Kevin Jenness
10-08-2023, 10:43 PM
After decades of climbing a "temporary" stair I am building a finished staircase in our home. The stairwell is cramped due to the house designer's (me) inexperience, thus the complex layout which results in a 7 3/4" rise/ 8 7/8" run along the walking line, steep but workable. The stair turns 180 degrees with 11 treads plus a landing at the top, with closed housed and wedged stringers, all made of homegrown rift and quartered cherry from our woodlot.
I drew the stair in sketchup which allowed for accurate cnc routing of the stringers, a good thing since only two of the treads are common and all the other nosing intersections are ellipses, plus the tread overhangs would be difficult to make consistent using a conventional router jig. The upper stringers were scribed and routed into pockets in the second floor beams, one was joined to a lower stringer and the other to the lower newel post with 10mm dominos. The newels were bolted down with 5/8" all-thread potted in thickened epoxy, into the concrete slab at the bottom and into the wood floor and beam at the top.
The construction method allows for easy handling of the individual components and fitting on site to allow for any vagaries in the floors and walls. By removing the original upper landing I was able to move the temporary stringers enough to use them as a staging while fitting the stringers, far better than working off a ladder. Once the stringers were in the old stair went away, and although it took several days to fill in the treads and risers I was able to wedge all the treads in place temporarily so we always had easy access to the upstairs bedroom and bath.
The stringers and lower newel went into place according to plan, although scribing the newel to get a solid fit to the ceramic floor tile was fussy. The treads and risers had all been glued up oversize and had to be fitted individually. I used pinch rods and bevel squares to get the length and angles at each end of the treads, at which point the outside nosing ends had to be trimmed back with a rasp square to the housings, then the back edge of each tread was marked at the front of the riser housings. The saw cuts were all made on the sliding tablesaw fitted with a zero clearance table. The back edge of the treads had to meet exactly with the riser housings so that there would be no gaps when the risers went in. The parts were driven tight with 3 degree wedges set in polyurethane construction adhesive and the tread/riser connections were glued and screwed. It took me a week to install the stair up to this point, working alone except for a few lift assists from my wife.
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I drew the stair in sketchup which allowed for accurate cnc routing of the stringers, a good thing since only two of the treads are common and all the other nosing intersections are ellipses, plus the tread overhangs would be difficult to make consistent using a conventional router jig. The upper stringers were scribed and routed into pockets in the second floor beams, one was joined to a lower stringer and the other to the lower newel post with 10mm dominos. The newels were bolted down with 5/8" all-thread potted in thickened epoxy, into the concrete slab at the bottom and into the wood floor and beam at the top.
The construction method allows for easy handling of the individual components and fitting on site to allow for any vagaries in the floors and walls. By removing the original upper landing I was able to move the temporary stringers enough to use them as a staging while fitting the stringers, far better than working off a ladder. Once the stringers were in the old stair went away, and although it took several days to fill in the treads and risers I was able to wedge all the treads in place temporarily so we always had easy access to the upstairs bedroom and bath.
The stringers and lower newel went into place according to plan, although scribing the newel to get a solid fit to the ceramic floor tile was fussy. The treads and risers had all been glued up oversize and had to be fitted individually. I used pinch rods and bevel squares to get the length and angles at each end of the treads, at which point the outside nosing ends had to be trimmed back with a rasp square to the housings, then the back edge of each tread was marked at the front of the riser housings. The saw cuts were all made on the sliding tablesaw fitted with a zero clearance table. The back edge of the treads had to meet exactly with the riser housings so that there would be no gaps when the risers went in. The parts were driven tight with 3 degree wedges set in polyurethane construction adhesive and the tread/riser connections were glued and screwed. It took me a week to install the stair up to this point, working alone except for a few lift assists from my wife.
50874250874350874450874550874650874750874850874950 8750