Stone Layout: Reading Drawings, Coursing, and Dry-Stack Planning

Why Layout Comes Before Mortar

Every hour you spend planning a stone wall on paper and on the floor saves multiple hours of teardown and rebuilding once mortar sets. A dry-stack layout—placing units without mortar—lets you audition your entire pattern, catch problems with unit size variation, and confirm that coursing heights, head joints, and bond all work before anything becomes permanent. This lesson teaches you to read a masonry working drawing, extract the numbers you need, and translate those numbers into a precise physical layout.

Reading a Masonry Working Drawing

A masonry working drawing for a stone wall typically includes a plan view (looking straight down), an elevation view (looking straight at the face), and sometimes a section view (a vertical slice through the wall). For coursed ashlar work, the elevation is your primary reference: it shows the wall height, overall width, course heights, mortar joint thickness, and the bond pattern.

Using a Scale Rule

Architectural drawings in the US are usually drawn at a stated scale such as 1/4" = 1′-0" or 1/8" = 1′-0". A triangular scale rule has multiple scale edges. Line up the correct scale, place the zero at one end of the feature you are measuring, and read the dimension directly in feet and inches. Always confirm the scale against a noted dimension on the drawing before you trust your measurements—drawings can be printed at a size different from the original.

What to Extract from the Elevation

For a coursed ashlar wall you need: overall wall width, overall wall height, number of courses, height of each course (stone unit height plus joint thickness), and the length of a typical unit. From those numbers you can build a materials list and a story pole.

The Story Pole

A story pole (also called a storey rod or gauge rod) is a straight piece of wood or aluminum with course heights marked on it at full scale. Once you set your first course, you hold the story pole against the wall and transfer each course line directly—no repeated measuring and no accumulation of small errors. Mark both the bottom and top of each stone unit and label the joint lines clearly. The story pole is one of the most valuable layout tools in the trade.

Coursing and Bond Pattern Rules

Consistent course height is the first rule of coursed ashlar: every course must be the same height (unit + joint). Even small deviations add up over a tall wall.

Bond pattern is the rule about how head joints (vertical joints between units in the same course) line up from course to course. The most important rule: avoid continuous vertical joints, sometimes called a stack bond. A continuous vertical joint running through two or more courses creates a structural weak plane. In a running bond or ashlar pattern, the head joint of one course should fall near the center of the unit above or below it—offset by at least one-third of the unit length is the standard minimum practice.

Planning head joint placement begins on paper. Sketch each course on graph paper or your drawing, noting where each head joint falls. When you move to the floor layout, start with a chalk line for the wall base, set your end units first, then fill in the field, adjusting unit position to keep head joints staggered.

Safety in the Stone Lab

Stone units are heavy. Even a small ashlar block can cause a crush injury to fingers or feet.

• Foot protection: Wear ANSI-rated safety-toe boots at all times in the lab. No exceptions.
• Eye protection: Safety glasses or goggles protect against chips when stone edges contact each other.
• Back safety: Use proper lift technique—bend at the knees, keep the load close to your body, get a partner for units over 50 lb. Never twist while lifting.
• Housekeeping: Keep your layout area clear of loose chips and tools you are not using. A trip over a misplaced tool while carrying stone is a serious injury event.
• Chalk lines: Snap chalk lines away from your face and eyes, and announce to nearby students before snapping.

Checking Plumb and Level

After laying each course, check your work at four locations along the 4-foot run:

1. Level: Rest a 4-foot level on top of the course and read the bubble. A tolerance of 1/8 inch over 4 feet is tight—it means the wall top is nearly perfectly horizontal.

2. Plumb: Hold the level vertically against the face of the wall, or use a plumb bob hung from the top edge. A plumb bob never lies: gravity always pulls the string perfectly vertical. Record the gap between the string and the face at top and bottom.

Record every reading on your layout log before you make any adjustment. Your log is the paper trail that proves the wall meets tolerance and it becomes your reference when mortar work begins next session.

Calculating Unit Quantities

To estimate units needed: divide the wall area (length × height) by the area of one unit face (unit length × unit height), then add a waste factor. For a cut-stone ashlar job on a simple rectangular wall, a 5–10% waste factor is typical for a beginner; an experienced mason may use less. Always round up to whole units when ordering.