Does a retaining wall always need weep holes?

Generally yes — some form of drainage relief, whether weep holes or an alternative drainage system, is a genuine, essential part of proper retaining wall design, managing water pressure that would otherwise build up behind the wall.

Skipping proper drainage is one of the most common genuine causes of retaining wall failure — water pressure behind an undrained wall significantly increases the load it needs to resist, well beyond what a well-drained wall of the same design experiences.

The specific drainage approach (weep holes, agricultural drain, drainage aggregate) is determined by your wall’s design, but some genuine drainage provision is essentially always part of a properly engineered retaining wall.

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