Because concrete is porous, you’ll be able to typically see wet streaks that permit you recognize wherever the water is returning in. rummage around for streaks on cracks, at the corners of windows, between mortar joints (for cement block walls), and around pipes wherever they enter or exits, like a water system line or a sewer pipe. If entire wall surfaces square measure wet, however, you’ll ought to do additional police work. To conduct a straightforward condensation take a look at, dry a region of the wall with a rag so attach a one-foot sq. piece of tin foil to the wall with adhesive tape. Peel off the foil when twenty four hours and check however the bottom of the foil feels. If it’s wet, water is oozing through the wall from the surface. If dry, the wetness is originating elsewhere within the basement, possibly from a basement shower—easily remedied by putting in a vent fan within the lavatory to direct steam outdoors.