Crawl Space Mold Commack, Suffolk County Mar 12
1962 ranch crawl space, 900 sqft. Dirt floor + no vapor barrier = chronic humidity. Installed 10-mil reinforced vapor liner, treated joists, added dedicated dehu.
Remediation Service
Crawl Space Mold Remediation on Long Island
Vapor barriers, joist treatment, dehumidification — the three-step fix for chronic crawl-space mold in older LI homes.
NYLMB Licensed
IICRC Certified
Same-week scheduling
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NYLMB Licensed · MA00534 / MR00612
IICRC CMR & AMRT Certified
4.9★ · 187+ Google Reviews
EPA RRP Lead-Safe
Since 2012 · 2,800+ Homes
Overview
Crawl Space Mold Remediation: what we actually do.
Crawl spaces are where Long Island mold hides. A dirt-floor crawl with no vapor barrier bleeds ground moisture into the joists year-round. Add a cold winter and you get frost on the floor sheathing above. We see this most in 1950s–70s Suffolk ranches and older South Shore homes. The fix is boring: seal the ground, treat the framing, install a dedicated dehumidifier. But it works permanently.
When to call us
- Musty odor coming up through floor registers or floor vents
- Cold, damp flooring above the crawl space
- Mushroom or mold growth on joists, subfloor, or foundation wall
- Standing water or saturated dirt floor
- Humidity readings above 70% inside the crawl
Our process
01
Crawl inspection
Thermal imaging + moisture readings. Humidity meter at multiple zones. Photographic record of joist and foundation-wall conditions.
02
Treat the framing
HEPA-vacuum joists and subfloor, sand visible growth, antimicrobial application, encapsulation coating on heavily-affected wood.
03
Ground seal
10-mil reinforced polyethylene vapor barrier on the dirt floor, sealed to the foundation walls with mastic. Eliminates soil moisture evaporation.
04
Rim-joist spray foam
Closed-cell spray foam on the rim joist seals air leakage and adds thermal break. Prevents winter frost.
05
Dedicated dehumidifier
A commercial crawl-space dehu holding 45–55% RH permanently. The whole-system fix — and the only way to prevent re-growth.
The real causes we see in Long Island homes
No vapor barrier
The simplest and most common cause. Dirt floor crawl spaces on Long Island constantly evaporate soil moisture. Without a vapor barrier, you're essentially running a humidifier under your house.
Failed crawl vents
Vented crawls were standard 1950s–70s. Theory was 'let outside air in to dry things out.' Reality: summer humid air condenses on cool crawl surfaces. Modern building science closes crawls and adds a dehumidifier.
Flooded crawl from a ground-water event
Sandy and subsequent nor'easters pushed ground water into crawls that never properly dried. Insulation stays wet, joists stay damp, mold colonizes.
Pricing
Full crawl-space fix (treat + seal + foam + dehu) usually $2,500–$5,500 depending on square footage. Just treat + seal is $1,800–$3,500. Vapor barrier alone is $800–$1,500.
Every quote is fixed after inspection — no hourly billing, no change orders unless the substrate reveals hidden contamination.See full pricing guide →
Field Log
Recent Crawl Space Mold Jobs
Real jobs. Real towns. Actual scope and scale from our last 90 days of field work.
Crawl Space Mold
Crawl Space Mold Patchogue, Suffolk County Dec 11
1950 bungalow crawl, standing water. Pumped out, spray-foam rim joists, treated joists, vapor liner. Stabilized humidity at 52%.
FAQ
Questions homeowners ask about crawl space mold
Yes — in conjunction with installing a vapor barrier and dehumidifier. Modern building science calls for a conditioned crawl, not a vented one. We seal the vents as part of the fix.
If it's dry and mold-free, sometimes. If it's wet or colonized, it comes out. Replacement is usually closed-cell spray foam on the rim and either batts in joist bays or no insulation with a conditioned crawl (preferred).
A properly-done fix with vapor barrier, spray foam, and dehumidifier will last 20+ years. The dehu filter needs cleaning twice a year — that's the only maintenance.
Usually not — it's treated as a maintenance issue. Exception: flooded crawl from a named storm with a flood policy.
More services
Related work we do.
Mold Remediation
Full IICRC S520 remediation — containment, HEPA filtration, removal, and clearance. Our core service.
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Black Mold Removal
Emergency Stachybotrys removal with negative-air containment, respirator-grade crew, and PRV clearance testing.
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Attic Mold Removal
The #1 mold problem in Long Island homes — sheathing mold from blocked bath fans and under-vented roofs. We treat the wood and fix the ventilation.
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Basement Mold Removal
From crawl-space dampness to finished-basement flood damage. South Shore specialty — Sandy legacy and nor'easter water events.
Read more →
Bathroom Mold Removal
Hidden behind tile, under vanities, and inside wall cavities — most bathroom mold comes from pinhole leaks that have been wet for years.
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Post-Flood Mold Remediation
Category 3 water protocol — Sandy legacy cleanup, storm floods, basement nor'easter events. Insurance-documented from day one.
Read more →
Ready to breathe easier?
Same-week scheduling. Crew on-site in days, not weeks.
Free visual inspection, same-day estimate. Licensed assessor handles the test separately from remediation — NY Article 32 compliant from the first call.
Mon–Sun 7am–8pm · 24/7 emergency line