A chemical barrier around the base of foundations and back-filled soil against foundation walls is called a what?

• A. Vertical barrier
• B. Horizontal barrier
• C. Liquid barrier
• D. Soil barrier

Answer: (A)

Barriers are described by their orientation relative to the foundation, and this one is vertical because it runs around the base of the foundation and into the backfilled soil against the foundation walls, forming a continuous shield that rises along the wall. A vertical barrier specifically targets the pathway up the foundation from the soil, making it the best match for the scenario described. In contrast, a horizontal barrier would be placed in a horizontal plane around the exterior soil, not hugging the wall; a liquid barrier refers to the chemical treatment itself rather than its orientation; a soil barrier is too general and does not specify the barrier’s vertical positioning against the foundation walls.