A pre-construction soil application of termiticide to an area under a future concrete slab is called a what?

• A. Vertical barrier
• B. Horizontal barrier
• C. Crack-and-crevice barrier
• D. Moisture barrier

Answer: (B)

The main idea is creating a horizontal barrier. When termiticide is applied to the soil beneath a future concrete slab, it sits in the horizontal plane under the slab and forms a continuous chemical shield that termites would have to cross to reach the structure. This pre-construction treatment specifically targets subterranean termites before the slab is poured, making it a horizontal barrier. This differs from a vertical barrier, which is placed around the foundation to block termites from climbing upward, a crack-and-crevice barrier that is injected into concrete cracks and voids, and a moisture barrier, which focuses on reducing dampness rather than creating a termiticide shield.