A flood in Nassau doesn't get better by waiting, and the cost of delay is measured in thousands of dollars of preventable damage. COS Water Damage Restoration's Nassau-based Water Damage Repair teams are on standby 24/7 with equipment staged and crews briefed.
Positioned in Nassau for fast local response every time.
Every technician holds current WRT certification — the industry standard.
No hidden fees, no last-minute line items.
We build your claim file and deal with your adjuster directly.
We've handled everything from flash-flood basement extractions in Nassau's older neighborhoods to multi-floor commercial water events in newer construction, and every job has reinforced the same core truth: speed and expertise make the difference between a manageable repair and a catastrophic rebuild.
We bring enterprise-grade extraction and drying equipment to every Nassau job — not the rental-store grade equipment that leaves moisture in wall cavities and under flooring that causes mold weeks after the job was supposedly done.
COS Water Damage Restoration has earned the trust of Nassau homeowners, landlords, property managers, and commercial facility owners because we consistently do what we say we'll do: we arrive when we say we'll arrive, we provide the estimate we quoted, we complete the documentation we promised, and we stand behind the work with a written satisfaction guarantee.

Every service listed below is available 24/7 in Nassau — no wait lists, no "call back during business hours," no sending you to a subcontractor we can't vouch for.
Our truck-mounted extraction systems can pull high volumes of water in a fraction of the time it would take with consumer-grade equipment — getting the visible water out fast while our moisture detection team maps the water you can't see yet. Nassau's Water Damage Repair emergency calls include everything from clean water supply line failures to contaminated sewage backflows, and our crews are trained and equipped for every category of water damage — with the right PPE, containment protocols, and extraction methods for each situation.
Our residential restoration teams in Nassau are experienced across the full range of home types found in the area — older homes with original hardwood and plaster, newer construction with engineered materials and finished basements, and everything in between. Daily check-ins from your project manager keep you informed throughout the drying cycle, and reconstruction doesn't begin until documented moisture readings confirm every structural assembly has reached target levels.
We work in occupied buildings, schedule around your operating hours when it's possible to do so safely, and produce the detailed loss documentation that commercial insurance adjusters require — all as standard practice, not a premium option. Whether the loss is a small office suite or an entire floor of a commercial building, COS Water Damage Restoration's Nassau commercial team has the experience and equipment to handle it.
Mold is the almost-inevitable consequence of water damage that wasn't addressed quickly or completely — and in Nassau's climate, wet building materials can support mold growth in as little as 24 to 48 hours after initial exposure. Post-remediation air quality testing provides objective confirmation that the remediation was successful, and the written clearance report we issue becomes part of your property's maintenance record.
The goal of structural drying isn't just to make the air feel dryer or to run fans for a few days — it's to return every material in the affected area to its documented equilibrium moisture content, verified by calibrated instruments, before any reconstruction begins. Your project manager reviews the daily readings with you or provides them by phone or message on request, and reconstruction planning begins only after final readings confirm compliance with drying targets across all affected assemblies.
Nassau property owners dealing with water damage face two simultaneous challenges: the physical restoration of their property, and the administrative challenge of filing and navigating an insurance claim. If your adjuster's initial settlement offer doesn't fully account for the documented scope of loss, we prepare and file a supplement with supporting evidence — a step that many homeowners don't know they can take and that frequently results in additional covered compensation.



Don't wait to call — our Nassau emergency line is live 24/7 and help is closer than you think.
📞 Call +1-844-499-0972 — Nassau Emergency LineWhen water damage hits in Nassau, the decision you make in the first 30 minutes — who you call and how fast they show up — will define the entire scope and cost of your restoration experience.
We're not a call center forwarding your Nassau emergency to a regional contractor — we have crews stationed locally in Nassau, ready to deploy immediately.
Our Nassau dispatch target is 60 minutes or less from your call to a crew at your door — and we hit that target consistently because we're positioned locally, not dispatched from another city.
Flat-rate pricing means the number on your estimate matches the number on your final invoice, assuming no scope changes.
Your Nassau home or business deserves the professionalism that certification represents.
We invest in the equipment that produces the outcomes our Nassau customers review five stars for.
We file the claim, deal with the adjuster, and fight for a fair settlement — so you don't have to learn the insurance claims process on top of dealing with a flooded property.
Five-star reviews are earned, not purchased — and they reflect what happens when every technician takes personal pride in the outcome of every job.
No being transferred between departments, no explaining your situation to a new person every time you call, no wondering who's responsible.
Every Water Damage Repair job in Nassau follows the same structured process — one we've refined over thousands of local jobs to be as fast, thorough, and transparent as possible.
You receive your crew's estimated arrival time before you hang up, and a direct callback number if anything changes en route.
Our crew arrives at your Nassau property and immediately begins a systematic assessment — identifying every water entry point, mapping moisture migration with detection instruments, and classifying the water category (clean, gray, or black water).
We extract completely and transition directly to drying setup without an overnight gap where mold begins to grow.
A calculated drying plan is implemented immediately following extraction — air movers and dehumidifiers placed based on psychrometric data specific to your Nassau property's materials and conditions.
Antimicrobial treatment is applied to all moisture-exposed surfaces as a standard preventive step — stopping mold colonization before it can take hold in your Nassau property's structural assemblies.
The final walkthrough is conducted with you personally, confirming satisfaction with every element before we close out the job and hand you your warranty documentation.
When a restoration company sends a crew to your Nassau property who has never worked in the area, the difference in performance is real — and it shows up in ways that matter: slower navigation to your address, unfamiliarity with local building code requirements that affect how drying and reconstruction are approached, no relationship with local supply vendors that allows materials to be sourced quickly, and no reputation to protect within the community they're serving.
Our Nassau technicians bring this material-specific knowledge to every assessment and use it to build drying plans that work for your specific property rather than applying a generic template.
That local context makes our assessments more accurate, our response timelines more reliable, and our client communication more informed.
Water damage restoration costs in Nassau vary based on several factors: the volume of water, the category of water (clean vs. contaminated), the materials affected, the square footage involved, and the extent of mold risk. Most residential water damage events in Nassau fall within a range that homeowner insurance covers significantly, which is why our insurance coordination service is so valuable — we help make sure your policy pays what it should so your out-of-pocket is minimal. Call +1-844-499-0972 for a free on-site estimate with no obligation to proceed — we'll give you a clear picture of scope and cost before you commit to anything.
If you're a property owner in Nassau who has just discovered water damage — whether it's an active flood or moisture you noticed during an inspection — your best first call is +1-844-499-0972.
📞 Call +1-844-499-0972 — Free Nassau Assessment

Real reviews from Nassau, NY property owners who called COS Water Damage Restoration when water threatened their homes and businesses.
"We had a washing machine overflow that soaked the laundry room and wicked into the adjacent bedroom overnight before we noticed it. I found it in the morning and called COS Water Damage Restoration immediately. Their crew was at my Nassau house in 55 minutes — which was remarkable given that I called at 7 a.m. on a Saturday. They found moisture under the bedroom baseboard that I never would have caught, set up drying equipment that ran for five days, and the project manager called me with readings every morning. No mold, no lingering smell, and the claim went through without a single request for additional documentation. Absolute professionals."
"The burst pipe situation in our Nassau rental unit was a nightmare — the tenants called me at midnight, the unit was partially flooded, and I had no idea how bad it was. COS Water Damage Restoration's crew was on site before I could even get there myself. By the time I arrived, extraction was underway and the project manager was already walking through the damage assessment with photos. I had a full scope and estimate in my email before 2 a.m. The restoration was completed on schedule, within the estimated cost, and my tenant was back in the unit within two weeks. Outstanding."
"Mold found during the renovation of our Nassau home led us to COS Water Damage Restoration for remediation. The discovery was stressful — we didn't know how extensive it was or what it meant for the timeline of our project. The COS Water Damage Restoration team came in, assessed it thoroughly, explained exactly what they found and what the IICRC-compliant remediation process looked like, and completed the job on time. The post-remediation air testing came back clear, the report they provided satisfied our contractor and our insurer, and we were back on schedule within a week. Professional from beginning to end."
Questions about Water Damage Repair in Nassau? Here are the ones we answer most often — covering response times, pricing, insurance, what to do in an emergency, and what separates COS Water Damage Restoration from other contractors in the area.
Our coverage extends beyond Nassau proper to include nearby communities where our Nassau-based crews can respond quickly and deliver the same high-quality service.
Give us a call to confirm service at your specific location in or near Nassau.
📞 Call +1-844-499-0972 — Confirm Nassau CoverageWhether it's 3 a.m. or the middle of a holiday weekend, our Nassau crew is on standby, briefed, and ready to deploy. One call to +1-844-499-0972 puts licensed, certified water damage professionals at your door within the hour.
📞 Call +1-844-499-0972 — Nassau Emergency Response24/7 Live Dispatch · Licensed & Insured in Nassau, NY · No Voicemail · Free Assessment