Matthew Carroll Navey

Sometimes, in a building project, the most creative part of the job is figuring out how to stage the scaffolding. After that, the actual work can be pretty routine. With masonry, doing the layout and setting guide lines are often the most creative and challenging—and critical—parts of the job. The actual task of laying the brick can be mundane by comparison. That was the case with a set of freestanding brick stairs that I built recently.

Though the masonry skills (mixing mortar, troweling, and brick laying) required for the stairs were routine, the layout was involved. Executing that layout required setting up the lines in some creative ways, and getting those lines correct and then following them precisely was essential to the success of the stairway.

Trade Comparisons

Although masonry makes up most of the work that I do, I’m lucky to have spent a lot of time as a renovation carpenter. The biggest difference between carpentry layout and masonry layout is that the latter is three-dimensional. Carpenters, roofers, and siders usually work in two dimensions, marking their layouts with chalk lines on flat surfaces.

Masons occasionally snap chalk lines, but most of the time, our lines stretch across open space. We often build a small part of a structure on each end and then set a string across to fill in the space between. Sometimes we set up brackets to hold the lines, as I did in several places on this stair project.

Masonry layout typically starts at the top. For example, when laying out brick veneer on a house, the mason establishes a top line about 4 3/4 inches below the sills of the first-story windows (the thickness of a brick sill sloped to shed water). The mason then measures down from that line to lay out the veneer. For this stair project, the layout started at the porch floor elevation. That height determined the height of the slab base as well as the elevation of each step.

Masonry layout is driven by three-dimensional unit sizes (brick and block), especially the height of the units. For these stairs, the rise of 6 5/8 inches was determined by the height of one course of stretchers (2 5/8 inches) plus one course of rowlocks (4 inches). By adjusting the mortar thickness, I can adjust the rise by 1/8 inch higher or lower, but without ripping bricks lengthwise (which is hugely labor intensive), I was limited by those dimensions. (I also could have used three courses of stretchers for an 8-inch rise, plus or minus 1/8 inch). Contrast this with laying out wood stair stringers, where riser-tread combinations are almost unlimited.

Other Layout Oddities

Prudent carpenters would never lay out studs on a wall plate one at a time with a framing square. If they did so and were off by just a tiny amount on each one, they could gain or lose length over the course of the layout, which would make the plywood or drywall break incorrectly. Masons, on the other hand, use cumulative gain or loss to their advantage. We deliberately adjust the thickness of mortar joints so that the brickwork grows or shrinks to fit a given space or length. I used this cumulative gain with the rowlock course for each step on this staircase. The tool we use to lay out for cumulative gain or loss is a brick-spacing ruler.

The last big difference between masonry and carpentry layout is that exterior masonry must be pitched to shed water. While wood stairs and decks are typically pitched slightly, it’s a more critical detail with masonry. Water drains through the spaces of wood treads and decks, but masonry surfaces are solid and water must flow off of them readily. For this reason, the pitch of a masonry surface (1/4 inch per foot) is steeper than carpentry projects usually require.

This article walks you through each phase of building these stairs, focusing primarily on the layout involved. There is a lot more to masonry work than meets the average eye.