The Doug Fir beams for this project have had a long life before becoming a Timber Frame Staircase. The General Contractor for the project salvaged the wood from a previous project. They used to be support beams for a large pergola. He cleaned them up and dropped them off at my shop, where we went to work designing the staircase.
Traditional Japanese joinery methods for timber frame construction inspired the joinery. For each step, I cut a long tusk tenon on each end, fitted it through the stair stringers, and drove a wedge through the top of the tenon to hold the staircase together. The open back steps blends well with the modern handrail.
The final finish is a faux distressing stain to restore the rustic aged feel to the beams after fabrication..