Lesson 15: Review and Practice Exam

Reading

Fourteen lessons have covered the 2021 IRC provisions GCHS uses most on rehab and infill work, from the permit that starts a job to the smoke alarm that protects the people living in the finished house. This lesson does not introduce anything new. It walks back through the numbers that come up most often in the field, grouped the way an inspection actually moves through a house, so the practice questions that follow can pull from any of the fourteen lessons instead of just the last one. As always, local adoption governs, so treat every figure below as a starting point to confirm against the code edition your jurisdiction has adopted.

Administration, planning, and the site

A GCHS project starts with the administrative machinery from Lesson 1: a permit under R105.1, work exempt from that permit under R105.2, and the sequence of required inspections under R109 that decides when concrete, framing, and rough-in trades can be covered up. A permit becomes invalid if work is not commenced within 180 days of issuance, or if more than 180 days pass between inspections once work has started (R105.5). Lesson 2 then covers fire separation distance, measured perpendicular from a wall face to the lot line, which drives exterior wall rating and opening limits under Table R302.1(1), plus the duplex and townhouse separation requirements and the gypsum board assembly between an attached garage and the dwelling. Lesson 3 rounds out planning with the minimums that decide whether a space can be called a bedroom at all: floor area, ceiling height, light, ventilation, heating, and sanitation.

Foundations and moisture control

Lesson 4 sized footings from the soil beneath them: presumptive bearing values running from 1,500 psf for clay up to 12,000 psf for crystalline bedrock (Table R401.4.1), a 12-inch minimum footing depth below undisturbed grade or the local frost line, and the anchor bolts that tie the sill plate down. Lesson 5 picked up where the footing leaves off, at the foundation wall standing on it: how far the wall must clear finished grade, the drainage and dampproofing that keep soil moisture out, and the vent ratios that keep a crawl space dry from the inside.

Floor and deck framing

Lesson 6 covered the floor framing an inspector checks before the subfloor goes down: bearing length at supports, lateral restraint at joist ends, and the notching and boring limits that keep a plumber's drain line from cutting a joist's structural capacity in half. A notch is capped at one-sixth of a sawn joist's depth and is never allowed in the middle third of the span, where bending stress peaks; a bored hole is capped at one-third of the depth with 2 inches of edge clearance. Lesson 7 carried that same load-path thinking outdoors to concrete slabs and wood decks, where a ledger's fasteners, flashing, and a lateral load connection independent of the ledger bolts are what keep a deck from pulling away from the house under load.

Wall framing, headers, and bracing

Lesson 8 set the limits on how much of a stud can be removed for plumbing or wiring before it stops doing its job: 25 percent of the stud depth for a notch and 40 percent for a bored hole in a bearing wall, both relaxed in a non-bearing partition, plus the double top plate that ties the building together as a continuous tension ring. Lesson 9 separated two systems that live in the same wall but do entirely different jobs: headers, which carry gravity load around an opening down through jack studs, and braced wall panels, which carry lateral wind and seismic load down to the foundation. Parallel braced wall lines can be no more than 60 feet apart under the basic prescriptive wind-bracing limits, and adjacent braced wall panels on a line cannot be spaced more than 20 feet apart edge to edge.

Wall coverings, roof framing, and roof systems

Lesson 10 moved to the wall's skin: the drainage system behind anchored brick veneer, with its 1-inch minimum air space and weep holes spaced no more than 33 inches on center, and the layered sequencing that keeps flashing, water-resistive barrier, and siding shedding water outward instead of into the framing. Lesson 11 went up into the roof frame itself, where a ridge board is a nailing surface rather than a beam and the real work of holding a sloped roof's walls together falls to a rafter tie in the bottom third of the rafter height, resisting outward thrust, while a collar tie near the ridge resists wind uplift instead. Attic ventilation runs at 1/150 of the vented area, reducible to 1/300 with a qualifying high-and-low vent split. Lesson 12 finished the roof at its covering: asphalt shingles need a 2:12 minimum slope, a roof already carrying two layers cannot take a third without a full tear-off, and a masonry chimney has to clear its roof penetration by 3 feet and any part of the building within 10 feet by 2 feet, whichever is taller.

Life safety: egress, stairs, and alarms

The last two lessons cover the numbers enforced most strictly, because they govern how someone gets out of a house or survives a fall. Lesson 13 set the emergency escape and rescue opening every sleeping room and basement needs: 5.7 square feet of net clear area (5.0 for a grade-floor opening), with 24-inch height and 20-inch width floors that a compliant window has to clear by a real margin, plus the stair geometry, 7-3/4-inch maximum riser, 10-inch minimum tread, 6-foot-8-inch minimum headroom, and the guard required at 36 inches minimum height wherever a walking surface sits more than 30 inches above grade. Lesson 14 closed with smoke alarms in every sleeping room, outside each sleeping area, and on every additional story, carbon monoxide alarms outside each sleeping area, the hazardous-glazing locations near doors, wet areas, and stairs that require tempered or laminated safety glass, and the flame spread limits on interior finishes and insulation.

About the practice exam

This course's practice exam draws 60 questions at random from a bank spanning all seven domains covered across these fifteen lessons, with a 120-minute time limit and a suggested target of 70 percent correct. It is a practice tool GCHS built for its own staff development, not an official certification test, and passing it carries no credential beyond confirming your own readiness on this material. As with everything in this course, the locally adopted code, not this practice exam or any lesson in it, governs on an actual job.

Practice questions

Glossary

Presumptive load-bearing value

A default soil bearing capacity from Table R401.4.1, ranging from 1,500 psf for clay to 12,000 psf for crystalline bedrock, used in place of a geotechnical report.

Braced wall panel

An individual sheathed segment of a braced wall line that resists lateral wind and seismic load, distinct from the gravity load a header carries.

Emergency escape and rescue opening (EERO)

A window or door required in every sleeping room, basement, and habitable attic, checked separately for height, width, and net clear area.

Weep hole

A small opening at the base of a masonry veneer's air space that lets water collected by the flashing drain back to the exterior.

Fireblocking and draftstopping

Materials that close off concealed cavities against fire spread; fireblocking in stud and floor cavities, draftstopping in larger floor-ceiling voids.

3-2-10 rule

The chimney termination rule: at least 3 feet above the roof penetration point, and at least 2 feet higher than any part of the building within 10 feet.

Rafter tie

A ceiling joist or dedicated tie in the bottom third of the rafter height that resists the outward thrust of a sloped rafter pair, distinct from a collar tie near the ridge.

Guard

A protective barrier at an open-sided walking surface more than 30 inches above grade or floor, at least 36 inches high, limiting openings to a 4-inch sphere generally.