MN General Contractor common mistakes
MN General Contractor · Understand the traps and how to avoid them.
Skipping the pre-lien notice on a residential job and simply recording a lien statement at the end of the project.
Study material tends to emphasize the lien statement, so candidates treat the notice as optional paperwork, or assume only subcontractors and suppliers have to give notice.
What to do instead
At contract signing, open a notice file and calendar the trigger date: the pre-lien notice must be delivered to the owner personally or by certified mail before furnishing, or within 45 days after first furnishing labor, skill, or materials, and owner-occupied residential work triggers tighter notice rules. Keep proof of service; no provable notice means no enforceable lien.
Calculating the deadline to record a mechanic's lien statement from the contract date, the start of work, or substantial completion.
The contract date is the one date candidates reliably remember, and it feels like the natural anchor for all project deadlines.
What to do instead
Track a per-claimant 'last date of furnishing labor or materials' field and count 120 days from that date for recording the lien statement. Separately diary the one-year window after recording within which the lien must be foreclosed, and treat the two deadlines as independent clocks.
Doing extra work on a verbal 'we'll square it up later' and then answering exam questions as if any oral change is automatically unenforceable or automatically billable.
Jobsite culture runs on handshakes, so candidates import field habits into the exam and never learn the written-contract and change-order rules that govern residential work in Minnesota.
What to do instead
Know both sides: Minnesota requires residential contractor agreements to be in writing with specified disclosures and cancellation rights, and a signed change order should fix scope, price, and time impact before the work starts. On the exam, look for the answer that requires a written, signed modification rather than relying on memory or a verbal promise.
Adding a 20 percent 'markup' to job cost and reporting it as a 20 percent gross margin.
Contractors are trained to add a percentage to cost, and markup and margin are used interchangeably in the field even though they divide by different numbers.
What to do instead
Convert every pricing problem to one formula: margin equals (price minus cost) divided by price, while markup equals (price minus cost) divided by cost. A 20 percent margin requires a 25 percent markup; a 25 percent markup yields only a 20 percent margin. State which one the question is asking before computing.
Treating a profit on the income statement as available cash, and lumping equipment, insurance, and office overhead into direct job costs.
Owners who came up through the trades read their own job cost reports but rarely separate indirect overhead from direct cost or account for retainage and slow receivables.
What to do instead
Practice classifying each cost as direct job cost or overhead before answering, and remember that billed retainage and unpaid receivables are not cash. A job can show a healthy gross profit and still exhaust working capital; exam questions on financial distress usually turn on that distinction.
Answering code questions straight from the national model code text without applying Minnesota's amendments and chapter structure.
Most test-prep material is written for the IBC or IRC nationally, and candidates memorize those numbers because the model codes are the familiar reference.
What to do instead
Study the Minnesota State Building Code as adopted: know which occupancies and scopes fall under the commercial and residential chapters, that amendments override the model text, and that local amendments are limited. When a question's answer depends on a number, confirm it against the Minnesota-amended value, not the national one.
Detailing cold-climate assemblies from warm-climate memory, such as omitting a vapor retarder, placing it on the wrong side of the framing, footing above the local frost line, or guessing snow load.
Generic diagrams and national study guides show details that fail in a Minnesota winter, and candidates never connect ice damming, frost heave, and interior moisture to the code requirements.
What to do instead
Anchor the details to Minnesota conditions: vapor retarder on the warm-in-winter side with air sealing, ice-dam protection at eaves, footings below local frost depth (commonly 42 to 60 inches depending on location), and ground snow loads taken from the state's adopted load maps by county rather than assumed.
Answering safety questions on the assumption that federal OSHA rules apply unchanged and that a written safety program is never required.
Candidates study federal OSHA material and do not realize Minnesota operates its own approved state plan with additional requirements, including a written accident and injury reduction program for larger high-hazard employers.
What to do instead
Study MNOSHA as the enforcing authority for private and public construction in Minnesota, and learn the AWAIR written-program obligation separately from the federal standards. Where a state rule is stricter than the federal one, answer to the state rule.
Guessing at fall-protection and excavation trigger numbers, and assuming no one on site has to be designated as a competent person.
The numbers are similar across contexts (4 feet, 5 feet, 6 feet, 10 feet) and candidates memorize one threshold and apply it everywhere.
What to do instead
Sort the thresholds by hazard: fall protection in construction at 6 feet, excavation protective systems at 5 feet with daily competent-person inspections, ladders in trenches, and spoil piles kept back from the edge. Also memorize that the competent person is a named, trained individual with authority to stop work, not a job title.
Assuming a stormwater permit and pollution prevention plan are only needed at the federal 5-acre threshold, and scheduling excavation before a utility locate is complete.
The federal acreage figure is the best-known number, and on small residential lots the disturbance feels too minor to permit; utility locates get treated as a formality handled by the excavator.
What to do instead
Use Minnesota's 1-acre disturbance threshold for construction stormwater coverage, prepare the plan before disturbing soil, inspect weekly and within 24 hours of a half-inch rain, and stabilize disturbed areas on the state timetable. Separately, confirm a Gopher State One Call locate ticket with the required advance notice before any excavation, including small digs.