What is considered an under slab hazard?

An under slab hazard refers to potential risks or issues that exist beneath the concrete slab of a building. Water supply lines represent one of these hazards because if they leak or break, they can lead to water accumulation beneath the slab, which may contribute to mold growth, structural damage, and even create conditions that allow for the infiltration of radon gas. The presence of water can also promote corrosion of other materials, leading to further complications.

While the other options could present various health or safety issues within a property, they do not specifically relate to the risks associated with the under slab environment in the same way that water supply lines do. For example, pests may cause damage or health concerns, and electric wiring, while important, poses risks above the slab rather than beneath it. Open trenches can indicate construction hazards but are not typically a permanent concern associated with structures that have established slabs. Therefore, the water supply lines are highlighted as the primary concern when discussing under slab hazards.