Many structures have at least a portion of it that is underground, or "below Grade". A multilevel parking structure, or a skyscraper, for example, have parking levels and storage areas that are underground.

Moisture typically comes into contact the concrete or cinderblock walls through the soil or dirt, and if the existing waterproof membrane has a failure, or if no membrane was installed in the first place, these walls can crack and blister.

For walls that can be exposed through excavation, a new waterproofing system can be installed. This usually consists of a synthetic rubber membrane either rolled, sprayed or simply attached to the wall, then a drainage mat, which acts as an initial barrier to the soil.

In cases where excavation is not possible or practical, foam or epoxy material can be injected into holes drilled into the wall in a grid pattern. When this foam material comes into contact with water, it expands to ten times its original size, and hardens, creating a waterproof barrier.

Urban Waterproofing uses Xypex, DeNeef, Sika, and CIM products for its below grade waterproofing projects.