What Is a C-2 Insulation & Acoustical Contractor?

The C-2 License for Insulation and Acoustical Contractors covers a few different job titles include:
- Soundproofing Contractors
- Ceiling Contractors
- Insulation Specialists
- Home Insulation Contractors
These job titles are essentially interchange and all fall under the C-2 license for insulation and acoustical contractors.
Online Practice Exams and Study Guides Package
Duties of an Insulation Contractor
Insulation contractors engage in a wide variety of duties including:
- Installing grid ceiling systems, insulated pipes and ducts, semi-grid and thermal insulation boards
- Installing batt, rigid board, and radiant barrier applications
- Sealing buildings to stop air filtration
- Soundproofing
- Weatherstripping
- Erecting scaffolding, ladders, and plants
- Maintaining a safe job site
- Estimation, bidding, accounting, and preparing invoices
Getting the C-2 license will require that you have knowledge of all aspects of the insulation and acoustical trade.
A C-2 Insulation & Acoustical contractor legally is not allowed to bid on a project that falls outside of the spectrum of general insulation, acoustical construction, maintenance, or repair work.
C-2 License Requirements
To qualify for an exam date for the C-2 license you must meet the following requirements:
- 18 Years of Age
- Valid Drivers License or USA Issued Identification
- Social Security OR ITIN Number
- Cannot Currently be on Probation or Parole
You must also have:
- 4 Years of Journeyman Level Experience
- Signature from a Certifier (someone who can vouch for your experience)
- Proof of experience if the state board requests
What is Journeyman Level Experience?
Journeyman-level experience means that you have worked unsupervised full-time for a construction company, a contractor with the C-2 License, or a union.
The CSLB will want to see four full-time years of experience over the last ten years. The years do not need to be consecutive, but they do need to be four years in total.
Signature Of A Qualifying Individual
A qualifying individual is someone other than yourself who can confirm your experience.
This person can be either a:
- Licensed General Contractor
- Licensed Insulation and Acoustical Contractor (C-2 License)
- Fellow or Former Employee (within the last 10 years)
- Foreman or Supervisor
- Business Associate
- Fellow Journeyman
Whoever you choose must include their information and a brief description of your experience.
The main areas of expertise an Insulation Contractor needs to have experience in are:
- Installing Grid Ceiling Systems
- Erecting Scaffolds and Ladders
- Installing Sound Control Systems, pipes, and ductwork
- Sealing Buildings to stop air infiltration
- Insulating attics
- Weatherstripping
- Foil Reinforced Insulation
- Applied Polyurethane Insulation
- Insulated Pipes
- Rolled Insulation Batts
- Sprayed Foam
Filling out the C-2 License Application
When you are filling out your application to the CSLB, you must remember that the description your qualifying individual writes for you has to go into detail about your specific skill set.
Instead of just saying: “John has insulated homes…”
The CSLB will want to see: “John has installed grid ceiling systems, sealed buildings to stop air infiltration, installed weather stripping, soundproofed recording studios, etc.
Insulation Subcontractor
Insulation contractors that hold the C-2 license typically work directly with clients.
However, if they are working in a traditional construction setting they would function as a subcontractor under a company or individual who holds the General B license.

- Music and Entertainment Industry Clients
- Soundproofing
- Residential and Commercial Setting
- Optimizing Control Systems
- Knowledge of Acoustics
- Creating Sonically Balanced Rooms
- Insulation and Acoustical Services
A General Contractor is in charge of the job from start to finish and must make sure that the insulation and acoustical portion of the project are completed to the specific requests of the client.
Proving your work experience for the C-2 License
You must be prepared to submit documentation supporting the experience you claim to have.
The Contractors State License Board gives you many ways to prove your experience including:
- Tax Returns
- Check Stubs
- Contracts
- Material Order Invoices or Receipts
The CSLB receives thousands of applications per month.
So there is a good chance they won’t document your experience.
However, if you are one of the applicants that get reviewed you will need to be ready to submit something.
The CSLB does not accept pictures of projects.
Application Processing, Fees, and Criminal History
The time it takes to get your application processed and assigned a test date fluctuates throughout the year.
Typically you can expect:
- 6-8 Week Application Processing Time
- 3-4 Week wait for an Exam date
I have seen some situations where applicants got their test date sooner and somewhere they got their test date much later.
The most common reasons your application would get held up are:
- Time of year (processing time slows down during the holidays)
- Criminal History
- Proving Experience
- Mistakes on your application
Licensing Fees
- State Application Fee
- License Activation Fee
- Fingerprinting
- Bond Fee (What is a Construction Bond?)
See video below for the most up-to-date fees!
Can you get a contractor's license with a Felony In California?

Having a criminal record in no way stops you from getting a C-2 License.
See the CSLB statement below:
Just because you have been convicted of a crime does not automatically mean your application will be denied. CSLB's Criminal Background Unit (CBU) reviews all criminal convictions to determine if the crime is substantially related to the duties, qualifications, and/or functions of a contractor. Since no two conviction records are the same, they are reviewed on a case-by-case basis. The criteria used by CSLB include whether the crime shows the present or potential unfitness of an applicant or licensee to perform the functions authorized by the license in a manner consistent with the public health, safety, or welfare. In addition, CSLB reviews and considers any evidence of rehabilitation submitted by the applicant or licensee. Please see the above link to the California Code of Regulations sections 868 and 869 for more specific information on the criteria for determining substantial relationship and rehabilitation.
Read more from the CSLB regarding background checks
BE 100% HONEST ON THE APPLICATION, because they will see everything anyway when you do fingerprinting.
The CSLB handles criminal records on a case-by-case basis.
Remember, their responsibility is to protect the public. In my experience, they are primarily concerned with criminal charges associated with:
- Fraud
- Embezzlement
- Forgery
In the state of California, you are required to divulge any criminal charges when applying for any state license even if they have been expunged.
You will need to be prepared to submit anything they ask for regarding your criminal history.
Contractor Exam: C2 License
Contractor licenses are broken down into four categories:
1) A-General Engineering (LAW + TRADE )
2) B-General Building (LAW + TRADE)
3) C-Specialty Classes (LAW + TRADE)
4) C-61/D- Limited Specialty (LAW TEST ONLY)
The C-2 License Exam consists of two parts:
- 115 Questions of Contractor LAW
- 115 Questions on Insulation & Acoustical
- 3 Hours To Complete Each Portion
- Closed Book Exam
The Insulation and Acoustical (C-2 license) Examination is divided into four major sections:
1. Planning and Estimation (29%)
- Review Plans and Specifications
- Evaluate Job Sites
- Estimate Material Quantities and Costs
2. Acoustical (16%)
- Ceiling Grids
- Acoustical Tile and Wall Panels
- Seismic Requirements
3. Insulation (28%)
- Site Preparation and Blowin-in Applications
- Insulation Preparation
- Insulation Installation
4. Safety (27%)
- Personnel safety
- Job site safety
CSLB Test Locations

The Contractors State License Board has testing centers all over the state of California. You will be assigned a testing center based on your zip code.
- You have 18 months after your application is accepted to pass both examinations
- You must wait 3 weeks to re-take the exam. $100 Per Re-take
What is on the Law & Business portion of the Insulation & Acoustical Contractor License exam?
California Contractor License Exam Prep

- The questions you will see on the exam may use outdated terms
- Processes may be completely different from how things are done on the job site
- You will see questions about things you may have never done before
- Questions will be presented to you as if you are running a large-scale construction business with several employees and jobs happening all at once.
- Know all aspects of your trade
Contractor License Practice Tests
Construction professionals from various backgrounds, trades, and experience levels get licensed in California each year.
In my experience, most are startled by how different the subject matter on the state exam is from their years of first-hand experience.
Be as prepared as you possibly can.
Studying just 15 minutes a day consistently can dramatically increase your chances of passing the test on your first try.
Focus on and study ONLY the information that you need to pass the C-2 License exam.
Construction Apprenticeships

If you don’t have the four years required journeyman-level experience to obtain a C-2 License, not to worry.
Your journey begins here.
Construction is a trillion-dollar industry and highly skilled tradesmen are always in demand.
Whether you are completely new or have some home insulation experience already, there are resources available to you.
Generally, someone looking to become an insulation contractor would want to look into an apprenticeship program.
For a detailed explanation of this process, check out my article: Apprentice vs Journeyman.
Blueprint Reading Course

Like most construction trades, knowing how to read blueprints is very important.
Correctly identifying elevations, ceiling, and wall plans to complete the insulation and temperature portion of their duties effectively.
Insulation contractors that aspire to hold a General Contractor License in the future will surely want to make sure their blueprint reading skills are up to par.
Check out this Blue Print Reading Course for a basic introduction to the concepts you will want to know about.
EPA Certification

Understanding how to safely contain lead-based paint when altering structures built before 1978 is required by the Environmental Protection Agency.
The most profitable contractors are ones that position themselves as the experts and are the most knowledgeable and helpful to their clients.
Becoming EPA Certified is a requirement for insulation contractors and can be completed in a one-day, 8-hour course.
Staying EPA compliant is not only important to the survival of your business but also to the safety of your customers.
For a complete guide on how to get the EPA Certification, check out this article.
Mold Certification
Working in a residential setting as an insulation & acoustical contractor, you may encounter mold.
Mold can create considerable problems for homeowners looking to protect the health of their families as well as the value of their property.
At some point, every property owner will require Mold remediation services.
Mold caused by water damage can create long-term problems for any structure.
Getting a Mold Remediation Certification positions you to offer a needed service to a large customer demographic.
This article will detail everything you need to know about:
- Mold
- Health risks
- Certifications
- State laws
- Starting a Mold Remediation Business
Conclusion
Getting the C-2 License can be a huge step up in your career within the insulation industry! Whether you are trying to open your own company or become an RMO, there are several options.
The key is to take action and follow these steps from beginning to end.
If you have found this article helpful feel free to drop a comment below and be sure to check back for updates!