Orientation · General Building (B) · Finish Trades
Finish Trades: Where the Job Gets Judged
About 6 minutes · 5 sections
What this guide covers
Finish is what the owner sees, touches, and complains about — the last fifth of the work carrying most of the opinions. This section spans seven clusters, from paint and tile through drywall, windows, and the landscaping around the finished house. The exam's angle is the supervisor's: what makes a finish fail, and which hidden layer the visible surface depends on. The code reaches into finish work in a handful of places — wet walls, glass where people can walk into it, the window a sleeping room may need to escape through, and the ground that must carry water away from the building. Skim the clusters you work daily and spend your time where your experience is thin. Closed book, as always: what the code requires behind the tile has to be carried in, not looked up.
The rules the exam tests
Finish Trades, from painting to landscaping, is about 20 percent of the General Building (B) exam.
Finish Trades includes painting, staining, coating, and interior wall covering; tile and stone; floor covering; cabinetry and ; plaster, drywall, and ceilings; windows, skylights, and doors; and landscaping. The section is about 20 percent of the General Building (B) examination, and the guide's footnote says its percentages are approximate.
On the job
Seven clusters — organize your study by the guide's own list, and notice how many are pure craft: the code reaches finish work in a few specific places, and the rest is practice the trade references teach.
Exact wording
The Finish Trades section is approximately 20 percent of the General Building (B) examination — the guide's percentages are approximate by its own footnote — and covers painting, staining, coating, and interior wall covering, tile and stone, floor covering, cabinetry and millwork, plaster, drywall, and ceilings, windows, skylights, and doors, and landscaping.
CSLB General Building (B) Examination Study Guide — s04-finish-trades
The examination is closed-book. You answer every question from memory.
No reference materials of any kind may be used during the examination — the code book, your notes, a printed table, none of it. That is what closed-book means, so what you would look up on the job you carry in.
On the job
On the job the code book is always within reach; in the exam room it is not. What you would normally look up, you have to carry in.
Exact wording
The examination is closed-book: no reference materials may be used during the examination.
CSLB General Building (B) Examination Study Guide — test-policy
Each question on the examination has four choices and one best answer.
Some examination questions require mathematical computation, and a calculator is provided, so you work those on the calculator rather than from memory. The examination is written to provide only one best answer, so read all four choices before you choose.
On the job
BEST answer means more than one choice can be partly right — and the computation questions (areas, volumes, material quantities) are worked with the provided calculator, not from memory.
Exact wording
The examination is multiple-choice with four choices per question, written to provide only one BEST answer; some questions require mathematical computation, and a calculator is provided.
CSLB General Building (B) Examination Study Guide — test-strategy
Install interior coverings and wall finishes to Chapter 7 of the California Residential Code.
The California Residential Code puts the wall-covering rules in Chapter 7, and the chapter's tables count as part of the requirement. Because the exterior covering rules sit in that same chapter, one lookup serves both sides of the wall.
On the job
Plaster, drywall, and tile backing all route to one chapter — knowing that is the lookup skeleton for three of this section's clusters.
Exact wording
Under the California Residential Code, interior coverings and wall finishes are installed in accordance with the wall-covering chapter (Chapter 7) and its tables — the same chapter that carries the exterior covering rules.
Residential Code § r702.1
Back tub and shower wall tile with a listed . Water-resistant gypsum is not one.
Under the California Residential Code, backers for wall tile in tub and shower areas and wall panels in shower areas must be listed backer-board materials. Never use water-resistant gypsum backing board where there will be direct exposure to water or in areas subject to continuous high humidity.
On the job
The classic wet-wall mistake: water-resistant gypsum sounds like a shower product, and the code says it is exactly what a shower wall may not rely on where water hits directly.
Exact wording
Under the California Residential Code, backers for wall tile in tub and shower areas and wall panels in shower areas must be of the code's listed backer-board materials — and water-resistant gypsum backing board must not be used where there will be direct exposure to water or in areas subject to continuous high humidity.
Residential Code § r702
You must use in swinging, sliding, and bifold doors.
Swinging, sliding, and bifold doors are among the California Residential Code's specifically enumerated hazardous locations, and glazing there must pass the human-impact test requirements, subject to the listed exceptions — an opening a 3-inch sphere cannot pass through, or decorative glazing.
On the job
The code decides where glass must be safe by LIST, not by judgment — the enumerated locations are the tested content, and annealed glass in one of them is the defect to spot.
Exact wording
Under the California Residential Code, glazing in the code's specifically enumerated hazardous locations — glazing in swinging, sliding, and bifold doors among them — must pass the human-impact test requirements, subject to the listed exceptions, such as openings a 3-inch sphere cannot pass through and decorative glazing.
Residential Code § r324
You must provide an emergency escape and rescue opening in every sleeping room.
Basements, habitable attics, and the room a sleeping loft opens to each need at least one operable emergency escape and rescue opening too. Each opening must open directly into a public way, or into a yard or court that opens to one. Exceptions apply, such as basements with ceilings lower than the stated height.
On the job
A bedroom window can be a life-safety component — which is why replacing or downsizing one is not a pure finish decision.
Exact wording
Under the California Residential Code, basements, habitable attics, the room a sleeping loft opens to, and every sleeping room must have not less than one operable emergency escape and rescue opening, opening directly into a public way or to a yard or court that opens to one — subject to the section's own exceptions, such as basements with ceilings lower than the stated height.
Residential Code § r319.1
Grade the lot to drain surface water away from the foundation walls.
The grade must fall at least 6 inches within the first 10 feet. Where lot lines, walls, slopes, or other physical barriers prevent that fall, build drains or that carry the water away from the structure.
On the job
Landscaping is also drainage: the finished yard either moves water away from the building or builds a defect against it.
Exact wording
Under the California Residential Code, lots must be graded to drain surface water away from foundation walls, with the grade falling not fewer than 6 inches within the first 10 feet — and where lot lines, walls, slopes, or other physical barriers prevent that fall, drains or swales must be constructed to ensure drainage away from the structure.
Residential Code § r401.3
Where people go wrong
Easy to mix up: Greenboard vs.
Which is which?
Easy to mix up: vs. grout
Which is which?
Sounds right: is a judgment call about which glass looks risky.
Where’s the catch?
Sounds right: "It's just a window swap"
Where’s the catch?
Sounds right: "Paint will hide a flaw in the wall underneath."
Where’s the catch?
Easy to mix up: vs.
Which is which?
Sounds right: Landscaping is the last trade, so it can't break anything
Where’s the catch?
Where to look it up
- Interior finishes — plaster, drywall, and the backers behind tile
- 2025 California Residential Code Chapter 7 (Wall Covering) — readable free in ICC's online viewer at codes.iccsafe.org
- Windows and glass — safety glazing locations, emergency escape openings
- 2025 California Residential Code Chapter 3 (Building Planning)
- Site drainage and finish grade around the building
- 2025 California Residential Code Chapter 4 (Foundations), the drainage section
- Painting, floor covering, and cabinetry practice — products, prep, installation
- The trade references the guide's own resource list names: Fundamentals of Building Construction, Olin's Construction Principles, Modern Carpentry
- The exact definition of a code term
- Chapter 2 of the Building and Residential Codes
- Finish work on buildings beyond the Residential Code's scope
- The 2025 California Building Code's own finish chapters, in the same ICC viewer
- The official statement of what this section covers
- CSLB's Study Guide for the General Building (B) Examination, section 4 — cslb.ca.gov
Glossary
Every term this guide defines, in one place. Each is also defined where it first appears.
- Backer board
- The cementitious or glass-mat panel used behind tile where water lives; the code lists where these materials are required.
- Casework
- The boxes: cabinets, built-ins, shelving carcasses.
- Corner bead
- The metal or plastic edge that gives an outside drywall corner a straight, durable line.
- Finish grade
- The final ground surface around the building — the one that must slope water away from the foundation.
- Grout
- The cement or epoxy filler packed into tile joints — it is not what holds the tile on, and it is not the waterproofing.
- Joint compound
- The "mud" — the paste that fills and fades drywall joints, corners, and fastener heads into one flat plane.
- Millwork
- Shop-made trim and shaped wood — casings, bases, crowns, stair parts.
- Primer
- The first coat — it seals and grips the substrate so the finish coats bond and cover evenly.
- Safety glazing
- Glass built to fail safely — tempered or laminated — required in the code's listed hazardous locations.
- Scribe
- Fitting a factory-straight edge to a wall that is not straight, by marking the wall's line onto the piece and shaving to it.
- Sheen
- How shiny a dried paint film is, from flat to gloss. Higher sheen wipes cleaner — and shows wall defects more.
- Substrate
- Whatever surface a finish goes onto — the drywall under paint, the slab under flooring. Finish failures are usually substrate failures.
- Swale
- A shallow graded channel that carries surface water away — the code's fallback where the yard cannot fall enough.
- Tempered glass
- Heat-treated glass that breaks into small blunt pieces instead of shards.
- Thinset
- Cement-based mortar that bonds tile to its backer.
- Underlayment (flooring)
- The layer between the subfloor and the finish flooring — smoothing, cushioning, or moisture control, depending on the product.
Keep going
- Practice questions for General Building (B) — Finish Trades is 20% of the exam.
- Job scenario: The Hall Bath Gut
- Also in Finish Trades: Finish Trades: The Rules the Exam Asks For
- Every number on one page — this guide’s figures alongside every other General Building (B) guide’s.
Finished reading?
When you miss a question on this topic, we'll suggest a job scenario where there is one, rather than text you've already read.