What is the standard distance from the string line used in masonry layout?

• A. 1/16 inch
• B. 1/8 inch
• C. 1/32 inch
• D. 1/4 inch

Answer: (A)

Using a string line as a guide in masonry layout keeps each course straight and the face of the wall true. The line is placed just off the finished face so that when bricks are bedded in mortar and the joints are struck, the outer surface ends up aligned with the line. A small offset of 1/16 inch is the standard because it provides just enough clearance for the mortar bed and tiny variations in brick size without letting the line drift or be shoved into the finished face. If the line sits farther away, the wall can deviate as you lay and finish; if it sits too close or directly on the face, the line can be disturbed by tools or mortar and fail to guide true alignment. Therefore, 1/16 inch is the practical balance that yields a straight, true-looking wall.