Dry ice blasting physically removes visible mold growth, hyphae, and spore mass from porous and semi-porous structural materials — framing lumber, joists, subfloor, masonry. It is one of the most effective mechanical removal methods in the IICRC S520 toolbox. What it does not do is kill mold or sanitize the substrate. Those are separate steps in any code-compliant remediation.
Why dry ice works on mold
Mold colonies sit on the surface and just inside the top fibers of porous materials. Dry ice pellets impact, thermally embrittle, and lift the colony off the substrate without driving water deeper into the wood — which is the failure mode in wet remediation methods. The CO₂ sublimates, so there's no secondary moisture to feed regrowth and no spent media to capture spores in.
Where dry ice fits in IICRC S520
- Source removal step — physically extracting the visible contamination after containment is set
- Pre-treatment cleanup before antimicrobial application, so the chemistry contacts substrate, not surface debris
- Final structural cleaning before reconstruction and post-remediation verification (PRV) testing
What dry ice does not do
- It does not kill mold — that's the antimicrobial step
- It does not address the moisture source — that's the dehumidification and structural drying step
- It does not replace IEP clearance testing — we coordinate with third-party assessors but don't self-clear our own work
- It does not remove staining where the pigment has penetrated the wood — that's cosmetic and sometimes left for the rebuild
Why this matters for the carrier
Insurance carriers and IEPs accept dry ice as a source-removal method when it's documented inside an S520-compliant scope. We bring photo logs, scope sheets, and pre/post imagery formatted so the adjuster and the IEP can audit the work without back-and-forth. The method is well-precedented; the documentation is what gets the claim approved.
When to bring us in
After containment and HEPA negative-air are set, and before antimicrobial application. We coordinate directly with the remediation contractor or work as the source-removal sub on their behalf.