Professional Mold Remediation Services
Don't Let Toxic Mold Put Your Family's Health at Risk
Stop mold damage before it spreads. Call now for a free, no-obligation estimate from a local remediation expert.
Free Estimate · Zero Obligation · Available 24/7
[Solved] Does Freezing Mold Kill It
No, freezing does not kill mold. Most mold species become dormant at temperatures below 32°F (0°C) but survive and resume growth once temperatures rise again. Studies show that mold spores can withstand extreme cold, including sub-zero temperatures, for extended periods. Freezing may slow mold growth temporarily, but it is not an effective remediation method. To actually kill mold, you need temperatures above 140°F (60°C), antimicrobial cleaning agents, or professional removal of contaminated materials.
If you’ve researched mold removal methods, you’ve likely heard that heat can kill mold spores, but what about the opposite? Can freezing mold actually kill it?
Short answer: Not really.
Freezing may make mold inactive (dormant), but it does not kill mold permanently. In fact, according to the CDC:
“Fungi, including mold, can be stored at -70°C (-94°F) for long-term preservation.”
, CDC: Preserving Yeast and Mold Isolates
So while freezing may stop mold from growing temporarily, it’s not a reliable method to kill it. That’s why proper removal and remediation, not just freezing, is the key to eliminating mold from your home.
Why Freezing Doesn’t Kill Mold
Mold is resilient. While freezing can suppress mold’s activity, once temperatures rise and moisture returns, mold comes right back. Here’s why freezing doesn’t work on its own:
| Factor | Freezing Effect |
|---|---|
| Spores Killed? | No – Dormant, not dead |
| Growth Stopped? | Temporarily |
| Risk of Return? | Yes |
| Safe Indoors? | Not a practical method |
Instead of using ice or cold temperatures alone, professionals use dry ice blasting, a powerful process combining frozen CO₂, high pressure, and abrasion to remove mold.
What Is Dry Ice Blasting?
Dry ice blasting is a mold remediation technique that uses pellets of frozen carbon dioxide at extremely cold temperatures (around -110°F or -78.5°C). Unlike regular ice, dry ice sublimates, turning directly from solid to gas, leaving no water behind.
It’s a highly effective way to:
- Strip mold off wood, brick, concrete, or metal
- Reach tight spaces (like in crawl spaces or attics)
- Reduce moisture-related secondary damage
EPA Reminder: “Fix the water problem or the mold will come back.”
, EPA: Brief Guide to Mold
How Freezing + Dry Ice Removes Mold
Dry ice blasting removes mold using 4 physical effects:
| Process | How It Works |
|---|---|
| Speed | Ice pellets hit surfaces at high velocity, dislodging mold |
| Abrasion | Kinetic energy breaks mold’s bond with wood, brick, etc. |
| Thermal Shock | Sudden freezing causes spores to shrink and detach |
| Evaporation | CO₂ turns into gas, expanding and lifting debris away |
The result? Less scraping, no harsh chemicals, and minimal surface damage, especially helpful on wood framing, subfloors, or roof sheathing.
When Dry Ice Blasting Works Best
Dry ice blasting is highly effective when:
- Treating mold on framing, sheathing, beams, or subfloors
- Dealing with attic mold, crawl space mold, or large structural infestations
- Sanding or scrubbing would take too long or damage the material
Real-World Example: A 2,000 sq ft attic can often be blasted and cleaned in 1–2 days, while sanding the same area might take 4–5 days and produce more dust.
Pros and Cons of Freezing Mold with Dry Ice
| Benefits | Limitations |
|---|---|
| No secondary waste or water | Requires professional equipment & training |
| Fast, non-invasive | Can’t be used on drywall or soft materials |
| Safe for wood, metal, concrete | Not DIY-friendly |
| Doesn’t damage surfaces when done right | May not fully remove deeply embedded spores |
Compare to Heat-Based Mold Removal
Wondering how freezing compares to using heat? See our guide on whether heat kills mold for a detailed breakdown of thermal remediation methods.
When Not to Use Dry Ice Blasting
Freezing mold with dry ice isn’t always the best choice. Avoid this method if:
- You haven’t fixed the moisture source
- The mold is on drywall, ceiling tiles, or insulation
- You plan to DIY , CO₂ gas can be dangerous in poorly ventilated areas
- The structure is weak or flaking, high pressure may cause damage
NY Dept. of Health: “Materials like drywall, carpet, and insulation that have been moldy should be discarded.”
, NY DOH: Mold Removal Guidelines
How Professionals Use Dry Ice to Remove Mold
Step 1: Containment & Setup
- Use 6 mil plastic sheeting to contain mold spores
- Seal off HVAC vents and entry points
- Set up negative air pressure if indoors
Step 2: Ice Blasting
- Technicians use dry ice guns with various nozzles (fan, precision, etc.)
- Blasting is done on structural wood, subfloors, or sheathing
Step 3: HEPA Vacuum & Sanitizing
- Debris is collected using HEPA vacuums
- Professionals may apply fungicidal sealants to prevent mold return
Tip: After blasting, ask your remediation company if they apply a preventive barrier coating for long-term protection.
Summary: Does Freezing Mold Kill It?
| Method | Kills Mold Spores? | Safe? | DIY Possible? | Lasting Solution? |
|---|---|---|---|---|
| Household Freezing | No | Yes | Yes | No |
| Dry Ice Blasting | Yes (removal) | Only by pros | No | Yes (if done properly) |
Freezing mold may sound like a quick fix, but only dry ice blasting under professional conditions can truly remove mold from structural surfaces without introducing moisture or damage.
Related Resources
Frequently Asked Questions
Does freezing kill mold spores? No. Freezing makes mold spores dormant, but they remain viable. Once temperatures rise and moisture is available, the spores will germinate and resume growth. The CDC notes that mold can be preserved at -70°C (-94°F) for long-term storage.
At what temperature does mold die? Most mold species die at sustained temperatures above 140°F (60°C). Some heat-resistant species may require even higher temperatures. Freezing temperatures do not kill mold — they only pause its growth cycle.
Can mold grow in a freezer? Mold cannot actively grow at freezer temperatures (typically 0°F / -18°C), but it can survive in a dormant state. If food with mold is frozen, the mold will stop growing but will resume once the food is thawed.
Is mold on frozen food safe to eat? No. If food had visible mold before freezing, it should be discarded. Freezing does not destroy mold or its toxins (mycotoxins). Even if the mold appears inactive, the food may still be contaminated.
Does cold weather kill mold in your house? No. Cold winter temperatures may slow mold growth indoors, but they will not eliminate it. Indoor mold problems require proper remediation — fixing the moisture source, removing contaminated materials, and cleaning with antimicrobial agents.
Explore Related Topics:
- Mold Removal Methods
- Air Duct Cleaning For Mold
- How To Get Rid Of Mold In The Bathroom
- How to Get Rid of Mold in Shower
- How to Remove Mold from Clothes and Shoes
Mold Detection Guides
Notice an update we should make?
We strive for accuracy. Contact us here if you see incorrect or outdated info on this page.