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Original Contractors License KIT
C-35 Lath and Plaster
Contractors License and Performance Bonds

C35 – Lathing and Plastering Contractor

(a) A lathing and plastering contractor coats surfaces with a mixture of sand, gypsum plaster, quick-lime or hydrated lime and water, or sand and cement and water, or a combination of such other materials that create a permanent surface coating, including coatings for the purpose of soundproofing and fireproofing. These coatings are applied with a plasterer's trowel or sprayed over any surface which offers a mechanical means for the support of such coating, and will adhere by suction. This contractor also installs lath (including metal studs) or any other material prepared or manufactured to provide a base or bond for such coating.

(b) A lathing and plastering contractor also applies and affixes wood and metal lath, or any other material prepared or manufactured to provide key or suction bases for the support of plaster coatings. This classification includes the channel work and metal studs for the support of metal or any other lathing material and for solid plaster partitions.

(c) Effective January 1, 1998, or as soon thereafter as administratively feasible, all C-26 licensees will be merged into the C-35 Lathing and Plastering classification. On and after January 1, 1998, no application for the C-26 classification will be accepted and no new C-26 Lathing licenses will be issued.

Authority cited: Sections 7008 and 7059, Reference: Sections 7058 and 7059 (Business and Professions Code)

Content of the Examination

The Lathing and Plastering (C-35) Examination is divided into four major sections. These sections are:

1. Estimation and Job Preparation (26%)

  • Plan and specification interpretation
  • Material calculations
  • Job site inspections

2. Lath Installation (27%)

  • Pre-lath inspections
  • Substrate preparations
  • Lathing materials and their applications
  • Methods for sealing penetrations
  • Code requirements for lath
  • Lath attachment methods and fastening devices

3. Plaster Application (27%)

  • Synthetics, architectural foam, and Exterior Foam Insulation Finish Systems (E.F.I.S.)
  • One, two, and three coat systems
  • Mixing ratios for scratch, brown, and finish coats
  • Application methods for scratch, brown, and finish coats
  • Factors that influence curing, cracking, and color variation

4. Safety (20%)

  • Work practices and conditions
  • Accident preventions
  • Cal/OSHA laws and regulations

*Percentages are approximate*

Test Site Policy
This is a closed-book examination. No reference materials may be used during the examination. All materials brought to the examination site must be left in an unmonitored area at your own risk.

Test Strategy
This is a multiple-choice examination with four choices per question. Some questions require mathematical computation. Examination questions are written to provide only one BEST answer and are NOT written as trick questions.

All correct answers have equal value and there are no score reductions for wrong answers. Therefore, all examination questions should be answered.

Ample time is provided to answer all examination questions, so be sure to read each question and its four choices completely and carefully before selecting the BEST possible answer to the question.

Sample Questions

The following questions are typical of the types of items that are on the examination. The correct answer is highlighted.

1. What should be done to the first coat in a two-coat work using gypsum plaster?

  1. It should be left true and smooth.
  2. It should be double-backed.
  3. It should be scored.
  4. It should have a higher proportion of aggregate than the second coat.

2. When using stucco finishes, which of the following is TRUE?

  1. It cannot be applied to smooth, dense surfaces.
  2. It may be used for both interior and exterior.
  3. It may be used as a base coat for Keene's.
  4. The finish coats generally require less aggregate than the base coats.

3. The MINIMUM thickness required for line wire for the backing on open wood frames is:

  1. No. 14 gage
  2. No. 16 gage
  3. No. 18 gage
  4. No. 24 gage

*All questions are written and reviewed by licensed contractors who are actively working in the field*

Cal\OSHA Construction Safety Orders.
California Code of Regulations, Title 8,
Industrial Relations, Division 1, Chapter 4, Subchapter 4.
Barclays Law Publishers,
P.O. Box 95767,
Chicago, IL 60694.
(800) 888-3600
FAX: (415) 732-8861.

California Building Code.
International Conference of Building Officials Headquarters,
5360 Workman Mill Road,
Whittier, CA 90601-2298.
(800) 284-4406.
FAX: (888) 329-4226

Effect of Mortar Composition on Wall Leakage: Masonry Mortar Technical Notes #5.
National Lime Association,
200 N. Glebe Road,
Arlington, VA 22203.
(703) 243-5463.
FAX: (703) 243-5489

Gypsum Construction Handbook, Second Edition.
U. S. Gypsum Corporation,
Department 193 Handbook,
125 S. Franklin,
Chicago, IL 60606.
(312) 606-4000
FAX: (312) 606-4093.

Plaster and Drywall Systems Manual.
Building News, Inc.,
1612 S. Clementine Street,
Anaheim, CA 92802.
(800) 873-6397
FAX: (714) 535-8078.

Portland Cement Plaster/Stucco Manual.
Portland Cement Association.
Publication Department,
P.O. Box 726,
Skokie, IL 60076.
(800) 868-6733
FAX: (847) 966-9666.

*Publisher information is current as of 07/03*

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