Material takeoffs and quantity reconciliation · Lesson 4 of 4

Material takeoffs and quantity reconciliation: defects, verification and case study

Nine takeoff defects with their checks and corrections, among them a wall height read as a flashing leg, a double count, a wrong unit scale, a count rounded down, a sheet count from area, and a girth with the wrong hem, plus what a reviewer should be able to rebuild.

You will be able to: Diagnose a takeoff defect from its symptom, name its cause, choose the check that proves it and the correction, and document evidence a reviewer can rebuild.

11 min · 12 slides · 6 questions

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Slide 1 of 12

Anatomy of a takeoff defect

A takeoff defect is described in four parts: the symptom a reviewer sees, its cause, the check that proves it and the correction.

Each correction is recorded with the evidence that the check now passes.

A wrong number looks as tidy as a right one, so the check matters more than the look.

Sources

AFS Design Center: Material Takeoff and Nesting method (quantities and weights, never prices) - Architectural Flashing Supply

Glossary

Attribution: Deciding which drawn element a dimension measures. In AFS's drawing takeoff a dimension on a building element, or one that cannot be attributed to the flashing, is never a flashing leg.
Coil piece: A piece longer than 10 ft. AFS's Material Takeoff tool lists it apart from the sheet strips and gives an error for one over 126 in.
Confidence: The high, medium or low tag AFS's takeoff puts on each item it reads. Anything not high is flagged for a person to check.
Hem allowance: The extra flat width a hem uses. FlashDraft's figure is approximate: an open 0.5 in hem with a 1/8 in gap adds 1.125 in and a smashed 0.5 in hem adds 1 in.