Which option is acceptable as underlayment support under a buried mortar?

Which option is acceptable as underlayment support under a buried mortar?

• A. Concrete block
• B. Wood or flat rock
• C. Cardboard
• D. Gravel and sand

Answer: (B)

Underlayment support for a buried mortar must provide a flat, stable surface that evenly distributes the mortar’s weight and resists shifting as the ground settles. A flat rock or a flat, properly sized piece of wood can create that solid, level platform directly under the mortar tube, keeping it aligned and preventing loose soil from moving around the base. Cardboard would break down in moist soil, and loose materials like gravel and sand can shift or settle, losing the needed stability. Concrete blocks can also be rigid, but they may be difficult to fit precisely and can create uneven spots. So, a flat rock or a suitable piece of wood gives a consistent, stable base for burial.

Underlayment support for a buried mortar must provide a flat, stable surface that evenly distributes the mortar’s weight and resists shifting as the ground settles. A flat rock or a flat, properly sized piece of wood can create that solid, level platform directly under the mortar tube, keeping it aligned and preventing loose soil from moving around the base. Cardboard would break down in moist soil, and loose materials like gravel and sand can shift or settle, losing the needed stability. Concrete blocks can also be rigid, but they may be difficult to fit precisely and can create uneven spots. So, a flat rock or a suitable piece of wood gives a consistent, stable base for burial.