What Does Water Ponding Mean?
Water ponding is the accumulation of water on flat surfaces such as slab-on-grade, flat decks, driveways or balconies. This can occur due to water seeping upward from inside (or below) the surface, or its source can be external, such as rainwater.
During the installation of slab-on-grade foundations, the plumbing is laid out prior to pouring the concrete. Once the slab is poured, the piping is encased either in the soil beneath the slab or, in some cases, within the slab itself. As a result, cracks, leaks, bursts or other problems can often go undetected until physically manifesting on the surface of the slab. This unwanted pooling of water can cause damage to the slab material and the structure itself.
Water ponding is also known as water pooling.
Trenchlesspedia Explains Water Ponding
Water ponding can occur due to improper drainage of rainwater from the surface, seepage of groundwater or leakage from pipes installed below the surface.
Ponding or pooling of water on the surface of the slab is almost always a sign of a leak. Concrete is a solid material, but is porous and consists of tiny spaces or holes that allow liquids or gases to pass through. Water accumulating on the underside of the foundation looks for an escape route, usually permeating through the concrete slab and manifesting as excessive water on the surface. Water that does not immediately penetrate the slab may be found near walls outside the building structure.
Unattended leaks on a slab-on-grade can be detrimental to the structural integrity of the slab and the supported structure. Leaks can be located by video inspection of pipelines, which can be carried out without disturbing the surface. Once the problem is located, trenchless rehabilitation can be used to repair pipes under the slab-on-grade foundations using methods such as pipe bursting, cured-in-place pipe (CIPP) and sliplining.