Waterproofing around tie-back heads and shoring elements on a blindside wall
The office-tower parkade has many anchor heads along its blindside wall. The waterproofing log says heads complete, but photographs cannot be connected to individual locations. One head differs from the approved typical detail and is about to disappear behind reinforcement.
Give each tie-back or shoring interruption a location number, current approved detail and review record before later work restricts access. Keep structural decisions about the anchor separate from waterproofing detailing. The soil-nail example below illustrates a system-specific treatment of a plate and shaft and explicitly leaves other layers out of its illustration. It is not a substitute detail for every tie-back, soldier pile, waler or different membrane assembly.
Turn many interruptions into identifiable records
- Make a numbered interface plan. Mark each relevant head and shoring interruption on the current elevation or location drawing. Use identifiers that can appear in photographs, reports and the crew’s work sheet without relying on someone remembering the order.
- Match each condition to an approved detail. Record the actual assembly and reference for the head, surrounding membrane and adjoining layers. Send a condition that differs from the typical drawing to the responsible technical people before treating it as covered by that drawing.
- Confirm structural status separately. Obtain the responsible engineer’s directions and required release for any relevant anchor work. The waterproofing crew must not loosen, cut, de-tension or otherwise alter a structural component to fit a membrane detail.
- Arrange the system-specific preparation. Have the qualified installer identify the approved components, substrate conditions and complete sequence. Check what an illustration omits, particularly adjacent layers or connections, instead of interpreting a simplified image as the entire assembly.
- Review while access remains. Coordinate the required checks before reinforcement or concrete limits visibility. Retain each head’s location, current condition, detail reference and any correction, keeping exceptions open until the authorized people resolve them.
- Hand over the numbered status. Give the concrete and reinforcing leads the released boundaries, protection requirements and outstanding interfaces. Keep later damage and required reassessment linked to the same identifier rather than issuing another unlocated heads-complete note.
Checklist
Each numbered interface needs
- Location and actual surrounding condition.
- Approved complete assembly reference.
- Relevant structural direction and release.
- Located installation and correction evidence.
- Required review and protection handover.
Check your understanding
A typical waterproofing image seems to fit, but the actual head has a different structural arrangement. What should happen before detailing it?
