(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
Job site inspections
2. Lath Installation (27%)
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
Cal/OSHA laws and regulations
*Percentages are approximate*
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?
It should be left true and smooth.
It should be double-backed.
It should be scored.
It should have a higher proportion of aggregate than the second coat.
2. When using stucco finishes, which of the following is TRUE?
It cannot be applied to smooth, dense surfaces.
It may be used for both interior and exterior.
It may be used as a base coat for Keene's.
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:
No. 14 gage
No. 16 gage
No. 18 gage
No. 24 gage
*All questions are written and reviewed by licensed contractors who are actively working in the field*