Radon Mitigation Exam Questions and Answers Already Passed
Simultaneously deployed radon measurements were conducted in the basement and first floor.
The first floor measurement was more than two times higher than the measurement taken in
the basement. What could cause this? - AnswersRadon being released from higher water usage
on the first floor
What would be the most appropriate location for the discharge point of an active soil
depressurization system? - AnswersNot Less than 10 feet above grade
What radon entry mechanism typically causes the greatest amount of radon entry in homes? -
AnswersRadon soil gases drawn into the home because the air pressure inside is lower than the
air pressure in the soil
Air always moves from _____ pressure to ___ pressure. - Answershigher to lower
The greatest health risk from radon generally comes from: - AnswersAlpha particles released
from decay products attached to lung tissue
According to standards, how far above a pitched roof must the exhaust extend above the point
penetrated? - AnswersNot less than 1 foot
According to standards, when the ASD piping is attached to the side of a building, how far above
the edge of the roof must the exhaust extend? - AnswersNot less than 6 inches above the edge
of the roof
After a mitigation system has been installed and activated, what is the minimum waiting time
before beginning a post-mit test? - Answers24 hours
When is the ASD discharge point allowed to be below the roof? (3 rules) - Answers1. Not able to
comply with above the roof requirements
2. Point of exhaust is not less than 20 ft. above grade nearest to the exhaust
3.Radon test is performed in the nearest occupiable area
What material beneath a slab is likely to give you the best success with a sub-slab
depressurization system? - AnswersClean aggregate
After completing a mitigation system, you should inspect the system for compliance with what
3 things? - Answers1. ANSI_AARST Mitigation Standard
2.Conformance with the intended design criteria
3. local statutes and codes
Prior to the installation of a building or airspace pressurization system, what must be performed
,to evaluate system capacity requirements? - AnswersPressure and airflow measurements
(usually a blower door)
Who is required to perform the pressure and airflow measurements prior to installing a building
or airspace pressurization system? - AnswersQualified ventilation professional
A single point sub-slab depressurization system has been installed. The radon was reduced, but
not sufficiently below 4.0. Sub-slab pressures were negative except at a location furthest from
the suction point. The system airflow in the 4-inch vent pipe was 145 cfm. What would be an
appropiate action to take? - AnswersFind locations where excess air is entering the sub-grade
and seal them.
What is an example of a thermal by-pass? (4) - Answerspipe chase, duct chase, unsealed
recessed lights, chimneys
Standards allow for you to give a verbal job proposal? T or F - AnswersFalse. written proposal
What is the minimum distance a measurement device should be placed from an exterior
opening such as a window or door? - Answers3 feet
a Sub-Slab Depressurization system was installed. The U-tube performance indicator showed a
vacuum inside the suction piping below the fam of 0.6 inches of a water column. A few months
later the vacuum has increased to 1.0 inches. What could cause this? - AnswersThe soil beneath
the slab has become wet and is restricting air flow.
A sub-slab depressurization system was installed The system performance indicator showed a
vacuum inside the suction piping below the fan of 0.75 inches of water column. A few months
later the vacuum has dropped to 0.2 inches. What could cause this? - Answersan obstruction in
the discharge pipe.
Besides the mitigators name, address, phone, what are the five items that the written job
proposal must contain? - Answers-description of the proposed system
-long term om&m plan for the proposed design
-costs for initial post-mitigation test & option of 3rd- party testing
-whether the contractor warrants that the system will or will not reduce the radon
concentrations below a specified threshold
-estimate of instillation costs & annual operating costs
Why do mitigation professionals need to understand radon measurement protocols? -
AnswersTests SHALL BE reviewed in developing an appropriate mitigation plan.
What must happen before starting work if you are using sealants, caulks or bonding chemicals
containing volatile solvents? - Answersclient SHALL BE informed to ventilate the work area
, during AND after the work.
What affects the size needed of a suction pit for a sub-slab depressurization system? -
AnswersThe tighter the soil, the bigger pit you need
Why should a radon vent pipe slope back to the suction point? - AnswersTo prevent condensed
moisture from accumulating in the system
What method provides the greatest reduction in exposure to radon while conducting diagnostic
tests with a shop-vac? - Answersplace the shop-vac outside and run the suction hose into the
house
What would be the most effective way to treat an earthen crawl space beneath a home? -
AnswersLay a membrane in accordance with the standard on the crawlspace floor, seal to walls,
draw a vacuum from beneath it.
What must be readily available to the client upon request? - AnswersMaterial Safety Data Sheets
(SDS)q
What are the 5 appropriate mitigation design features that shall be considered on every job? -
Answers1. Practicality
2. Durability
3. Acceptable aesthetics
4. Ease of Service
5. Long Term Cost
What feature would cause great difficulty in employing a sub-slab depressurization system? -
AnswersA home with forced air furnace with return ducts are under the slab.
What best describes the requirements for post-mitigation testing, as described in the AARST
soil gas mitigation standard? - AnswersA short-term test no less than 48 hours in duration, with
the building under closed conditions, starting no earlier than 24 hours but no later than 30 days
after completing the system
Sump lids shall be identified with a label stating what? - Answers"Component of a Radon
Reduction System." Recommended to Do not tamper with or disconnect.
The ANSI-AARST mitigation standard does not recommend caulking and sealing alone to
mitigate radon because: - AnswersIt has not been shown to lower radon levels significantly or
consistently.
According to the ANSI-AARST mitigation standards, the pre-mitigation building investigation is
to include as a minimum: - AnswersSketch of building foundation and indication of system
Simultaneously deployed radon measurements were conducted in the basement and first floor.
The first floor measurement was more than two times higher than the measurement taken in
the basement. What could cause this? - AnswersRadon being released from higher water usage
on the first floor
What would be the most appropriate location for the discharge point of an active soil
depressurization system? - AnswersNot Less than 10 feet above grade
What radon entry mechanism typically causes the greatest amount of radon entry in homes? -
AnswersRadon soil gases drawn into the home because the air pressure inside is lower than the
air pressure in the soil
Air always moves from _____ pressure to ___ pressure. - Answershigher to lower
The greatest health risk from radon generally comes from: - AnswersAlpha particles released
from decay products attached to lung tissue
According to standards, how far above a pitched roof must the exhaust extend above the point
penetrated? - AnswersNot less than 1 foot
According to standards, when the ASD piping is attached to the side of a building, how far above
the edge of the roof must the exhaust extend? - AnswersNot less than 6 inches above the edge
of the roof
After a mitigation system has been installed and activated, what is the minimum waiting time
before beginning a post-mit test? - Answers24 hours
When is the ASD discharge point allowed to be below the roof? (3 rules) - Answers1. Not able to
comply with above the roof requirements
2. Point of exhaust is not less than 20 ft. above grade nearest to the exhaust
3.Radon test is performed in the nearest occupiable area
What material beneath a slab is likely to give you the best success with a sub-slab
depressurization system? - AnswersClean aggregate
After completing a mitigation system, you should inspect the system for compliance with what
3 things? - Answers1. ANSI_AARST Mitigation Standard
2.Conformance with the intended design criteria
3. local statutes and codes
Prior to the installation of a building or airspace pressurization system, what must be performed
,to evaluate system capacity requirements? - AnswersPressure and airflow measurements
(usually a blower door)
Who is required to perform the pressure and airflow measurements prior to installing a building
or airspace pressurization system? - AnswersQualified ventilation professional
A single point sub-slab depressurization system has been installed. The radon was reduced, but
not sufficiently below 4.0. Sub-slab pressures were negative except at a location furthest from
the suction point. The system airflow in the 4-inch vent pipe was 145 cfm. What would be an
appropiate action to take? - AnswersFind locations where excess air is entering the sub-grade
and seal them.
What is an example of a thermal by-pass? (4) - Answerspipe chase, duct chase, unsealed
recessed lights, chimneys
Standards allow for you to give a verbal job proposal? T or F - AnswersFalse. written proposal
What is the minimum distance a measurement device should be placed from an exterior
opening such as a window or door? - Answers3 feet
a Sub-Slab Depressurization system was installed. The U-tube performance indicator showed a
vacuum inside the suction piping below the fam of 0.6 inches of a water column. A few months
later the vacuum has increased to 1.0 inches. What could cause this? - AnswersThe soil beneath
the slab has become wet and is restricting air flow.
A sub-slab depressurization system was installed The system performance indicator showed a
vacuum inside the suction piping below the fan of 0.75 inches of water column. A few months
later the vacuum has dropped to 0.2 inches. What could cause this? - Answersan obstruction in
the discharge pipe.
Besides the mitigators name, address, phone, what are the five items that the written job
proposal must contain? - Answers-description of the proposed system
-long term om&m plan for the proposed design
-costs for initial post-mitigation test & option of 3rd- party testing
-whether the contractor warrants that the system will or will not reduce the radon
concentrations below a specified threshold
-estimate of instillation costs & annual operating costs
Why do mitigation professionals need to understand radon measurement protocols? -
AnswersTests SHALL BE reviewed in developing an appropriate mitigation plan.
What must happen before starting work if you are using sealants, caulks or bonding chemicals
containing volatile solvents? - Answersclient SHALL BE informed to ventilate the work area
, during AND after the work.
What affects the size needed of a suction pit for a sub-slab depressurization system? -
AnswersThe tighter the soil, the bigger pit you need
Why should a radon vent pipe slope back to the suction point? - AnswersTo prevent condensed
moisture from accumulating in the system
What method provides the greatest reduction in exposure to radon while conducting diagnostic
tests with a shop-vac? - Answersplace the shop-vac outside and run the suction hose into the
house
What would be the most effective way to treat an earthen crawl space beneath a home? -
AnswersLay a membrane in accordance with the standard on the crawlspace floor, seal to walls,
draw a vacuum from beneath it.
What must be readily available to the client upon request? - AnswersMaterial Safety Data Sheets
(SDS)q
What are the 5 appropriate mitigation design features that shall be considered on every job? -
Answers1. Practicality
2. Durability
3. Acceptable aesthetics
4. Ease of Service
5. Long Term Cost
What feature would cause great difficulty in employing a sub-slab depressurization system? -
AnswersA home with forced air furnace with return ducts are under the slab.
What best describes the requirements for post-mitigation testing, as described in the AARST
soil gas mitigation standard? - AnswersA short-term test no less than 48 hours in duration, with
the building under closed conditions, starting no earlier than 24 hours but no later than 30 days
after completing the system
Sump lids shall be identified with a label stating what? - Answers"Component of a Radon
Reduction System." Recommended to Do not tamper with or disconnect.
The ANSI-AARST mitigation standard does not recommend caulking and sealing alone to
mitigate radon because: - AnswersIt has not been shown to lower radon levels significantly or
consistently.
According to the ANSI-AARST mitigation standards, the pre-mitigation building investigation is
to include as a minimum: - AnswersSketch of building foundation and indication of system
