The plastic pipe leading from the water main to my townhouse cracked and was replaced with copper several years ago. But after about a year, following rain, there is a slight drip on the bottom of the 1 inch copper pipe and the cement in my basement. It appears the rain water is seeping in along the pipe. It there any treatment I can make inside the basement to seal this?
You might be sucessful in sealing around the pipe with a hydraulic type cement or coating made for sealing concrete blocks but this would probably only work if the wall is a retaining type wall that has been poured with solid concrete within. If the water is only coming in right around the pipe this may work but if it is seeping through the mortar joints then you will probably have to dig down outside and reseal around the pipe. That is the best way to do it anyhow since it sounds like the water barrier or membrane has been damaged. Clean the area around the pipe after you dig it out and let it dry good and then you can seal it with roofing cement. Make sure you get roofing cement instead of roof coating since the cement is thick and roof coating is too thin. If the pipe has been inserted into a sleeve ,(usually a larger piece of pipe that protects the main water line from direct concrete exposure as it penetrates the wall)make sure that it too is sealed where the main water line enters it. Hope this helps!