Gable Roof Load Transfer

Roof framing typically consists of dimensional lumber rafters or engineered roof trusses.

Gable roof load transfer. These are the forces that apply pressure and must be considered in designing a gable roof. To transfer roof loads to the foundation ceiling joists are usually installed. When ceiling joists must be overlapped above a load bearing partition the overlap must be at least 3 the type of roof labeled a is a gable roof. The point at which all the rafters are attached to.

Transfers the load of the roof through the raftersto walls below. Framing a gable roof building a gable with barge end purlin struts and collar ties. Loads are transferred downward and outward through sloping rafters the lower ends of which rest on the top plates of the exterior walls. Ridge beam sits below the rafters.

That rafter outside forms the overhang for the barge boards to fix to and so the soffit boards and ventilation are continuous all the way. Loads affect the bracing roof covering. Three types of load apply to a gable roof. The picture above shows the plan view of a gable roof ladder trusses are made up using four noggins bridging at each corner to support a rafter outside the building.

For wide gable dormers where the walls will carry herculean loads lvls or steel i beams may need to be inserted into the floor system to hold up the roof. The roof and ceiling diaphragms transfer shear loads to the gable end frame which transfers these loads to the end wall below and into the foundation. The roof framing must also function as part of the roof diaphragm to transfer lateral loads to the shear walls below. And it s in these cases where i take extra care to follow the load path through the first floor and into the foundation with posts framed within bearing walls.

The roof decking and sheathing and resist loads applied to the sheathing and transfer loads vertically to support walls or frames. In order to do this the frame relies upon well designed connections to the bearing wall and diaphragms. Supported by lally columns. A gable roof is a roof that slopes downward from a central ridge to a building s exterior walls on two sides.

On the other two sides the roof terminates in a flat triangular gable. The type of roof labeled b is a hip roof. When erecting a gable roof which portion of. The exterior wall and the headers within will carry all loads from the mid point of the house between the supporting walls to the outside of the house including the roof overhang.

Although they don t bear the full weight load of the roof the gable end walls are also typically load bearing and an interior wall running parallel to the roof ridge in the center of the building often bears. Parts of a roof a ridge board is a horizontal member of the roof frame. So each lineal foot of wall must carry the loads imposed by a 1 foot wide strip in that 14 ft region. The vertical load on the roof is transferred to the walls.