How to build floating shelf benchwork for a model railroad

At the local hardware store I noticed various floating shelf designs. Because there are no visible brackets, this shelf support system is sleek and uncluttered.

For a wider shelf to work, the backing plate against the wall had to be harder than the soft pine typically used for layout benchwork. The soft wood could work free from the mounting bolts. I also needed to minimize the shelf’s weight, while making it rigid enough to resist warping.

After some experimenting, I found a combination of materials that’s lightweight, stable, and visually clean. My floating shelf benchwork consists of a poplar backing plate, select pine outriggers, an extruded-foam benchwork top, and wood lattice fascia. Follow along as I describe how to build this sturdy and professional-looking shelf layout benchwork.

1⁄4″ x 11⁄4″ washers
1⁄4″ x 21⁄2″ lattice
1⁄4″ x 3″ lag bolts
1 x 3 pine
1 x 3 poplar
1″ panel board nails
2″ extruded-foam insulation board
3″ drywall screws
Foam-safe adhesive caulk

Lance made the outriggers from select pine 1 x 3s, cut to 16″ lengths to match the width needed for his layout. He used a Forstner bit to drill 11⁄2″ holes in the end of each outrigger to reduce its weight. Lance hasn’t tested lengths longer than 16″. Keep in mind that the added weight of wider shelves may make this design unstable.

Lance located the studs behind the wall in his train room. These studs are on 16″ centers. After drilling pilot holes, he then drove a 1⁄4″ x 3″ lag bolt through the poplar backing plate into each stud. He made sure the plate was level before driving the bolts. Before mounting the plate, Lance attached the outriggers with 3″ drywall screws as shown in the illustration. Wood screws would also work well to attach the outriggers to the backing plate.

It’s important to use a harder wood, such as poplar or maple, for the backing plate. This makes it less likely that the lag bolts will loosen and cause the shelf to pull away from the wall. Lance located the bolts near the top of the plate to further resist the downward pull of the finished shelf’s weight. The large 1 1⁄4″ washers keep the bolts from digging into the backing plate by spreading out the lag bolt’s load.

Lance checked to make sure each outrigger was level. To fix an outrigger that isn’t level, loosen the adjacent lag bolt, then drive a wedge between the wall and backing plate and retighten the bolt. If the outrigger is ascending, place the wedge at the top of the plate. If the outrigger is sagging, place the wedge at the bottom.

For the benchwork top, Lance cut 2″ thick extruded-foam insulation board to fit between the outriggers. He cut the foam so friction alone would hold it in place. After test-fitting the foam, he removed it and applied a bead of DAP adhesive caulk on the inside surfaces of the outriggers and backing plate. He then pressed the foam in place, making sure it was flush with the top edges of the base plate and outriggers. The photo on the right shows the foam in place.

To give the benchwork a finished appearance and add some extra rigidity, Lance searched for a fascia material that was both strong and lightweight. He found his solution with 1⁄4″ x 2 1⁄2″ wood lattice molding. Found in most home centers, lattice is usually available in 8-foot lengths. He attached the lattice to the 1 x 3s with 1″ panel nails. It’s a good idea to drill pilot holes in the lattice to avoid splitting the thin wood.