trip into the attic. In most homes the ceiling joists also serve as the rafter ties. Rafters are a better choice for specialty projects.

Installation is the same for trusses as for rafters see above. Your home site is easily accessed. Since l is the half width of the roof the load should be w not w 2 and there are other serious things wrong with this. A lack of rafter ties is a serious structural issue in a conventionally framed roof.

In a nutshell trusses are right for most projects. Attic conversions are now possible by replacing the truss rafters with a shaped trusses or horizontal beams which in return create additional space. You don t prefer finished attic space. Also the un tied rafters push on the wall plates which span between the tied rafter ends bringing in 2 3 of the load on the tie and adding to the bending in the tied rafters.

Hurricane ties offer a strong connection that will provide you with the strongest resistance against uplift. Rafter ties are always required unless the roof has a structural self supporting ridge or is built using engineered trusses. Collar ties may take up space in the attic of your home but they are there for a reason. For hip roofs the code specifies that hip and girder rafters or trusses be connected to exterior wall plates.

In this how it works article managing editor debra judge silber explains the role of collar and rafter ties in the framing of a roof collar ties are necessary to prevent separation of the roof at the ridge due to wind uplift. The girder which by definition supports the inboard end of other framing members can be anywhere from 3 to 11 feet back from the corner. Scissor trusses will provide enough steepness for any vaulted ceilings in the plan consult your architect to determine that.