- The credential is ICRI Concrete Slab Moisture Testing Technician-Grade 1, covering five ASTM-based test methods.
- Certification requires a written exam plus performing all five tests before a qualified judge without coaching.
- Published 2026 full-course fees are USD 1,050 member, USD 1,350 non-member, USD 510 verified student member.
- Certification lasts five years; first recertification is written-exam-only, later ones require the full course.
The Credential at a Glance
This one-page review covers the Concrete Slab Moisture Testing Technician credential administered by the International Concrete Repair Institute (ICRI). The exact name is ICRI Concrete Slab Moisture Testing Technician-Grade 1. It is a hands-on field credential for people who measure moisture and alkalinity conditions in concrete slabs before flooring goes down. If you are new to the program, What Is CSMT Certification? gives the plain-language background, and this article assumes you want the fast, fact-dense version.
Two things make this credential different from a typical multiple-choice certification. First, passing is not only a test of knowledge: you must successfully perform all five test methods in front of a qualified judge, without coaching. Second, the written exam sits alongside an education session, so the content you must absorb is both conceptual (why slabs hold moisture, how flooring fails) and procedural (exactly how each ASTM method is carried out).
The Five Test Methods in One Table
Everything in the program hangs on five ASTM standards. Memorize what each one measures and whether it is destructive, because exam and performance questions frequently turn on that distinction.
| Standard | What It Covers | What You Are Really Doing |
|---|---|---|
| ASTM F710 (Section 5.2) | Preparing concrete floors to receive resilient flooring; pH testing | Checking surface alkalinity as part of slab readiness |
| ASTM F1869 | Moisture vapor emission rate using anhydrous calcium chloride | Measuring vapor leaving the slab surface over a set period |
| ASTM F2170 | Relative humidity in concrete slabs using in situ probes | Measuring humidity inside the slab at depth |
| ASTM F2659 | Preliminary comparative evaluation with a non-destructive electronic moisture meter | Screening and comparing areas without drilling |
| ASTM F3191 | Field determination of substrate water absorption (porosity) | Judging how absorptive the substrate is before flooring or adhesive goes on |
For a deeper look at how these five areas map to the credential, see the CSMT exam domains guide.
Domain-by-Domain Must-Know Facts
Domain 1: ASTM F710 - Preparing Concrete Floors to Receive Resilient Flooring; Section 5.2 pH Testing
F710 is the broad slab-preparation standard, and the credential focuses on its Section 5.2 pH testing provisions. ICRI retains the Section 5.2 reference exactly as it lists it, so study it as supplied in your candidate materials.
- Understand why surface alkalinity matters to flooring adhesives and finishes.
- Know that pH is a surface-condition check, distinct from the moisture measurements in the other four methods.
- Be able to explain how pH results fit into a flooring-readiness decision, not just how to read a number.
Domain 2: ASTM F1869 - Moisture Vapor Emission Rate Using Anhydrous Calcium Chloride
This is the classic calcium chloride test. A sealed dish of desiccant sits on the slab surface for a defined period, and the weight gain reflects moisture vapor leaving the slab.
- Focus on setup discipline: surface preparation, conditioning of the space, and handling of the dish.
- Know that the result is a rate over time, which is why test duration and precise weighing matter.
- Expect to be judged on technique, because small handling errors corrupt the reading.
Domain 3: ASTM F2170 - Relative Humidity Using In Situ Probes
In situ probe testing measures relative humidity inside the slab rather than at the surface, which makes it procedure-heavy.
- Know that it involves drilling holes, installing sleeves or probes, and allowing the environment in the hole to equilibrate before reading.
- Understand why depth and placement matter: the reading represents conditions within the slab, not the air above it.
- Practice the sequence until you can describe each step in order without notes.
Domain 4: ASTM F2659 - Preliminary Evaluation with a Non-Destructive Electronic Moisture Meter
This method is a screening tool. The key word in the title is preliminary: it compares areas of a slab quickly and without damage, but it is not a substitute for the quantitative methods.
- Know where a meter is useful (locating wet or suspect zones) and where it is not (final acceptance decisions).
- Understand that results are comparative, which is why readings are interpreted relative to one another.
- Be ready to explain why a meter might guide where to run F2170 or F1869 tests.
Domain 5: ASTM F3191 - Field Determination of Substrate Water Absorption (Porosity)
F3191 evaluates how readily the substrate absorbs water, which bears on whether flooring products will bond properly.
- Learn the purpose of the test before the steps: absorption tells you about surface porosity, not slab moisture content.
- Be able to contrast porosity with the moisture-vapor and humidity measurements from Domains 2 and 3.
- Practice the field procedure, since it is among the five tests you must perform before a judge.
Key Takeaway
Sort the five methods by question answered: pH and porosity describe the surface, F1869 describes vapor leaving the surface, F2170 describes humidity inside the slab, and F2659 screens broadly. If you can state that one-liner for each, you hold the conceptual backbone of the program.
Exam Format and Timing
The program has three distinct pieces, and candidates often blur them together:
- Education session: roughly three to four hours. This is instruction, not examination time.
- Written examination: the published schedule allocates one hour.
- Performance appointment: a separate, assigned one-hour appointment in which you perform all five tests before a qualified judge, without coaching.
ICRI has not published a verified written question count or numeric passing threshold that this site can cite, so be wary of any source that quotes one confidently. For the specifics of what is and is not publicly known, see CSMT Passing Score 2026 and CSMT Pass Rate 2026. Because the performance component is pass/fail on technique, your preparation should include repetition with the actual equipment, not just reading.
Eligibility, Fees and Registration Mechanics
Eligibility comes through one of two routes: ICRI-approved previous hands-on testing experience, or a prequalification waiver obtained through participation in the Demonstration and Workshop. The full details are in CSMT Requirements 2026.
Published 2026 full-course fees include the education session and the demonstration/workshop:
| Category | Full-Course Fee (USD) |
|---|---|
| ICRI member | 1,050 |
| Non-member | 1,350 |
| Verified student member | 510 |
Courses are offered at scheduled events hosted at partner locations. One example listed by ICRI is a November 4-5, 2026 session at Structural Technologies in the Baltimore, MD area, which corroborates the fee structure. Check the ICRI program page for current dates, and see CSMT Exam Dates 2026 and the CSMT certification cost breakdown for planning.
Retake Windows and Recertification
If you fail the initial attempt
- A failed written examination must be retaken in full.
- If only a performance method is failed, just that method is repeated.
- Retakes must happen within one year, or the full certification course must be repeated.
Staying certified
Certification lasts five years. The renewal path changes after the first cycle:
| Stage | Requirement | Fee (USD) |
|---|---|---|
| First recertification | Written exam only | 495 member / 595 non-member |
| Second and later recertifications | Full certification course | 695 member / 895 non-member |
A failed first-recertification written exam carries its own six-month re-examination deadline before the full course is required. One wrinkle worth knowing: ICRI's page has a later-renewal heading referencing "10+ years after first recertification," which conflicts with the explicit five-year cycle. It does not establish ten-year certification validity, so plan around five years.
Who Uses This Credential
The credential is aimed at people who test slabs before flooring is installed. In practice that points to flooring contractors and installers, concrete and moisture-mitigation specialists, testing and inspection firms, and general contractors or consultants who need defensible slab-readiness documentation. Having a certified technician can matter when flooring warranties, specifications, or disputes hinge on whether testing was done correctly. For the employment angle, see CSMT Jobs; for earnings context, the CSMT salary guide; and for a value judgment, Is the CSMT Certification Worth It? This site does not cite specific salary figures because none are verified for this credential.
A Domain-Ordered Four-Week Plan
Generic study advice is less useful here than ordering the material by how each method behaves. This is the one scheduling suggestion in this article; adjust it around your own course date. For fuller guidance, read the CSMT study guide.
Surface Conditions: F710 pH and F3191 Porosity
- Learn why alkalinity and absorption affect flooring bond.
- Rehearse both procedures aloud, step by step.
Vapor Emission: F1869 Calcium Chloride
- Memorize setup, placement, duration, and handling sequence.
- Practice with the equipment if you can access it.
In-Slab Humidity: F2170 Probes
- Walk through drilling, installation, equilibration, and reading in order.
- Contrast its meaning with F1869 results.
Screening and Integration: F2659 Plus Full Run-Throughs
- Learn where the meter fits as a preliminary tool.
- Run all five tests in sequence, then take timed practice questions at our practice test site.
Costly Mix-Ups to Avoid
- Importing another credential's facts. The acronym CSMT is shared by other, unrelated certifications. Fees, dates, pass rates, and domain lists from those do not apply here. Everything in this article refers only to the ICRI Concrete Slab Moisture Testing Technician program. If you need the terminology sorted out, see What Does CSMT Stand For?
- Using outdated reference lists. Some older materials include ASTM F2420. Use the editions supplied to registered candidates instead of substituting newer editions or legacy lists.
- Treating the meter as a final answer. F2659 is a preliminary, comparative tool.
- Assuming the online course counts. It does not credit toward certification.
- Neglecting hands-on repetition. The judge evaluates performance, and you cannot be coached mid-test.
- Misreading renewal. Plan on a five-year cycle and budget for the correct recertification path.
If you are weighing how demanding all this is, How Hard Is the CSMT Exam? discusses the difficulty drivers, and CSMT Training covers preparation options.
Frequently Asked Questions
Here it means Concrete Slab Moisture Testing Technician, specifically ICRI Concrete Slab Moisture Testing Technician-Grade 1. The same acronym is used by unrelated credentials, so make sure any fee, date, or pass-rate source you rely on is about the ICRI program.
No. Certification requires passing the ICRI-administered written examination and successfully performing all five tests before a qualified judge without coaching. The schedule allocates one hour to the written exam and a separate one-hour performance appointment.
Published full-course fees, including the education session and the demonstration/workshop, are USD 1,050 for ICRI members, USD 1,350 for non-members, and USD 510 for verified student members. Recertification costs are separate.
Certification lasts five years. First recertification is a written exam only (USD 495 member, USD 595 non-member). Second and later recertifications require the full certification course (USD 695 member, USD 895 non-member).
No. The separately sold online Education Course does not lead to certification and cannot be credited toward the certification program, so it is not a shortcut to the credential.
For a broader orientation before you register, start with What Is CSMT?, then build your recall with timed questions at CSMT Exam Prep.