- The Short Answer: What a CSDR Is
- Who Issues the Credential
- CSDR, CSDS and CRSD: Clearing Up the Names
- What a Remediator Is Expected to Know
- How the Exam Works
- Who Qualifies to Sit for It
- Fees, Renewal and Lifecycle
- Where the Credential Fits in the Industry
- The Reference Library Behind the Exam
- A Domain-Ordered Preparation Path
- Frequently Asked Questions
- A CSDR is a Council-certified Structural Drying Remediator, a credential issued by the American Council for Accredited Certification (ACAC).
- The exam is 120 multiple-choice questions in three hours, closed book, with a 75% passing score.
- Initial cost is $500 ($100 exam plus $400 certification); renewal is $400 every two years.
- Eligibility requires either a science-related degree plus one year, or a diploma/GED plus two years, of documented structural drying experience.
The Short Answer: What a CSDR Is
A CSDR is a Council-certified Structural Drying Remediator. It is a professional certification for people who plan and carry out the drying of water-damaged structures using scientific principles rather than guesswork. The credential is issued by the American Council for Accredited Certification (ACAC), and it signals that a practitioner has documented field experience and has passed a closed-book examination covering psychrometry, drying strategy, equipment, safety, regulations and project execution.
If you have seen this acronym elsewhere, be careful. Several unrelated credentials abbreviate to the same letters. On this site, and throughout this article, CSDR refers only to the ACAC structural drying credential. When you search for information, qualifying the term with "ACAC" or with the full credential name will keep you out of the wrong results. For a quick companion read on the abbreviation itself, see What Does CSDR Stand For?
Who Issues the Credential
The governing and certifying body is the American Council for Accredited Certification. ACAC publishes candidate handbooks, runs the application and review process, sets the fee schedule, and administers recertification. The examination itself is delivered through Kryterion, Inc., either at authorized testing centers or through secure online video proctoring.
The CSDR is also accredited through the Council of Engineering and Scientific Specialty Boards (CESB) at the engineering-technician level. That accreditation matters because it indicates the certification program itself has been reviewed against an external standard, rather than simply being self-declared by the issuer.
CSDR, CSDS and CRSD: Clearing Up the Names
The structural drying program has more than one credential, and the similar abbreviations cause real confusion. The official program page and the handbook's designation-use section establish the Remediator name for the CSDR. The Supervisor-level credential is CSDS, not CSDR.
There is a wrinkle worth knowing about. The CSDR section of the published candidate handbook contains some wording that says "Supervisor" in its preamble and "CSDS" in its skills introduction and final statement. That is a quirk of the source document. It does not mean the CSDR exam is the CSDS exam, and it does not change the CSDR's own eligibility rules. When you read the handbook, keep the credential names straight in your own notes and follow the CSDR section's requirements for the CSDR path.
| Abbreviation | What it refers to here | Practical note |
|---|---|---|
| CSDR | Council-certified Structural Drying Remediator (ACAC) | The credential this article covers |
| CSDS | Structural Drying Supervisor (ACAC) | A separate credential; do not substitute it for CSDR |
| CRSD | Not the CSDR | A different abbreviation; do not use it interchangeably |
If you are weighing the credential against other structural drying options, search with the full name and compare programs on their own published requirements rather than assuming the letters line up.
What a Remediator Is Expected to Know
The CSDR section of the ACAC handbook lists seven competency statements. These are best treated as the official statement of what a certificant must understand, not as seven independently weighted exam domains. ACAC's separate examination-content chart could not be retrieved for this article, so no percentage weights are asserted here. For a deeper walk through each area, see the complete guide to the seven CSDR content areas.
Domain 1: The ACAC Code of Conduct
A certificant understands and abides by the ACAC Code of Conduct. The Code of Conduct is required reading, and candidates should treat it as examinable rather than as a formality.
Domain 2: Guidelines, Regulations and Standards
A certificant understands guidelines, regulations and standards relevant to the structural drying industry. Published supporting topics include:
- The OSHA general duty clause
- Personal protective equipment (PPE)
- Emergency and fire plans
- Confined spaces and hazardous atmospheres or materials
- Walking and working surfaces, ladders, scaffolding and warnings
Domain 3: Principles, Strategies and Equipment
A certificant applies knowledge of principles, strategies and equipment to the design and execution of structural drying projects. This is the umbrella statement that ties science to hands-on practice.
Domain 4: Psychrometry and Hygroscopic Materials
The certificant understands the basic principles of psychrometry and hygroscopic materials. Published topics include:
- Temperature, humidity, vapor pressure and heat
- Psychrometric charts
- Water phases
- Wood, equilibrium moisture content and cementitious materials
Domain 5: Designing Effective Drying Strategies
The certificant correctly applies scientific principles in the design of effective drying strategies, including Dalton's evaporation formula and the logic of open, closed and combination drying systems.
Domain 6: Selecting and Operating Equipment
The certificant selects and operates appropriate drying equipment, including:
- Water-class-appropriate equipment
- Air movers and dehumidifiers
- Portable heating and cooling
- HVAC and ductwork considerations
- Dehumidification formulas
Domain 7: Phases of a Structural Drying Project
The handbook's seventh statement concerns correctly designing and executing the phases of a project, including project planning, documentation, drying procedures, HVAC and microbial considerations, and drying validation. Note that the source wording for this line says "CSDS" instead of "CSDR," which is the handbook inconsistency described above; it is preserved here as written in the CSDR section, not imported from the separate Supervisor section.
How the Exam Works
The CSDR examination is built around recall plus application. Candidates are expected to interpret conditions, choose a drying approach, and justify it with the underlying physics rather than simply memorize definitions.
| Feature | Detail |
|---|---|
| Number of questions | 120 multiple-choice |
| Time allowed | Three hours (the written exam duration) |
| Answer choices | At least four per question |
| Reference materials | Closed book |
| Passing score | 75%, set using the Modified Angoff Method |
| Question and answer order | Randomized |
| Results | Immediate electronic results plus an emailed result |
| Delivery | Kryterion, Inc. testing centers or secure online video proctoring |
The Modified Angoff Method means the passing standard is set by subject-matter judgment about how a minimally qualified practitioner should perform, rather than by grading on a curve. For a plain-language breakdown, read CSDR Passing Score 2026: Exactly What You Need to Pass, and for a realistic sense of difficulty, see How Hard Is the CSDR Exam?
One honest caveat on statistics: ACAC's published Accredited Certification Activity record for December 31, 2025 lists one current CSDR certification and no numerical 2025 CSDR pass ratio. A dash in that table should not be read as a zero-percent pass rate. The data are simply too thin to support a pass-rate claim, which is discussed further in CSDR Pass Rate 2026: What the Data Shows.
Who Qualifies to Sit for It
Unlike many technical exams that you can book on a whim, the CSDR is gated by documented experience. There are two routes:
- Education-plus-experience route: a qualifying two-year postsecondary degree, or an equivalent 15 credit hours, in engineering, science, architecture, industrial hygiene or a related scientific field, plus at least one documented year conducting structural drying projects.
- Experience-heavy route: a high-school diploma or GED plus at least two documented years of structural drying experience.
Regardless of route, the application requires four project sheets, educational records when applicable, employer or experience verification, application review, and certification-board approval. Preparatory training is not mandatory, so you do not have to buy a course to qualify, though independent preparation can still help you cover the reference library. The full qualification picture is laid out in CSDR Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Fees, Renewal and Lifecycle
| Item | Cost (USD) |
|---|---|
| Examination fee | $100 |
| Certification fee | $400 |
| Initial total | $500 |
| Retake | $100 |
| Renewal | $400 |
The certification lasts two years. Current renewal procedures call for 40 recertification credits: 10 for continued field activity plus 30 professional-development hours, along with audit records and the required current photo. Plan for renewal from the day you are certified, because the credits accumulate over the full two-year window and are easier to log as you go. A fuller cost walk-through is in CSDR Certification Cost 2026: Complete Pricing Breakdown.
Where the Credential Fits in the Industry
A CSDR is aimed at people whose daily work involves water-damaged structures: restoration project managers and lead technicians, field supervisors, drying specialists working on residential and commercial losses, and professionals who write or review drying plans and validation records. The credential is most useful where an employer, carrier or client values documented, standards-based drying decisions.
It is worth being straightforward about the limits of what can be said. The installed base of certificants recorded in ACAC's dated activity report is very small, and that number is not a measure of keyword volume, revenue potential or earning power. There is no published CSDR pay premium to quote, and any salary claim for this specific credential would be speculation. If you are trying to decide whether the investment makes sense for your situation, the more useful frame is your current structural drying role, your employer's expectations and your own career direction. Two companion pieces take that up: Is the CSDR Certification Worth It? and CSDR Salary Guide 2026.
For a role-oriented view of the kinds of positions this credential might support, see CSDR Jobs.
The Reference Library Behind the Exam
The CSDR study guide organizes preparation around three reference sources. These are preparation categories, not a three-domain exam blueprint and not an exhaustive statement of exam coverage.
- ANSI/IICRC S500-2021: the fifth edition of the standard for professional water damage restoration. The study guide specifies the entire S500 text.
- Larsen et al., Leadership in Restorative Drying, fourth edition (2014): selected reading locations are specified.
- NIOSH, Respirator Selection Logic (2004): selected reading locations are specified.
The ACAC Code of Conduct is also required reading. These are reference editions, not a numbered 2026 exam version. The study guide specifically warns against limiting your preparation to highlighted passages, so resist the temptation to study only the sections that look most "testable." Note also that the public handbook was reviewed for this article, not the paid reference books themselves.
Key Takeaway
Treat the S500 as a full-text read, not a skim. The handbook says to study the entire standard, and several tested topics, such as water classes, equipment selection and validation, are built on definitions and decision logic that only make sense when read in context.
A Domain-Ordered Preparation Path
Rather than a generic study schedule, a sensible CSDR plan follows the dependency chain of the material: you cannot design a drying strategy until psychrometry makes sense, and you cannot select equipment until strategy makes sense. Here is one ordering tied to the handbook's own statements. For a fuller methodology, see the CSDR Study Guide 2026.
Foundations: Conduct, Safety and Regulation (Domains 1-2)
- Read the ACAC Code of Conduct closely.
- Work through safety topics: general duty clause, PPE, emergency plans, confined spaces, hazardous atmospheres, working surfaces.
- Read the NIOSH respirator selection logic in the specified locations.
The Science Core (Domains 4-5)
- Drill temperature, humidity, vapor pressure and heat until chart reading is automatic.
- Practice psychrometric chart problems and equilibrium moisture content scenarios for wood and cementitious materials.
- Work through Dalton's evaporation formula and compare open, closed and combination drying strategies.
Equipment and Execution (Domains 3, 6 and 7)
- Match equipment to water class; review air movers, dehumidifiers, portable heating/cooling and HVAC or ductwork.
- Practice dehumidification formulas.
- Study planning, documentation, drying procedures, microbial considerations and validation.
Integration and Self-Testing
- Take timed practice sets that mix all domains under three-hour conditions.
- Review misses against the S500 text rather than just memorizing answers.
You can pressure-test this plan with timed questions on the CSDR Exam Prep practice test site, and keep the CSDR Cheat Sheet nearby for last-week review. Be wary of third-party "question bank" listings you may find on sites like Docsity, Stuvia, StudyGuides.com or Certsarea; a listing being visible tells you nothing about whether the questions are authentic or the answers are correct, and ACAC's own policy page on independent preparation courses is the official reference for what is and is not endorsed.
For testing windows and scheduling logistics, see CSDR Exam Dates 2026, and use our practice exams to build timing discipline before your scheduled sitting.
Frequently Asked Questions
In this context it stands for Council-certified Structural Drying Remediator, a credential issued by the American Council for Accredited Certification (ACAC). Because other credentials share the acronym, include "ACAC" or the full name when you search.
No. The CSDS is the Structural Drying Supervisor credential. The CSDR handbook section contains some inconsistent wording that mentions Supervisor and CSDS, but the credential you are pursuing, and the eligibility rules that apply, are those of the CSDR.
The exam has 120 multiple-choice questions to be completed in three hours, closed book. The passing score is 75%, set using the Modified Angoff Method, and results are delivered immediately and by email.
No. Preparatory training is not mandatory. Eligibility is based on documented structural drying experience, with or without a qualifying science-related degree, plus four project sheets and board approval.
Certification lasts two years. Renewal costs $400 and currently requires 40 recertification credits, made up of 10 for continued field activity and 30 for professional development, plus audit records and a current photo.
For related background, you may also want to read What Is CSDR Certification? and CSDR Training.