RMS Study Guide 2026
Everything you need to pass the RMS exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 RMS Exam Format at a Glance
📚 RMS Topics to Study (63)
✍️ Sample RMS Questions & Answers
1. A homeowner asks why their radon levels increased during winter months after a mitigation system was installed and working. What is the MOST likely explanation?
Winter stack effect increases house depressurization, which can pull more radon into the building even while the mitigation system operates, sometimes requiring fan upgrades.
2. For a commercial building with a crawl space and conditioned slab areas, what combined mitigation approach is typically used?
Combined buildings require sub-membrane depressurization in the crawl space and sub-slab depressurization under slab areas for complete radon control.
3. What does a failing post-mitigation test indicate?
A post-mitigation test showing radon at or above 4 pCi/L indicates the system needs optimization: additional suction points, better sealing, or a more powerful fan.
4. The 'diffusion coefficient' of radon through concrete determines:
The diffusion coefficient quantifies how rapidly radon molecules migrate through the concrete matrix from areas of high concentration to low concentration in the absence of pressure-driven flow.
5. Why is it necessary to measure airflow when installing a radon mitigation system?
Measuring airflow during the installation of a radon mitigation system is crucial for verifying its proper operation and effectiveness. It allows the specialist to confirm that the fan is creating adequate suction and that radon is being effectively drawn from beneath the slab. This measurement helps optimize the system's performance and ensures it meets reduction targets.
6. In a commercial basement with a sump pump, what special consideration applies during SSD installation?
Sump pits can be effective suction points, but the pit must be sealed with an airtight cover penetrated only by the suction pipe to prevent radon from bypassing the system.