Updated on 12-Sep-2025
Vinyl plank flooring is durable and stylish, but it can trap moisture underneath, creating a hidden risk of mold. Preventing mold requires quick spill cleanup, proper underlayment, humidity control, and professional mold inspection after water damage. These steps keep Toronto homes safe from costly floor replacement.
Vinyl plank flooring is one of the most popular choices for Toronto homeowners, thanks to its affordability, waterproof surface, and easy installation. However, its impermeable design means that any moisture trapped underneath cannot evaporate. Over time, this hidden dampness creates the perfect environment for mold growth under flooring materials.
This guide explains the most effective ways to prevent mold under vinyl plank floors, helping you protect both your investment and your family’s health.
Table of Contents
Why Mold Develops Under Vinyl Plank Flooring
- Moisture intrusion: Leaks from appliances, sinks, or basement seepage.
- Trapped water: Vinyl planks lock tightly, sealing in spills.
- Improper underlayment: Foam or cork pads that absorb and hold moisture.
- High indoor humidity: Especially in basements or during Toronto’s humid summers.
➡️ Takeaway: Mold prevention starts with controlling moisture—the one ingredient mold needs to thrive.
Checklist: How to Prevent Mold Under Vinyl Plank Flooring
- Clean spills immediately – never let water sit between planks.
- Fix leaks fast – from dishwashers, sinks, or nearby plumbing.
- Use a moisture barrier underlayment – vapour barriers prevent slab or basement moisture from reaching planks.
- Control humidity indoors – keep relative humidity below 50% with dehumidifiers.
- Improve ventilation – especially in kitchens, bathrooms, and basements.
- Inspect flooring regularly – check for soft spots, musty odours, or lifted planks.
- Schedule professional checks – after floods or water damage, have a certified inspector assess subfloors.
Best Underlayment Choices for Mold Prevention
- 6-mil polyethylene vapour barrier – ideal for concrete slab installations.
- Closed-cell foam underlayment – resists moisture absorption.
- Combination underlayment with vapour layer – dual protection against sound and moisture.
➡️ Pro Tip: Avoid cork or felt underlayments in humid areas—they absorb water and increase mold risk.
Where Mold Prevention Matters Most in Toronto Homes
- Basements – prone to slab seepage and high humidity.
- Kitchens & Bathrooms – water spills and appliance leaks are common.
- Apartments with concrete subfloors – vapour transmission from slabs is a hidden risk.
What to Do After Water Damage
- Act within 24–48 hours – mold can begin growing quickly.
- Remove planks in affected areas for inspection.
- Dry subfloor completely with fans or dehumidifiers.
- Call a professional mold remediation team in Toronto, if odours or visible mold appear.
FAQ – Preventing Mold Under Vinyl Plank Flooring
Q1: Is vinyl plank flooring itself mold-proof?
Yes, vinyl is waterproof, but the space underneath can trap moisture and allow mold to grow.
Q2: Can I install vinyl planks directly over concrete?
Only if you use a vapour barrier underlayment to block moisture from the slab.
Q3: How often should I check for hidden mold?
At least once a year, and immediately after any leaks or flooding.
Q4: What’s the biggest mistake homeowners make with vinyl flooring?
Skipping a moisture barrier underlayment, especially in basements.
Vinyl plank flooring is a smart choice for Toronto homes, but it requires moisture control to stay mold-free. Quick cleanup, proper underlayment, humidity control, and professional inspections after leaks are the key to long-lasting floors.
👉 Need help preventing or treating mold under your vinyl flooring in Toronto? Contact us for expert inspection and remediation.