How many ledger panels do you need?

What one panel covers

A ledger panel is measured by its face: the height times the length you see on the wall. The staggered ends of each panel lock into the next one, so the face area is the whole of what it covers — nothing is lost to overlap.

A 6 × 24 inch panel covers 6 × 24 = 144 square inches, which is exactly one square foot. A 6 × 18 panel covers 0.75 sq ft and a 6 × 12 panel covers 0.5 sq ft. In metric, a 15 × 60 cm panel covers 0.09 m², so about eleven panels make a square metre.

Measure the wall

Multiply the height of the wall by its width, in feet, for the area in square feet. Then subtract anything that will not be covered: a window, a door, a fireplace opening, a television recess. Measure each opening the same way and take it off.

A wall 10 feet wide and 8 feet high is 80 sq ft. With a fireplace opening of 3 × 3 feet, the stone covers 80 − 9 = 71 sq ft.

Add for cutting

Panels are cut at the ends of every row, around openings and at the ceiling line. Add 10 percent for a plain rectangular wall and 15 percent for a wall with several openings, an arch or a sloped ceiling.

For the 71 sq ft wall above, 71 × 1.10 = 78 sq ft, so 78 panels of 6 × 24, or 156 panels of 6 × 12.

Corners

Where two stone walls meet at an outside corner, the edge has to be finished. It can be done with matching corner pieces, or by mitring the ends of flat panels on site. Either way, measure the height of every outside corner separately, so the corners are quoted and not discovered on the day.

From square feet to crates

A buyer filling a container works the other way round: from the crates that fit to the square feet they hold. Natural stone is heavy, so a 20 ft container usually reaches its weight limit long before it is full, which is why stone ships in 20 ft containers rather than 40s. Ask for the square feet per crate and the crates per container with your quote, and you have both numbers for your own price list.