Oxmore Benchwork

Posted on August 14th, 2016, by Michael Rountree

During the summer of 2016, I have been working on the next segment of benchwork. Oxmore sits on a tricky piece of real estate, fitting onto a wedge that goes from the drop-leaf bridge at the wide end down to a point near a basement support column, and then it must fit between the column and the stair. Stability is a big concern, though the drop-leaf bridge is built as its own freestanding element, and the adjacent benchwork just mates up to it.

A helix tucked into the corner beside the stair will allow access to an upper level above Trellisville; the mainline will flow down one turn while the Archibald Creek branch line will rise up 4 turns. This creates yet another critical alignment, and so I figured I need to at least get the base of this started. So this stretch of benchwork essentially connects a drop leaf to a helix, bypassing a steel column along the way, all while keeping the walking path up and down the stair free and clear.

The first part was to establish a level platform to build up from, which is 2×3 framing with 3/4″ plywood on top, with little blocking to set it to level above the uneven basement slab. Above this roughly 4″ plinth, I build a bottom shelf piece that is composed of tempered hardboard and clear pine 1×2 or 1×4 lumber. Each shelf is essentially a tray with 1x2s (or 1x4s at the bottom) wrapping around the bottom. Then, to the outside of this I affix panels that are made of 1x6s with 1x2s wrapping them, screwed in from behind where possible, though with the wedge shape it wasn’t always feasible to do so. Finally, I insert some hardboard panels in choice locations in order to serve as shear diaphragms that keep the whole box shape from racking.

After getting this base built, the upper portion will be separate and just sit on top, and be firmly anchored to the drop leaf, column, and helix, which meant that it was time to establish the helix. The paneling came off the studs and the wall framing was modified to allow the helix to overlap it slightly, and the whole helix framing is built out from the wall studs. This portion won’t have the same base shelving system, as access to the interior of the helix must be maintained.

The plywood deck here is just a base level, the actual helix will be lofted on threaded rods above this. This plywood serves as another shear diaphragm to make the whole structure surprisingly rigid. The board in front of the column extends out to where it will meet the upper level benchwork of the Oxmore wedge.

The yellow level is sitting right where the silica sand mine will be, on a shelf only about 6 inches wide, and behind that will be the barrel backdrop that hides the helix. This will be seen and operated from the stair itself, though there won’t be any backdrop between the column and the helix so it will also be visible from the aisle side.

The upper level benchwork is adapted from the pattern I’ve used elsewhere, with tapered piers on 16″ centers and more shear diaphragms where needed, to make an intact “box”. The very top will be 1×2 joists that sit atop the 1×3 L-girders. Each L-girder follows the outside line of the wedge with their legs turned inward, because I want to create a hard mounting point for a backdrop. I actually hope to make the backdrop removable, so that it can be placed on either side of the wedge, for viewing either way.

Leave a Comment