CSLB General Building (B) Trade Practice Test
Frequently asked questions
How many CSLB Landscaping (C-27) Trade practice questions are here?+
A full bank of original CSLB Landscaping (C-27) Trade practice questions across the official content areas, weighted like the real exam, with explanations. Free, no signup.
What is the CSLB Landscaping (C-27) Trade exam like?+
About 100 questions, 210 minutes, and you need 72% to pass. Practice by topic here, then take the full timed mock exam to gauge readiness.
Are these the real exam questions?+
No. Every question is 100% original, written from public primary sources with explanations. We never copy real exam questions or paid prep material.
Can I study in Chinese or Spanish?+
PrepPass practice is in English, 中文 and Español. The official exam is in English — switch the question language to English any time to rehearse the exact terminology you'll see on test day.
Sample practice questions
A few real questions from this free bank, with full explanations. Use the practice tool above for the whole set.
- 1. Irrigation
A rotor sprinkler head throwing water 30 feet is BEST described as which type of irrigation component?
- a.A drip emitter for point-source watering
- b.A gear-driven rotor for large turf areas
- c.A micro-spray for shrub beds
- d.A bubbler for tree wells
Answer: b
Explanation: Gear-driven rotors rotate a single stream back and forth and are designed for large open turf areas because of their long throw radius, typically 25 to 50 feet. Drip emitters, micro-sprays, and bubblers all deliver water at much shorter ranges for beds, shrubs, or trees.
- 2. Irrigation
A drip emitter rated at 1 GPH means it delivers approximately how much water per hour?
- a.1 gallon per hour
- b.1 gallon per minute
- c.60 gallons per hour
- d.1 quart per day
Answer: a
Explanation: GPH stands for gallons per hour, so a 1 GPH emitter releases one gallon over a full hour of operation. Drip systems are rated in gallons per hour because they apply water slowly and precisely at the root zone. This low, slow application reduces runoff and evaporation.
- 3. Irrigation
Subsurface drip irrigation is especially useful in which situation?
- a.Watering a steep concrete slope
- b.On slopes and narrow strips where overspray and runoff must be avoided
- c.Filling a decorative pond
- d.Cooling a patio surface
Answer: b
Explanation: Subsurface drip places emitter tubing below the soil surface, delivering water directly to roots with virtually no overspray or runoff. This makes it well suited for slopes and narrow strips where spray irrigation would waste water on pavement. It also reduces evaporation and weed germination at the surface.
- 4. Planting & Soil
Applying a 3-inch layer of organic mulch around plants primarily provides what benefits?
- a.Raises soil pH sharply
- b.Eliminates all irrigation needs
- c.Conserves moisture, moderates soil temperature, and suppresses weeds
- d.Increases soil compaction
Answer: c
Explanation: A layer of organic mulch reduces evaporation, keeps soil temperatures more stable, and blocks light that weed seeds need to germinate. As it decomposes it also adds organic matter to the soil. Mulch is one of the most cost-effective water-saving practices in landscaping.
- 5. Planting & Soil
Compost is added to soil primarily to do what?
- a.Raise pH to strongly alkaline levels
- b.Improve soil structure, add organic matter, and support microbial life
- c.Serve as the sole source of all nutrients permanently
- d.Compact the soil
Answer: b
Explanation: Compost improves soil structure, increases water and nutrient holding capacity, and feeds beneficial soil microorganisms. While it adds some nutrients, its main value is as an organic amendment that improves overall soil health. It benefits both sandy and clay soils.
- 6. Hardscape & Grading
Aggregate base under hardscape is best compacted in what manner?
- a.In one thick lift with no compaction
- b.Only after the pavers are placed
- c.In thin lifts (layers), each compacted before the next
- d.By soaking it with water only
Answer: c
Explanation: Base material should be placed and compacted in thin lifts, commonly around 3 to 4 inches, so the compactor can achieve full density throughout. Compacting one thick lift leaves the lower portion loose, causing later settlement. Layered compaction produces a stable, uniform base.
- 7. Hardscape & Grading
Compaction of subgrade soil before hardscape is measured against what standard reference?
- a.The color of the soil
- b.The soil's pH
- c.The number of passes only
- d.A percentage of maximum dry density (for example, 90 to 95 percent)
Answer: d
Explanation: Compaction is specified as a percentage of a soil's maximum dry density determined by a laboratory Proctor test, commonly 90 to 95 percent for hardscape subgrade. Field testing verifies the soil reaches the required density. Adequate compaction prevents future settlement under pavement.
- 8. Planning & Estimating
To find the area of a circular planting bed with a 20-foot diameter, which calculation is correct?
- a.20 x 20
- b.3.14 x 20
- c.2 x 3.14 x 10
- d.3.14 x 10 x 10 (about 314 square feet)
Answer: d
Explanation: Circle area equals pi times the radius squared, and the radius is half the diameter, so 10 feet. Thus 3.14 x 10 x 10 equals about 314 square feet. Using diameter instead of radius is a common estimating error.
- 9. Safety
Before any excavation or trenching in California, the law requires a contractor to do what?
- a.Only notify the property owner
- b.Wait 30 days
- c.Contact the regional notification center (DigAlert/811) to mark underground utilities
- d.Dig a test hole first without notice
Answer: c
Explanation: California Government Code section 4216 requires excavators to contact the regional one-call center, DigAlert (811), at least two working days before digging so utility owners can mark their buried lines. This prevents striking gas, electric, and other utilities. Failing to call can cause deadly accidents and legal liability.
Source: Gov Code §4216 (DigAlert)
- 10. Safety
When mixing and applying pesticides, the label directions are legally significant because what?
- a.They are only suggestions
- b.They can be ignored by licensed applicators
- c.They apply only to homeowners
- d.The label is the law and must be followed exactly
Answer: d
Explanation: Under pesticide regulations, the product label is a legal document, and using a pesticide in a manner inconsistent with its labeling is a violation. The label specifies rates, sites, PPE, and restrictions that must be followed exactly. This protects applicators, the public, and the environment.