Building a Timber Frame Staircase

I built this timber frame staircase from reclaimed beams that came from another client’s house a few miles up the road. The beams were used to support a pergola that was torn down during their remodel.

We templated the area where the stairs were going to go and brought it back to the shop and premade them. The installation was fairly straightforward as they were already assembled in sections. All that was left was to put them in place and bolt them in.

The through tenons with the wedges were, of course, as much of my work. Inspired by traditional Japanese joinery techniques.

A recount of the video

The reclaimed beams have already been milled and sanded to thickness.  I started out by cutting them to length on the table saw.

Since the blade is at full height, for safety,  I use my knee to shut down the saw as soon as the cut is complete before moving the workpiece.

This material is just a little bit too thick for my saw to cut all the way through, so I use my Japanese pull saw to finish the cut.

And since the cut wasn’t perfectly flush, I used a pattern bit in my router to flush it up.

I am working with soft Douglas fir; it is prone to splintering, so I severed the grain with a knife to keep a clean shoulder.

Then, I cut the shoulder of the tenon to depth with my router.

Once I established the shoulder, I switched to a more aggressive bit and hogged off the rest of the material.  This method left a lot of tool marks on the tenon, which normally wouldn’t be a problem, but these tenons are going to be functional and decorative, so I came back with a hand plane and cleaned them up.

I set up the fence on the band saw to rip the tenons to width and used my Japanese pull saw to trim off the excess.  I used the same knife scoring technique to prevent tear-out.

To be sure the shoulders were seated tightly to the stringers, I took a few minutes to finesse the shoulder, cleaning up anything that wasn’t square to the face.

I laid out the rise and run of the stair treads marked out for the through mortises and headed over to the drill press to hog out most of the material with a Forstner bit.

I took my time to make a plywood template that fits perfectly over the tenons so I could use my router to quickly clean out the rest of the material.   I came back with a chisel to square up the corners and finish chopping through to the other side of the mortise since my router bit was not long enough to cut all the way through.

All those scrap pieces I cut off from the tenons I was able to rip down and use to create the wedges that would hold it all together.

To create the wedges, I set up a stop block on the band saw so I could quickly cut the decorative notch, and then came back with a wedge against the fence to cut a matching taper to complete the shape.

I did a little cleanup on the spindle sander to refine the shape and then built a plywood jig so I could quickly mark out the location for the wedges on all 15 steps.

To prevent tear, I used a chisel to stake out the perimeter of the mortise for the wedges, came back with a drill to remove the bulk of the material, and routed out the perimeter.

Once I established the mortise’s basic shape, I returned with a chisel and chopped out the rest of the material to match the taper of the wedge.

From here on out, it was a lot of finessing the fit.  Driving the treads in, testing the fit, driving the tread out, and relieving some material with chisels and hand planes.  So on and so forth until they all fit snugly.