Roof Ridge Shear Transfer

This can easily be accomplished in a number of ways but it is often overlooked at the job site.

Roof ridge shear transfer.

Designing a metal building for wind and seismic forces includes calculating the shear forces a cting on the walls and designing a method for the transference of those forces to the vertical frame. The roof of a structure contains a component called a roof diaphragm that acts as the transfer vehicle for the forces of the wind and seismic movement against the outer walls. Continuous ridge board or ridge beam and solid sawn rafters angle clip. Our brackets provide allowable in plane shear resistance capacities of 1750 2475 lbs.

The shear transfer capacity of this kind of blocking is less than that of full height blocking but it provides room for insulation ducts etc. In wood framed construction it is important to transfer lateral forces from the roof framing to the shear walls below. In steeper roofs the ridge might actually begin to act like a chord member and help in resisting the bending forces. From what i ve seen there is a lack of testing on pitched diaphragms in general for both plywood and steel deck.

Depending on bracket size framing method and roof pitch. The brackets take the place of the connection between the roof sheathing and the continuous ridge board or ridge beam in blocked diaphragm applications. Shear x brackets are designed to transfer in plane shear forces in roof diaphragms across the ridge. Blocking along the perimeter of the roof diaphragm that has the ability to transfer loads into the side walls or shear walls.

At a ridge you re transferring that same shear across a joint between framing members that likely has questionable weak axis moment shear transfer capacity truss plate. The rafter force is transferred through an angle clip to the ridge board or beam and again transferred through an angle clip to the rafter. Roof diaphragm to the shear walls. In addition this connection can be hard to observe once exterior sheathing or house wrap is in place.

Shear x brackets are designed to transfer in plane shear forces at the ridge line of roof diaphragms why use shear x. The brackets allow the use of continuous ridge venting in blocked diaphragms by replacing the boundary nailing between the roof sheathing and the ridge board ridge beam that is lost due to the gap required for venting. The ridge element acts to transfer the shear loads from the sheathing on one side of the roof to the other. The swenson shear stone coat cutter is designed for use on a multitude of metal roof applications from stone coated metal shake and shingles to 14 gauge stainless flat sheets.

Whichever the case applications of a ridge vent in these types of highly loaded roof systems would require special framing. The block is installed between roof truss heels at the top of the exterior wall to carry and transfer lateral forces from the roof diaphragm to the braced wall.