Wall leaks, especially in poured concrete walls, generally occur around poorly sealed openings in the foundation or through cracks and/or seams.
Poorly sealed openings are commonly found around water/wellpipes, sewer/septic pipes, form ties (the small metal rods that are found in rows on the wall), and electric/well pump wires.
A properly prepared surface and a two-part patch consisting of hydraulic cement followed by a plaster coat will solve many of these leaks.
However, it is often necessary to dig up the problem area and patch it from the outside.
Generally, the smaller and higher up on a wall a leak is, the easier it is to successfully patch from the inside.
Conversely, the lower and larger leaks should be repaired from the outside. Part of the reason behind this approach is that when you patch from the inside, water still gets into the concrete wall and you are stopping it at the inside surface. When the patch is low on the wall it is subjected to greater pressure acting to push the patch off the wall.
When patched from the outside, a tar coat and a poly vapor barrier are added to the patch and the water is kept from entering the wall entirely. Often an inside patch that is holding back a lot of water will show signs of dampness, since the water is just an inch or so away.
This dampness is non-existent with an outside patch. Careful attention is the key to spotting these types of leaks. Many of them only leak for a short period of time and often, when they are low on the wall, don't start leaking until many hours after the rain has started.
Check frequently with good lighting and use your hand to feel the wall and theunder sides of pipes. Sometimes making a heavy chalk line under something you suspect is leaking will cause water to leave a run mark and help in identification. Surface preparation is the key to proper, successful patching and the reason a professional should be used in most cases.
We have the pneumatic tools for chiseling out the area to be patched and chipping scarifying the surrounding area. The entire area is then wire brushed, acid washed and rinsed and the various patch coats applied.
Eastern Waterproofing Co., Inc. would be happy to quote this type of work for you and provide references and a free written proposal.