concrete pour interface

[jxzohio]

There is a new construction house which I want to purchase. But on the basement walls, I found a long horizontal line (quite obvious) which I believe is due to different concrete pours. The line is about 25 feet long and 3 to 4 feet above basement floor. I am quite concerned about the possible leakage in the future through the interface of different concrete pours. Is this a potential problem in the future? Does the interface undermine the integrity of the basement wall? Thanks.

 

[jjeng2]

The line could be a mark from a form. This is more common to see than a joint from two pours. If the two pours were done properly and the wall was designed right and you have adequate waterproofing and drainage, it shouldnt be a problem. The exterior of the wall will be in compression and tend to close any possible cracks/joints. I would keep an eye on it though, since you are not sure what it is. Look for cracks and leaks and check for bulging and tilt with a level and plumb bob periodically.

 

[RHB51]

A form joint will be perfectly horizontal and will probably have a slight bulge where the concrete leaks
between form edges. Rarely have I seen residential basements being formed with anything less than an 8' tall panel; therefore with the information given I would suspect it is a cold joint (common as dirt in residential).

If the line is slightly wavy or slopes slightly with a different coloration it is probably a cold joint.
Seeing how so many residential basements have cold joints and they are within limits of plain concrete per ACI then you probably won't have a problem with leakage since the outside is in compression.

The typical problem that occurs some years later is when the soil is super saturated and will actually cause the wall to move in at the top or crack at mid-height.
On any house; be sure and maintain positive drainage from the house; do not let water run towards the house.