RMS Diagnostic Testing & Troubleshooting 2

Question 1

During a block-wall depressurization diagnostic, what is primarily being assessed?

Accepted Answer

Whether hollow cores in block walls can be depressurized as a radon entry pathway

Answer

Block walls with hollow cores can serve as radon entry and transport pathways; diagnostics assess whether those cores communicate and can be effectively evacuated.

Question 2

A diagnostic test reveals very low sub-slab airflow despite a high-powered fan. What is the most likely cause?

Accepted Answer

The sub-slab fill has very low permeability such as clay or fine sand

Answer

Low-permeability sub-slab materials like clay restrict air movement, resulting in poor pressure field extension regardless of fan power.

Question 3

If a mitigation system test pipe shows no pressure differential when the fan is running, what should be checked first?

Accepted Answer

Whether the suction pit properly connects to the sub-slab environment

Answer

No pressure differential typically means the suction pipe is not properly connected to the sub-slab space, or the suction pit opening is blocked or sealed.

Question 4

A crawl space mitigation system shows adequate fan operation, but radon levels remain elevated. Which diagnostic finding is MOST likely?

Accepted Answer

The vapor barrier has holes, gaps, or is not properly sealed to walls and piers

Answer

An incomplete vapor barrier allows radon to bypass the system and enter the living space through gaps or unsealed edges.

Question 5

During troubleshooting, a technician measures higher-than-expected negative pressure but still finds elevated radon levels. What is the most plausible explanation?

Accepted Answer

There is a radon source not addressed by the system such as radon in well water or an isolated sub-slab section

Answer

When system vacuum is confirmed but radon persists, an unconnected radon source such as radon-bearing well water or an isolated sub-slab zone is a key suspect.

(RMS) Radon Mitigation Specialist Practice Test

(RMS) Radon Mitigation Specialist Practice Test

RMS Diagnostic Testing & Troubleshooting 2