MRS Removal Techniques & Methods 3 — Questions and Answers
Question 1: When using hand scrubbing to remove surface mold, the scrub brush should be:
- Bagged and discarded or decontaminated after use (Correct answer)
- Rinsed with tap water and reused on other jobs
- Soaked in bleach overnight and stored for future use
- Steam cleaned and returned to the tool inventory
Correct answer: Bagged and discarded or decontaminated after use
Scrub brushes used in mold remediation must be treated as contaminated materials and either discarded or thoroughly decontaminated.
Question 2: Which substrate is considered 'semi-porous' and may sometimes be cleaned rather than removed?
- Solid wood framing lumber (Correct answer)
- Drywall with paper facing
- Fiberglass batt insulation
- Ceiling tile with mineral fiber core
Correct answer: Solid wood framing lumber
Solid wood framing is semi-porous and can often be cleaned by sanding or wire brushing if structurally sound and thoroughly dried.
Question 3: A remediation technician discovers mold on HVAC ductwork lined with fiberglass insulation. The correct action is to:
- Remove and replace the duct liner; clean the outer duct shell (Correct answer)
- Spray the interior with EPA-registered biocide and leave in place
- HEPA vacuum the liner and apply encapsulant
- Seal the duct registers and leave the system off for 30 days
Correct answer: Remove and replace the duct liner; clean the outer duct shell
Fiberglass duct liner cannot be adequately remediated and must be replaced; the metal shell can be cleaned and treated.
Question 4: The term 'source removal' in mold remediation specifically refers to:
- Physically removing mold-contaminated materials from the affected area (Correct answer)
- Eliminating the moisture source that caused mold growth
- Removing occupants from the building during remediation
- Shutting off the HVAC system to prevent spore distribution
Correct answer: Physically removing mold-contaminated materials from the affected area
Source removal means physically removing the mold and contaminated materials, not just addressing the moisture problem.
Question 5: When removing drywall with mold on the back (non-visible) side, the technician should:
- Score and remove in contained sections, keeping contaminated face inward when bagging (Correct answer)
- Pull the entire panel off quickly to minimize exposure time
- Spray the back side with biocide before removal
- Leave in place and treat through injection ports
Correct answer: Score and remove in contained sections, keeping contaminated face inward when bagging
Controlled sectional removal with the contaminated face folded inward minimizes spore release during the removal process.
Question 6: What is the recommended action for wood subfloor decking that has surface mold but remains structurally sound with no delamination?
- Sand or wire brush the surface, HEPA vacuum, clean with antimicrobial, and dry thoroughly (Correct answer)
- Remove and replace all affected panels regardless of structural integrity
- Apply encapsulant without any surface preparation
- Seal with polyurethane floor coating to lock in spores
Correct answer: Sand or wire brush the surface, HEPA vacuum, clean with antimicrobial, and dry thoroughly
Structurally sound wood subflooring can be remediated in place through mechanical cleaning combined with antimicrobial treatment.
Question 7: Media blasting techniques for mold removal are MOST appropriate for which type of surface?
- Rough or irregular surfaces such as exposed framing and joists (Correct answer)
- Smooth painted drywall
- Vinyl floor tiles
- Painted metal ductwork
Correct answer: Rough or irregular surfaces such as exposed framing and joists
Media blasting excels on rough, irregular wood surfaces like exposed framing where manual scrubbing cannot reach all crevices.
MRS Removal Techniques & Methods 3
When using hand scrubbing to remove surface mold, the scrub brush should be: