CSLB C-33 Painting & DecoratingSurface PreparationHard
A painting contractor is preparing a residential bathroom for painting. The client reports a history of recurring mold and mildew on the walls and ceiling due to high humidity. After thoroughly cleaning and removing the existing mold, what type of primer should be used to inhibit future growth and ensure a durable finish?
- AStandard acrylic latex primer
- BPVA (Polyvinyl Acetate) primer
- CMold and mildew resistant primer
- DOil-based enamel undercoater
Show answer & explanationAnswer & explanation
Correct answer: C. Mold and mildew resistant primer
Mold and mildew resistant primers contain fungicides and mildewcides that inhibit the growth of mold and mildew on the paint film, making them essential for high-humidity environments like bathrooms, especially where there's a history of fungal growth.
Why the other options are wrong
- A. Standard acrylic latex primers do not contain sufficient protective additives to inhibit mold/mildew growth effectively in problem areas.
- B. PVA primers are for drywall sealing and offer no mold/mildew resistance.
- D. Oil-based undercoaters offer good adhesion but lack specific fungicidal properties to prevent mold and mildew recurrence.
Mold & Mildew Resistant Primer
A primer formulated with antimicrobial additives (fungicides/mildewcides) to prevent the growth of mold and mildew on the paint film, especially in high-humidity areas.
- Crucial for bathrooms, kitchens, basements.
- Does not kill existing mold, only prevents future growth.
- Must be applied to a clean, mold-free surface.
Memory trick: For damp walls, only 'mold-resistant' primer can win.