how to get your C-61 license for cooling towers installation in California

Wooden Tanks Contractor: C-61/D-53 License

Table of Contents

What is a C-61 / D-53 Wood Tanks Contractor?

“A wood tanks contractor erects or repairs elevated wooden storage tanks and related cooling towers. (Hot tubs are not included.)” – CSLB.GOV

The D-53 is the classification required in the state of California for all persons looking to contract for wooden tanks projects where the cost of labor and materials exceeds $500

A large wooden tank outside

C-61 Limited Specialty License

The C-61 Limited Specialty License is an umbrella term for all licenses that may fall under a more obscure category of construction work.

They cover specific areas of construction and construction-related tasks.

Often if your skillset or business is limited to one particular portion of trade work, you could obtain a C-61 limited specialty license to contract over $500 for your services legally.

Contractors specializing in wooden tanks often engage in the design, fabrication installation, and repair of various types of wooden tanks.

Wooden tanks can be used for a variety of different things including: 

  • Food and chemical processing 
  • Nickel extraction
  • Acid storage
  • Water storage
  • Beer and wine processing
  • Aluminum reduction
  • Fish Hatching
  • Brewary/Winery usage
  • Fire Protection
  • Rainwater collection and railroad water 

Commercial Cooling Tower Maintenance and Repair

Many contractors that hold the D-53 license offer Cooling tower services.

cooling tower installation and repair falls under the C-61 contractors license for wooden tanks

A contractor may engage in a variety of different activities including:

  • Design, fabrication and installation of above ground wood tanks
  • Repair and inspection of wooden tank insulation systems
  • Ensuring that wooden tank systems for fire protection are meeting adequate standards
  • Installing hoops that are polypropylene coated
  • Repairing pipe systems
  • Light carpentry
  • Operating heavy design machinery
  • Geological testing and site evaluation
  • Bidding, cost calculation and accounting

What is a subcontractor?

Wooden tanks contractors are typically sought out by breweries or manufacturing companies.

However,  in some cases, they may work as a sub to a General Engineering Contractor that could be completing a project that calls for specialized wooden tanks.

General Engineering Contractors oversee that the subcontractor has executed their duties in adherence to code and to the specific requests of a client. For a more in-depth look at the General Engineering Contractor license check out this article.


Logo of the CSLB, illustration features a paint brush, cement truck and hand saw with the letters CSLB above written in white

The Contractors State License Board (CSLB) is the governing body for all contractors in the state of California. Their sole responsibility is to protect the consumer public.

They ensure that anyone charging over $500 for construction services is qualified and registered with the state.  

CSLB Stings

The CSLB maintains a statewide task force that engages in sting operations to stop unlicensed construction activity.

Getting caught contracting without a license in California is punishable with fines up to $15,000 and 6 months in the county jail.

The CSLB issues the D-53 classification for wooden tanks in the state of California.

EPA Certification

When working in or around structures built before 1978, a wooden tanks contractor may need to contain lead paint if it is present.

Knowing the correct procedures required by the Environmental Protection Agency is critical for tradesmen working in a commercial setting.

Lead paint can travel miles through air, rest on soil, and enter air ducts causing potentially fatal respiratory damage. 

All tradesmen must be a source of information for their clients and community if they want referrals and repeat business.

For more information on adhering to EPA Standards when dealing with Lead Paint check out my article on lead safety.

Blue Print Reading Course

Two construction workers holding a blueprint. Wooden tanks contractors must know how to read blueprints

Being able to read and understand blueprints is a core skill for anyone working in or around a construction site.

Identifying the structural details and dimensions of a wooden tank before building or making alterations is critical. 

Construction blueprints communicate an array of information to builders.

Being comfortable with construction blueprints is an invaluable skill for all tradesmen, but especially for a wood tanks contractor who may be a part of a larger construction project. 

For a basic overview of Construction, blueprints are sure to check out our Online Blue Print Reading course.

Requirements for the D-53 Wooden Tanks License

To get a wooden tanks contractor license in California, you must prove a minimum of 4 years of journeyman level experience and pass a two-part state exam with the Contractor State License Board.

To qualify for an exam date you must meet the following requirements

  • Be at least 18 years of age
  • Have a valid Driver's License or USA Issued Identification
  • Have a Social Security or ITIN #
  • Not Currently be on probation or parole

You must also have:

  • 4 Years Journey Level Experience
  • A Qualifying Individual to sign off on your experience
  • A way to prove your experience if the state asks for documentation

What is a Journey level experience?

Journey level experience is gained working unsupervised full time for either a wooden tanks company, General A contractor, union, or directly under someone that holds the C-61/D-53 license.

Some Journeyman-level tradesmen have also completed apprenticeship programs. 

A Journeyman level tradesman can perform all the duties associated with his or her trade. The state will want to see 4 full-time years of experience within the last 10 years.

The years do not need to be consecutive, but they do need to be 4 years in total.

Signature of a Qualifying Individual

The following people may be used as Qualifying Individuals to sign off on your experience when applying for the wooden tanks license:

  • Licensed General Engineering Contractor
  • C-61/D-53 License Holder
  • Fellow Employee (within the last 10 years)
  • Former Supervisor (within the last 10 years)
  • Business Associate
  • Fellow Journeyman
  • Union Representative

Filling out the Contractor License Application

Your Qualifying Individual will also need to provide a brief but detailed description of your knowledge and skillset.

The way this description is written will be critical to whether or not your application is accepted. For example:

“Henry is a nice guy and very experienced” is not descriptive enough for the CSLB.

 The people reviewing your application will want to see:

“Henry has extensive experience designing, installing, and repairing wooden tanks for various types of use. He has engaged in continued maintenance, safety, and environmental compliance inspections” etc.

For a full list of the exact verbiage to increase the likelihood of your application being accepted. Check out my article on filling out the CSLB application.

The description written by your qualifying individual will need to include the core skills required for the wooden tanks license.

Proving your work experience

A large wooden tank in a factory

There is a possibility that the CSLB will ask you to submit documentation supporting your experience.

The CSLB gives you many ways to prove experience including Tax Returns, check stubs, receipts, invoices, and even contracts. Anything you have that can prove you have either run or worked for a company that offers ceiling services.

The state board receives thousands of applications every month.

There is a good chance they won’t request further documentation of your experience. However, if your application is chosen for review, you must be ready to submit something. 

Once your application has been accepted, you should receive your exam date within a matter of weeks.

Application Processing, Fees and Criminal History

The average application processing time is between 6-8 weeks.

Typically, you receive your exam date with another 3-4 weeks' notice before actually going to take the exam. 

This time frame can fluctuate based on many factors including:

  • Time of year (processing time slows down during the holidays)
  • Criminal History
  • Request to prove further documentation of experience
  • Mistakes on your application can also cause delays 

In total the entire process should take 90 days assuming none of the mentioned issues arise.

State Fees

The current state fees are:

1. $330 State Application Fee (one-time fee per application sent to the state board )

2. $200 License Activation Fee ( paid every two years )

You will also need to pay for live scan fingerprinting.

Construction Bonds 

everything you need to understand about Construction bonds and california contractor licenses

Upon passing the exam, the state board requires you to have a Contractor Bond number. 

A construction bond is a security deposit issued by a surety company. Bonds are designed to protect the consumer public against contractor default.

They act as protection mechanisms for clients from unethical or illegal actions performed by contractors. Bonds also ensure that subcontractors get paid for their work.

Furthermore, they ensure or that a contractor performs his duties as stated in a contract.

Construction bonds protect employees, suppliers, sub-contractors, or clients against a contractor's failure to abide by an agreement. For a deeper look at bonding and fees, check out this article.

Can you get a Contractors License with a Felony in California?

Having a criminal record in no way stops you from getting a wooden tanks contractor license. Thousands of tradesmen get licenses each year despite their criminal records.

Be honest on the application. Even if the felony or misdemeanor happened years ago and even if it was expunged. BE 100% HONEST ON THE APPLICATION, because the CSLB sees everything when you do live scan fingerprinting.

The CSLB handles criminal records on a case-by-case basis. Remember, the state board's responsibility is to protect the public.

Fraud, Embezzlement and Forgery

In my experience, the CSLB is primarily concerned with criminal charges dealing with fraud, embezzlement, forgery, and financial-related crimes.

If your conviction does not fall under these categories most likely, you will have no issues when applying for the C-61/D-53 wooden tanks license. Be prepared to submit any court documents or prove rehabilitation at the state’s request.

California requires you to divulge all criminal charges when applying for a state license even if they have been expunged.

What is on the Exam for the C-61/D-53 Wooden Tanks License?

Contractor licenses are broken down into four categories:

1) A-General Engineering

2) B-General Building

3) C-Specialty classes

4) C-61 / D-Limited Specialty classes

Each category of license except the D-Limited Specialty license class requires that you pass a TRADE exam. C-61 Classification licenses do not have trade portions.

You must only pass a LAW exam.

The exam is:

  • 115 Questions on Contractor LAW
  • 3 Hours to complete
  • Multiple choice, taken on a computer
  • Closed Book

The Law Examination is divided into eight major sections:

1. Business Organization (10%)

  •  Company organization
  •  Project organization

2. Business Finances (15%)

  • Cash management
  • Budget and planning
  • Taxes
  • Financial reporting

3. Employment Requirements (12%)

  • Employment regulations
  • Evaluation and record-keeping
  • Payroll

4. Bonds, Insurance, and Liens (10%)

  • Bonds
  • Workers’ compensation insurance
  • Liens and other remedies
  • Other insurance

5. Contract Requirements and Execution (23%)

  • Bidding
  • Cost control
  • Contracts
  • Payments

6. Licensing Requirements (8%)

  • Business license
  • Contractor’s license
  • Activity regulation

7. Safety (15%)

  • Training and reporting requirements
  • General safety
  • Hazardous/unknown materials

8. Public Works (7%)

  • Prevailing wage requirements
  • Bonding requirements
  • Insurance requirements

For more information about what is on the California Contractor LAW Exam, be sure to check out our blog post covering everything you need to know.

Recommended Resources

CSLB Test Locations

You will take the Contractor LAW exam on a computer at a state testing facility.

Currently, the CSLB testing locations are in Berkeley, Fresno, Norwalk, Oxnard, Sacramento, San Bernardino, San Diego, and San Jose.

The CSLB will assign you a testing center based on your location. The test is not available online. The CSLB allows you to bring a pre-approved translator with you.

The CSLB will grant you 18 months after your application is accepted to pass the examination. You must wait three weeks before retaking the state exam ($60 per retake).

Contractor License Study Guides and Practice Tests

A wooden triangular ruler and turquoise pencil laying on top of a white piece of paper

Getting your wooden tanks contractor license is a smooth process if you have the right information.

It can be confusing to see unfamiliar terms used to describe tools or job site practices.

The Contractor LAW exam covers a number of different topics. Questions are presented to you as if you are running a large-scale remodeling business with multiple employees.  

Contractor License Law

Understanding the difference between how it is every day on the job versus what the state expects of you is critical. Many contractors with decades of experience do not expect the questions they encounter on the exam.

Being prepared and knowing what to study is the most important thing you can do in ensuring your success on the contractor license exam.

Looking at some practice tests along with explanations for as little as 10 minutes a day is a small investment to make, but will increase your likelihood of success.

Construction Apprenticeships

If you don’t have the 4 years required journeyman level experience to obtain the C-61/D-53 license for wooden tanks, not to worry. Your journey begins here.

The construction industry offers an unlimited income opportunity.

Whether you are brand new or may have worked for a company offering wooden tanks services in the past, there are books, certification classes, and courses are available in most cities and online to get you up to speed. 

Usually, someone looking to get into the trade would find an apprenticeship. Getting hired by a contractor specializing in wooden tanks fabrication would be your next step.

After gaining the necessary 4 years of journeyman level experience, you would then be able to apply for the C-61/D-53 license.

For information on courses in your area or books to get you on the right path click here.