Weep Holes in Building Foundation Wall

[TN Engineer]

I'm designing a retaining wall that is part of a building foundation, to address the low grade at the exterior of the building. This is not a basement wall. The main interior floor slab-on-grade is a few feet higher than the exterior grade, thus the need for a cast-in-place concrete retaining wall to support the building. In this case, I am wondering if it is typical (or necessary) to include weep holes in the wall. Given that the retained soil side of the wall is under interior space, direct rainwater collection should not be an issue. I suppose we can include the weep holes, just to be on the safe side (to address any potential rises in groundwater, flooding, etc.), but I'm curious if this is conservative, or if weep holes (or some other drainage system) is typical in these situations where the retained side of the wall is interior space. Thanks.

 

[phamENG]

I've never seen it done, and this is a popular foundation system in my area.

 

[XR250]

Many contractors around here install a 4" perforated pipe at the interior base and exit it thru the wall.
I think it is a good idea.

 

[dik]

Similar here, but a solid pipe with a screen at the inside end to prevent 'critters' and about 4' o/c.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[haynewp]

Check the ground water table level in the geotech report if you have one, keep in mind the level can fluctuate during the year.

 

[JAE]

I'd also consider using a filter fabric if you use a perforated pipe behind your wall (and below the interior floor slab). Any moisture that does occur inside (if any) could potentially erode down the pipe and cause settlements - possibly.

 

[dik]

... and the rate of percolation.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik