Timber Beam Capacity
Timber Beam Capacity
(OP)
Dear All,
I'm conducting a structural assessment of an existing building. The roof structure consists of double 2x6 rafters at 2 foot centers. Once of the rafters is a full length while the other has a joint at different locations but on either side of the joint there are two bolts 6 inches away. The two members are nailed together along the rest of the length with 2 nails every 6 inches. I'm looking for some help in analysing the moment capacity of a beam like this.
I was thinking of analysing it such that each member had a tributary width of 1 foot. I would then consider that the full length member supported the spliced member and as such would induce a point load at the location of the joint.
Any thoughts?
I'm conducting a structural assessment of an existing building. The roof structure consists of double 2x6 rafters at 2 foot centers. Once of the rafters is a full length while the other has a joint at different locations but on either side of the joint there are two bolts 6 inches away. The two members are nailed together along the rest of the length with 2 nails every 6 inches. I'm looking for some help in analysing the moment capacity of a beam like this.
I was thinking of analysing it such that each member had a tributary width of 1 foot. I would then consider that the full length member supported the spliced member and as such would induce a point load at the location of the joint.
Any thoughts?






RE: Timber Beam Capacity
Why not analyze 2 ply 2x6 built up beam based on a tributary width of 24"? Then look at localized moment and shear at the splice locations. At each splice location, you only have the shear and moment resistance of 1 ply. Following that, interply connections (bolts/nails) would have to be looked at.
RE: Timber Beam Capacity
I would bet if you did your original train of thought that the single 2x6 picking up the point load from the spliced member would fail miserably.
RE: Timber Beam Capacity
BA
RE: Timber Beam Capacity
Mike McCann, PE, SE (WA)