Honeycomb or Rock Pockets are areas in the foundation where the creamy part of the cement has not filled in. These areas are characterized by exposed rock / aggregate where water can leak through. If these areas are not grouted on the outside of the foundation and then properly coated they can cause leaks.

Ways To Minimize Honeycomb:

My New Foundation Has Honeycomb What Now?

Honeycomb is more common then you might think. It is relatively easy to prevent future problems by:

How We Fix Honeycomb in Existing Structures: