Concrete Foundation Walls - Water Leakage

Problem: Water leakage through foundations - 3.

Cause: Leakage through form-tie holes.

When forms are stripped, the paths created by the ties used to hold the forms in position, to create the foundation wall, can provide a ready path for water entry when the wall is not adequately sealed.

Solutions: Waterproof form-tie holes and other repaired areas before applying damp-proofing.

• Prevent voids below form-ties with good placement and consolidation techniques.
• Cut back tie-holes and other repaired areas by a minimum of 5/8 inch (15 mm) as shown in Figure 25.

Figure 26 - Form-Tie Patching

• All form-ties shall be removed at least flush with the concrete surface.

• Concrete walls to be waterproofed shall have all holes and recesses resulting from removal of form-ties sealed with mortar or waterproofing material.

• The majority of foundation leakage occurs through form-ties. Therefore, parging over form-ties is also recommended before damp-proofing.

• Ensure that patches are installed flush to the foundation wall to prevent damage during backfill.