Answer: In most cases
Explanation: Not all retaining walls require weep holes, but they can be beneficial in certain situations.
Weep holes are small openings that are typically placed at the bottom of a retaining wall to allow water to drain out. They can be particularly useful in situations where water buildup could cause hydrostatic pressure, which can cause the retaining wall to become unstable or fail.
If you are building a retaining wall in an area that experiences heavy rainfall or water buildup, weep holes can help prevent hydrostatic pressure from building up behind the wall. This can help reduce the risk of structural damage to the wall and prevent water from seeping into the ground and causing soil erosion.
However, if your retaining wall is built on a slope that naturally drains water away from the wall, or if you have installed adequate drainage behind the wall, weep holes may not be necessary. It is always a good idea to consult with a structural engineer or other qualified professional to determine whether weep holes are necessary for your specific situation.