Using Trusses And Rafter Ties In Attic

Instead of attaching the tie to the rafter you will be attaching it to the bottom chord of the truss.

Using trusses and rafter ties in attic.

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 most homes the ceiling joists also serve as the rafter ties. Your home site is easily accessed.

For hip roofs the code specifies that hip and girder rafters or trusses be connected to exterior wall plates. You don t prefer finished attic space. Collar ties may take up space in the attic of your home but they are there for a reason. 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.

Firstly the tributory width d should be 3d as only every third rafter is tied. Determining which truss or rafter is the girder may require a trip into the attic. In a nutshell trusses are right for most projects. Rafter ties are always required unless the roof has a structural self supporting ridge or is built using engineered trusses.

Rafters are a better choice for specialty projects. Attic conversions are now possible by replacing the truss rafters with a shaped trusses or horizontal beams which in return create additional 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. Installation is the same for trusses as for rafters see above.

In homes with flat ceilings and an attic space the bottoms of opposing rafters should be fastened together with ceiling joists which form rafter ties when rafters have been installed perpendicular to the ceiling joists rafter ties typically rest on top of the ceiling joists. Best uses for trusses vs. 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.