Opinion – The California State License Board (CSLB) Has a License Classification Problem For Deck Waterproofing

Multiple Classifications of Contractors Can Waterproof Decks, But Few Have to Pass a Written Proficiency Test

D-12 Synthetic Products Classification Doesn’t Require a Proficiency Test

Manufacturer’s Accept D-12 License’s to Become Authorized Applicators

If you want to be a general contractor, plumber, electrician, earth mover, well driller, roofer.. CSLB requires you to have 3 years certifiable experience in that trade, plus take a legal exam on CSLB and state contracting laws AND pass a 3 hour test on your proficiency in that trade. You have to prove you know what your doing before they give you a license to do it. There’s a risk to consumers from people who don’t know what their doing. CSLB goes out of their way to run sting operations on unlicensed contractors, running press releases and posting hidden videos of their stings.

However, if you want to be a contractor that installs waterproofing for foundation walls and decks, decks like say the balcony in Berkeley, you don’t need a license that has a test that proves you have some knowledge; you can obtain a D-12 Synthetic Products license like this author has. A D-12 Synthetic products contractor does not have to pass a written test of proficiency in the subject of waterproofing! You just need to apply for it if your licensed in another trade and add it to your classifications and start waterproofing decks and foundations as most of the deck manufacturer’s accept the D-12 classification to sell and install their products.

How do I know this? Because I have/had a D12 license classification with which I used it to waterproof decks and balconies. But I’m not the only one, there are many contractors out there waterproofing decks using a D12, as well as using a C8 (concrete) or a C33 painting license improperly apparently, and CSLB seems to have a lassez faire attitude about this issue.

Will CSLB change the licensing requirements for becoming a deck waterproofing contractor?

It’s time for it in my opinion. My further opinion is it’s time for manufacturer’s to stop accepting D12 licenses and require or implement training/education that ensure contractors know what they are doing. My experience as a consultant and former contractor is that nearly every case of a deck failure/leak/problem was a case of applicator or builder error, not the product or coating.

I learned the hard way not to accept conditions that others wanted me to accept so they could keep their project on track. Deck contractors MUST be able to inspect a deck and recognize any problems it might have before covering it or accepting the work. They must know how to properly flash a deck, install door pans, install waterproofing, test for moisture content before covering a deck, follow best building practices and insist any trades related to the deck as well. The training program I’ve personally developed over 8+ years that I use to train new deck waterproofing contractors demands a high degree of technical skill and willingness to exceed codes!

Below from CSLB is a email to me regarding my own situation. I’m using my experience in this opinion piece as it exemplifies the internal issues CSLB has on this. Note that CSLB Used to have a waterproofing classification but it went away. The D-64 Waterproofing also did not require a test either.

Context-a client had complained to CSLB about a deck failure. Part of the complaint was that I was out of class in doing the deck waterproofing using a D12 license. The part of the complaint about the deck failure went to arbitration where it was settled privately and is not subject to disclosure on my license. Part of the complaint did stay with CSLB, the part of license classification. So they went to work on that and I defended myself. Read through to see what CSLB says about their D12 problem.

“Hi Bill,

One of the complaint items provided by Mr X was that your company was operating out of class for the work performed. The arbitration does not address classification as part of its process, so I needed to address this issue separately. As you know, your company holds a D12 (Synthetic Products) classification. This classification is defined as follows:

A synthetic products contractor installs:

  • (a) Synthetic counter tops and wall coverings; fiberglass, plastic, vinyl and epoxy products; plastic tile board and decorative art work; and synthetic turf.
  • (b) Bathtub and enamel refinishing, resin and epoxy application, and synthetic caulking and sealants.
  • (c) Reservoir liners, vinyl swimming pool relining, pier piling wrap, and rodent guards.
  • (d) PVC piping systems for irrigation and drainage; subsurface irrigation drip systems.

As you can see from the definition, there is a very limited scope of work for this classification. For Mr. X’s project, as well as the other services listed on your website, the D12 classification is not appropriate. A General Contractor’s license (B) would best suit your business as it would safely encompass all unrelated trades. Short of a B license, there are specific trade classifications that more accurately apply to your services for concrete overlays, deck coatings, etc. You can review the classifications by clicking HERE.

For Mr. X’s case specifically, the work (waterproofing, flashing) performed would have required either a B license or a C39 Roofing classification. The definition for the C39:

A roofing contractor installs products and repairs surfaces that seal, waterproof and weatherproof structures. This work is performed to prevent water or its derivatives, compounds or solids from penetrating such protection and gaining access to material or space beyond. In the course of this work, the contractor examines and/or prepares surfaces and uses the following material: asphaltum, pitch, tar, felt, glass fabric, urethane foam, metal roofing systems, flax, shakes, shingles, roof tile, slate or any other roofing, waterproofing, weatherproofing or membrane material(s) or a combination thereof.

I would recommend reviewing the classifications and either adjust the work you perform to fit the D12 classification or apply for more suitable classifications. The General Contractor (B) classification would be all-inclusive, but you can certainly piece together classifications to fit the work you perform.

Since we don’t have a history of complaint issues with you, I will simply send you a warning letter for this issue. If you have any questions, let me know.

Shaun Baland

Investigator, Sacramento IC CSLB Enforcement


I was stunned as I had applied to CSLB and stated on my application what I was doing-installing flashings, deck waterproofing and replacing plywood substrate! So I replied to CSLB with this email below

Hi Shaun, Thank you for the information.

When I began the process of becoming a licensed deck waterproofing applicator, I approached my main distributor, Hill Brothers Chemical Company and asked them what licenses they accept to be a Desert Brand applicator. They told me D-12, C,31 or a D8.
I applied for the D-12 and when the app process was proceeding, the only thing I was told was to change my name from Central Coast Waterproofing to Central Coast Synthetic Waterproofing.

730303 SB Surfacing also has a D-64 Waterproofing classification?

If you run a list of D-12 licenses, and look them up on the web, I think you will find a lot of them are running waterproofing/concrete coating companies…I’m not saying that’s an excuse, but it is what CSLB has been issuing to a lot of waterproofing companies.
Can I argue that they all need to reclassify if I have to? 😉
If I get a roofers classification my workers comp premium costs will put me out of business as we won’t be competitive with our competition paying a painters wc classification (that’s the class my WC carrier put me under…) My main distributor doesn’t even accept B licenses as they want specialty contractors doing their decking systems…
As to the scope of work, we installed sheet metal to terminate our coating to as required by the manufacturer. We don’t do any other sheet metal work, ie AC or HVAC…just installing a metal termination point for our coatings I installed the drain integrated with the sheet metal flashing but did not hook it to any plumbing connections.
I’m more than willing to switch classifications and work with CSLB to be compliant; I just can’t afford to not work while any re-classification is going on…
What can we do?
Thanks for your help Shaun!
Bill Leys
I got this reply back a little later on…
Hi Bill,

I believe you are being honest about the situation. I spoke to my manager about the situation and asked him to look into this further. Somewhere there is confusion about the acceptable classifications for this type of work, so we need to get a consistent opinion on this. Once I hear something, I’ll let you know.



I then get this back from an inquiry-

Hi Bill,

We are looking into the issue currently. Until you hear otherwise, you are fine operating as usual. Obviously this isn’t an isolated issue as you have provided several other examples of similar businesses with the same classification you have. I hope to have the issue clarified as soon as possible. Our goal is not to shut you down or cost you business, simply to make sure you are in compliance with the proper classification. This very well may just have been miscommunication or misunderstanding at the time of your application. I’ll let you know as soon as I hear anything.

Then I got this

Hi Bill,

Your D-12 issue is being bounced around like crazy, still waiting for a final decision.

Finally this-

Hi Bill,

OK, so it seems the consensus is that waterproofing work falls under the C39 Roofing classification. It is possible that a specialty classification for waterproofing becomes available at some point, but as of right now the C39 will be the classification that covers all waterproofing services. There are several classifications that would encompass different (non-waterpoofing) portions of the services you offer, but it appears that adding the roofing classification to your existing synthetic products classifications would cover you well(no pun intended).

If you disagree with the determination, you can request a formal review and determination from CSLB. You would just need to email classifications@cslb.ca.gov to present your information and request the opinion.

Let me know if you have any questions-


So I then asked this of CSLB…Incidentally an ex employee of mine was applying for a license and did receive a D12 license while this was going on.

Hi Shaun,

Ok, so what is CSLB doing? Making just me get a C39 or is every D-12 going to have to get a C39 as well?
What about the C-33 painting class which mentions waterproofing?

To Which I Got This Answer

I don’t know how or if they are notifying other businesses who will be in similar situations. Eventually, each business performing work that requires a different or additional classification has to amend their license. I have forwarded the information along in regards to your specific situation as well as the similar businesses you provided me previously. I don’t know how CSLB will ensure compliance in regards to the waterproofing contractors.

The C33 is one of the classifications that may apply to some (or possibly most) waterproofing projects, but not all. If the surface being waterproofed is considered roofing (or a rooftop deck), then C39 would definitely cover the work while the C33 may or may not. It would be determined on a case-by-case basis. If you don’t plan on waterproofing roofs or rooftop decks, then the C33 may be appropriate as well.


I replied with more questions…

Hi Shaun,

I assume then I’ll receive a letter in the mail telling me all this…how do I qualify? By taking the roofing test or do I get a pass for this one?
Do I keep the D-12 and that’s for epoxy flooring work?
So are you saying that from now on that applications for a D-12 get rejected and they have to submit for a C-39 classification for deck work? I’m not objecting to the classification as I guess yes we are waterproofing roofs that are simply walkable decks too. No argument.
I just want the competition out there to all have to do the same thing. Haven’t talked to my insurance guy yet top get a quote on workers comp but all the roofers I know all roll their eyes when i ask about w/c costs.
What about a B license? Could I do roof decks as a B? One of my main competitors here is a B.
Thanks for the help,
Shaun at CSLB replied-
Hi Bill,

Yes, B Contractors are all-inclusive and can certainly be used for the type of work you are doing. You are supposed to be doing at least two unrelated trades if only using a B classification, but that is pretty easy to justify unless you are simply rolling some waterproof material on a surface with zero other work being done. Worker’s comp costs for the B license may be cheaper than the roofing classification also.

I am leaving your case alone since it was referred to arbitration. If the classification issue bounces back to me then I may have to issue a warning letter, but for now I’m assuming it’s done. Consider your classification options, and then you’d just need to apply to add a classification to your existing license. There are costs, tests, etc depending on which classification you decide to add. I understand wanting to make sure the competition is held to the same requirements. BOMBSHELL HERE- I don’t know if CSLB will be sending out info on this to affected businesses, or if they’ll just address them individually as renewals come up. If you can, send me a a handful of D12’s doing your type of work. I can forward them along to the Classifications Unit. Perhaps they can do something to get this info out to everyone before it becomes a bigger issue.



PS- Thank you for your patience with this whole thing. I know it must be frustrating!

So we’re told that CSLB is just going to meander along…a call to a couple D12 license contractors I know reveals that they’ve been renewing their licenses without any problem from the renewals department. R Brothers has a D12 license, but not a roofing license. Their B license may allow them to do waterproofing, but it really shouldn’t. The C33 probably wouldn’t apply since a waterproof balcony would be construed as a roof.

Opinion-It’s time CSLB creates a deck and below grade waterproofing license classification that requires a written test of proficiency.

But this leaves the unanswered questions-what to do about all the C33’s, D12’s and D8’s doing waterproofing work apparently improperly? It’s a mess CSLB has created and they certainly seem to have a classification problem for deck waterproofing contractors.

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