Construction scheduling and trade interfaces · Lesson 4 of 4

Construction scheduling and trade interfaces: defects, verification and case study

Two published interface failures, four questions for reading a failure, hold points and same-day records, the Last Planner promise record, and a case-study exercise.

You will be able to: Diagnose an interface defect, state its root cause in schedule and ownership terms, choose a corrective option, and document the evidence a reviewer needs.

11 min · 12 slides · 7 questions

All lessons in this module

Slide 1 of 12

What interface failures look like

In both cases a layer was missing or ended in the wrong place where two elements meet, and water got into the wall.

Reading a failure in schedule and ownership terms is this module’s own method, set out below; the two cases come first.

Sources

The Integration of Roof and Brick Requires Concise Details (Thomas W. Hutchinson, 21 November 2016) - Roofing Magazine
Failures: Costly consequences of skipping out on kick-out flashing (Kenneth Itle, 7 December 2023) - The Construction Specifier

Glossary

Hold point: In this module, a point where work stops for an inspection before the next trade covers it. In the Last Planner method such an inspection is a task on the weekly work plan, ahead of the next crew.
Through-wall flashing: Flashing installed through a masonry wall, for example between the top of a concrete foundation wall and the masonry above it. A Veterans Affairs specification has it installed continuous at such locations.
Kick-out flashing: A flashing at the end of a step flashing run that directs water away from the adjoining wall, so the step flashing does not concentrate water on the wall surface.
Plan Percent Complete: In the Last Planner method, the comparison of actual completions with promised completions, remembered as the percent of promises completed.
Workable backlog: In the Last Planner method, work from the next week or two that can be done in the coming week without being out of sequence or causing difficulty for other trades. It is not promised on the weekly plan.