Guide · Updated 2026-10-30

Michigan Ductwork exam guide

Practice for the Michigan Ductwork mechanical contractor exam: duct construction, installation and support, system design, plenums, exhaust systems, and chimneys and vents.

The format

55 questions
60 minutes
75% to pass
Open book LARA reference list
Exam fee: $50 (PSI).

Test-day rules

Computer-based at PSI test centers, after LARA approves your application.
Open book: bring unmarked, bound copies of the references LARA lists for this classification.
Questions on PA 407 (the Skilled Trades Regulation Act) and PA 230 appear on every classification exam.

What’s on it

PSI lists the content areas but not how many questions come from each. Our practice uses these estimated weights:

Topic	Our estimated weight	In our mock	Bank
Michigan law (PA 407 Article 8, PA 230) Licensing (PA 407) Permits (PA 230) Local registration (PA 407) Penalties (PA 230) Complaints (PA 407)	9%	5	7
Duct construction and materials Duct materials Underground ducts Pressure classes Seams and joints	20%	11	15
Duct installation, support, sealing, and insulation Supports Condensation Insulation Clearances Access Registers Testing Installation	16%	9	12
Duct design and sizing (Manual D) Airflow math Fan laws Manual D Air changes Static pressure	16%	9	13
Plenums, fire/smoke dampers, and smoke detection Plenums Smoke detection Fire dampers Smoke dampers	13%	7	11
Exhaust systems (dryer, environmental, kitchen) Dryer exhaust Exhaust termination Kitchen exhaust	14%	8	12
Chimneys, vents, and vent connectors Chimney height Gas vents Vent connectors Common venting Vent terminals	12%	6	10

A study plan

Know duct construction tables: gauges, joints, and reinforcement.
Review support spacing, clearances, and fire damper rules.
Study plenum materials and exhaust duct rules (dryer, kitchen, bath).
Learn chimney and vent connector basics.
Take timed mocks at about a minute per question.

Try 10 free Ductwork questions Ductwork practice page

Sources: PSI Candidate Information Bulletin 5421 (mechanical, effective Aug 20, 2026) · LARA mechanical exam reference materials (PDF). Checked October 30, 2026. Rules and fees change, so confirm with LARA and PSI.

FAQ

How many questions are on the Ductwork exam?

PSI’s bulletin lists 55 questions in 60 minutes, open book, with 75% to pass.

What does it cost?

PSI lists $50.

MI Trade Prep is an independent study tool, not affiliated with LARA or PSI.