A hairline crack in my 9 month old foundation just started letting in water. The water kind of bubbles up at a very slow rate, runs down the side into the sump system of my floating slab floor. My builder will 'fix' this by having his contractor come in and inject epoxy into the crack (from the inside). I have always been told to fix water issues from the outside so what do you guys think. Should I let my builder do this or is this generally a bad idea? If I let my builder do this now, I will most likely have the exterior dug out and fixed before I put my deck on in the srping. How should I have the exterior fixed (it currently has the black dampproofing on it)?