Key Takeaways
- Trade-specific checklists ensure consistent quality across projects and inspectors.
- Framing tolerances are measurable—plumb within 1/8″ per 4 ft, level within 1/4″ per 10 ft.
- MEP quality points focus on safety-critical items: connections, protection, pressure.
- Finish quality standards must match lighting conditions and market expectations.
Trade-specific checklists standardize quality expectations and ensure consistent inspection across projects. Each trade has critical quality points that determine long-term performance.
Demolition and Site Prep QC
Checklist items: complete removal of specified materials, structural elements preserved per plans, hazmat protocols followed (lead, asbestos), utilities properly capped/disconnected, subfloor condition documented, hidden conditions documented with photos, debris removed and site clean. Critical: document everything revealed during demo—conditions change the scope.
Framing QC
Checklist items: walls plumb (within 1/8″ per 4 ft), floors level (within 1/4″ per 10 ft), square corners (3-4-5 method), proper fastener schedule, connectors per engineering, blocking for cabinets/fixtures/grab bars, fire blocking at required locations, proper header sizes, nail plates on notched/drilled members.
| Check Point | Tolerance | Method |
|---|---|---|
| Wall plumb | 1/8″ per 4 ft | 4 ft level |
| Floor level | 1/4″ per 10 ft | 6 ft level + string line |
| Square | 1/16″ per diagonal foot | 3-4-5 method or diagonal measurement |
| Stud spacing | ±1/4″ from layout | Tape measure |
| Header size | Per span table/engineering | Visual + tape measure |
Framing quality tolerances
MEP (Mechanical, Electrical, Plumbing) QC
Electrical: wire sizing per circuit load, proper connections (no backstabs in critical locations), AFCI/GFCI per code, box fill calculations, panel labeling. Plumbing: slope verification (1/4″/ft minimum for drains), pressure test (hold 40 psi for 30 minutes), venting within code distances, supply line insulation. HVAC: duct sizing per Manual D, sealed connections, proper refrigerant charge, return air pathways.
Finish QC
Drywall: smooth finish appropriate for lighting conditions (Level 4 minimum for paint, Level 5 for critical areas), no nail pops, tight joints, proper corner bead. Paint: consistent sheen, no holidays (missed spots), clean cut lines, proper dry film thickness. Flooring: consistent seams, no lippage (>1/32″), proper expansion gaps, pattern alignment. Tile: consistent grout joints (±1/16″), level (lippage <1/32″), proper thinset coverage (>95% on walls, >80% on floors).
Risk Scoring Matrix
Sources
Common Mistakes to Avoid
Not performing a pressure test on plumbing before closing walls
Consequence: Hidden leaks cause water damage, mold, and structural deterioration discovered only after significant damage has occurred
Correction: Require and verify a pressure test (static test at 60 PSI for 15 minutes with no drop) before any plumbing is covered
Test Your Knowledge
1.What is the most important QC checkpoint for plumbing work?
2.What electrical QC check prevents the most common residential fire hazard?