When I started building urban decks, I saw them as a way to earn money to support my passion for woodworking. “This will be easy,” I thought. “I’ll just build a deck now and then, and with all the money I make I’ll take time to build furniture.” Then came payroll, taxes, worker’s comp, liability insurance, shop construction and rent, New York City parking tickets, bookkeeping, hours in my truck sitting in traffic, and long hours pushing miles of ipe over my saws. When I raised my head 15 years later, I had a 6,000-square-foot shop in Brooklyn, a half-dozen people helping me, and a wife and two children. I had also managed to build some furniture, support my family, and finish many roof decks and gardens. Along the way, I developed a straightforward and elegant system for building urban rooftop decks.

Urban Requirements
City clients who have outdoor space and are willing to spend top dollar to improve their homes expect that this improvement will happen rapidly and with minimal inconvenience to them and their routines. They do not want a lot of hammering noise disturbing them. Workdays on site can be short; building regulations often allow work only from nine to four. Some buildings have whole months designated as quiet, so that we have to wrap our hammers in velvet. The hurdles raised by building managers, engineers, co-op boards, and neighbors are multifaceted, with seemingly infinite combinations.

At least we are usually the only contractor working in the space. It’s refreshing to have control over the job site, without needing to work around other trades. Working on roofs, we are, however, at the mercy of the weather. This means that Mother Nature grants some days off — days off, that is, to work in the shop. Working many stories above city streets also dictates two hard and fast rules: Tie everything down so it doesn’t blow off, and place no objects above the height of the parapet — ever.

In New York City, almost everything has to go up by elevator, boom lift, crane, or scaffold lift. Of these, the elevator is our usual method of delivery. Sometimes we can’t use the elevator, though, and the only option is a staircase. Then tight switchbacks commonly make a puzzle out of the simple task of lifting and carrying. In some high-end buildings, I’ve seen staircase walls faux finished or lined with ostrich leather. One misstep can peck away at the profit with gusto, so we have to limit the length of the deck pieces, often to only 7 feet.

To address the constraints of the buildings I work in and to minimize the time spent on site, I designed an interlocking grid-and-panel decking system. It can be completely assembled and disassembled in the shop for assurance that the actual installation will go well (Figure 1),
and even after the deck is in place, it can be dismantled and reassembled to allow reroofing. It rests on the existing roof, without interfering with drainage, and it’s easily leveled. The panels can be delivered in stacks. We use ipe, stone, and a fiberglass honeycomb panel with recycled-rubber laminate as our surfaces, but many other materials could be used (Figure 2).

We build the grids from 5/4 ipe. Tough and weatherproof, ipe is the best choice for outdoors. The crosspieces of the grids are half-lapped. When the decking is also 5/4 ipe, I typically space the half-laps 2 feet apart, a distance 5/4 ipe spans well. The joinery of the grid is milled to a close tolerance, for fit and appearance. My crews preassemble as much as possible in the shop.

Ledger strips of ipe joined to the grid members support the panels (Figure 3). We adjust these strips to the appropriate height depending on the panel thickness, and we space them away from the grid members by about 1⁄2 inch to provide for drainage and to keep the end grain of the decking from sitting in water.

The decking panels are preassembled, with connections made on the underside of the boards so the screws aren’t visible (Figure 4, page 38). We cut them to exact size in the shop; all the fitting and connecting is done before we take the deck to the job site. We stamp numbers on the parts, load up, and away we go. This system works so well I’ve started selling the uninstalled components locally.

Working With Ipe
Building with ipe is a chore. Never mind that every fastener needs to be predrilled and that the stuff weighs a ton — what’s worse is the dust can take years off your life if you’re foolish enough to cut the wood inside without a mask or, better yet, a respirator. When machined, ipe emits clouds of green fog that seem insidiously resistant to dust collection and wreak havoc with the company computers, clothes, and lunches. Ipe splinters are barbed with microscopic fibers, making them easy to acquire and particularly bloody to remove. Still, it is incredibly strong and beautiful.

We plane and surface ipe decking to show its rich color and grain and to give it a certain glow — our decks look better than many interior floors I have seen. Finishing with teak oil, Penofin, Waterlox, or Sikkens brings out the luster and encourages the clients to have their decks maintained on a yearly basis — which is good for reliable income too. In the blazing sun on New York City rooftops, even those finishes don’t last long.

Up on the Roof
Once we arrive on site, the task is straightforward: We lay out the numbered pieces and assemble the grid. Since we’ve carefully measured the perimeter, as well as the locations of utilities, skylights, bulkheads, or other encumbrances, we know the deck will fit. Oftentimes we fit the deck with a soft transition to obstacles, maintaining the grid pattern and using gravel, riverstone, or plant material to fill in irregularly shaped spaces.

From the high point of the roof, we typically lift the deck one inch. We level the perimeter to that height, starting with the four corners and the center of each side; then we work our way between those points. Once the grid is leveled at 8-foot intervals, it’s rigid enough that we can put away the level and simply support the members at the half-lapped joints.

We always use an asphalt and fiber roof-protection board between the levelers and the surface of the roof. It’s important to consult with the building owner about this, since roof warranties stipulate the use of specific brands of protection board.

The levelers I’ve developed consist of pairs of marine-plywood ramps, coated with the same finish used on the decking and screwed to a plywood base so they’ll stand upright. The pairs are installed with their slopes running in opposite directions and are pushed together until the proper elevation is achieved. Then they’re screwed together to support the grid member in the valley where the ramps meet (Figure 5).

At this point we check the roof for any errant fasteners or debris. We vacuum out the drains for good measure and hose down the roof surface. Then, placing the panels takes about half an hour. In that time, a 1,000-square-foot roof transforms into a deck. This step never fails to amaze the clients. They see such a complete and sudden improvement they are instantly convinced that they have invested wisely.

The deck can be cleaned and refinished easily and is entirely modular and removable. If there’s a leak or if work needs to be done on the roof, the corresponding section of decking can be lifted out for access. If the clients move, the system can be disassembled and taken to their next home, where it can be altered to fit its new space. Best of all, it serves as an empty canvas; a foundation for designing and placing plant containers, pergolas, furniture, and whatever else one can imagine and build.

Ethan Ames is a deck builder in Brooklyn, N.Y., and Honesdale, Pa.