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Pic 1 shows the newly constructed basement (Just 4 days) wall and It can clearly seen the crack across the wall (Not sure whether its crack or not but looks like) due to pouring concrete. I wonder this is going to be a major problem and caused to seepage water in to the basement. I can see similar crack in another location as shown in the picture 2. I would appreciate advice and comment on this.

Thanks

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Those are not cracks. It is where the concrete was poured and had a chance to set for a while, perhaps while another part of the foundation was being poured. The concrete chute or hose then returned to the area in question, and resumed pouring, allowing the coarser aggregate to show at the joint.

It may also be a cold joint, where concrete was started, then finished later in the day or a different day.

It may also be where the concrete was not vibrated enough in the area to settle in the coarse aggregate. Vibrating concrete helps eliminate air pockets along the form walls. Sometimes air gets trapped, creating what is called "honeycombing"

Any of these conditions although not great, since they are really small, will not create leaks in the basement. Concrete is a big sponge anyway, soaking up moisture, and releasing it to the dryer side, always trying to find equilibrium. The foundation needs a good layer of foundation coat to keep water at bay.

  • Thanks Jack, This is relay helpful. Even though it is small, is that required any repair? do you think this kind of cold joint is pretty normal in the basement? I appropriate your help on this matter. – sam Jun 7 '15 at 1:21
  • I have seen it a lot, and over much larger areas. As long as the rebar is still well imbedded, there is no structural issues. No repair is needed. – Jack Jun 7 '15 at 3:51
  • jack how about if they go from window to window on both sides of the wall – user44006 Sep 28 '15 at 7:47
  • @ Ken Nunn, if you have the same situation and it is a new pour, as well as no rebar showing, it may be ok. If you could get a picture up would really be helpful. – Jack Sep 29 '15 at 2:21
  • I fully agree that the difference was from not vibrating enough. Vibrating helps to eliminate air voids and mixes the separate layers of the pour+ – Ed Beal Jul 12 '18 at 14:50
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It would be better to instal a polythene sheeting all round the outside walls of the foundation to guarantee that no water will ever find its way in any possible cracks.

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