How to Clean Flood Damage: A Safe, Step-by-Step Home Guide

When floodwater leaves, the mess stays—and so do hazards you can’t see. Contaminants in the water, compromised wiring and gas lines, and mold that can begin within 24–48 hours turn cleanup into a health and safety challenge. Rushing in with bleach and fans can spread contamination and put you at risk.

This guide gives you a clear, safety‑first sequence to clean flood damage. Assess risks, gear up, document for insurance, stop the water, ventilate wisely, remove standing water and debris, clean and disinfect correctly, dry thoroughly, and verify it’s truly ready to rebuild. Steps follow EPA, FEMA, and IICRC best practices to protect your health and speed recovery.

We’ll also flag what to salvage or discard, how to handle HVAC, electrical, and appliances, how to prevent and remediate mold, local disposal tips, and when to call certified pros. Ready? First, confirm it’s safe to enter.

Step 1. Make sure it’s safe to enter

Before you clean flood damage, treat your home like a hazard zone. Floodwater can carry sewage, chemicals, and debris; structures may be weakened; utilities may be dangerous. Do a cautious, outside‑in safety check and don’t enter until these basics are verified.

• Shut off utilities: Turn off electricity to flooded areas and close the gas supply. Assume downed or wet wires are live. If you smell gas, leave immediately and contact the utility.

• Generator safety: If using a generator, operate it OUTSIDE and at least 20 feet from doors and windows to prevent deadly carbon monoxide.

• Check the structure: Look for foundation cracks, bowed walls, sagging ceilings/floors, sticking doors/windows, and debris overhead. If anything looks off, have a pro inspect first.

• Assume contamination: Treat all floodwater as contaminated. Standing sewage or chemical odors are a stop‑work signal.

• Protect vulnerable people: Children, pregnant people, anyone with asthma, or with weakened immunity should not enter or assist.

If you can enter safely, move on to gearing up properly before any cleanup begins.

Step 2. Gear up: PPE and essential tools

Before you tackle how to clean flood damage, suit up every time you enter. Floodwater can contain sewage, chemicals, and fine mold spores; proper personal protective equipment (PPE) reduces exposure and injuries and keeps contaminants from spreading through your home.

• Respiratory protection: Wear an N‑95 (or higher) respirator; replace it if it’s Dirty, Damaged, Damp, Deformed, or Difficult to breathe in.

• Eye protection: Tight‑fitting goggles without vent holes.

• Gloves: Waterproof outer gloves; heavy‑duty work gloves for debris handling.

• Clothing and footwear: Long sleeves and pants; sturdy, high‑ankle boots with toe protection. Use disposable coveralls if heavy mold is present. Consider a hard hat in unstable areas.

Have these tools ready:

• Containment and cleanup: Contractor bags, plastic sheeting, buckets, mops, scrub brushes, microfiber cloths.

• Water removal: Wet/dry vacuum, submersible pump, squeegee, shovel and push broom for muck.

• Demo and hand tools: Utility knife, pry bar, screwdrivers, tape measure, headlamp/flashlight.

• Cleaning agents: Clean water and detergent first; then an EPA‑registered disinfectant or diluted bleach. Do not mix cleaning products—never bleach with ammonia.

• Drying gear: Dehumidifiers and fans (delay use where visible mold or sewage is present).

• Safety and support: First‑aid kit, soap or sanitizer, potable water, and a moisture meter if available.

Step 3. Document damage for insurance and aid

Once it’s safe and you’re in PPE, pause before cleanup. Thorough documentation is critical for insurance claims and any disaster aid—you need clear, time‑stamped proof of what was damaged, by how much, and what you spent to mitigate further loss.

• Photograph and video everything: Wide shots of each room, then close‑ups of the high‑water line, warped materials, appliances, and serial/model labels.

• Do a narrated walkthrough: State date, address, water depth, visible mold, and any sewage/chemical odors.

• Exterior and property: All four sides of the home, foundation, yard debris, vehicles, and outbuildings.

• Mark the water line: Tape or marker on walls with date for scale.

• Create a room‑by‑room inventory: Items, quantities, and rough replacement values.

• Save damaged materials: Keep samples (e.g., carpet/pad, drywall) and don’t discard major items until your adjuster approves. If health rules require discarding, keep detailed photos and a small labeled sample.

• Keep all receipts: Pumps, PPE, tarps, cleaning supplies, temporary repairs, and professional services; you may need them for reimbursement.

Step 4. Stop the water and stabilize the site

Before you can clean flood damage, you must stop new water from coming in and keep the structure from getting worse. Quick stabilization also reduces contamination spread and protects your claim by showing you acted to prevent further loss.

• Shut off the source: Close the home’s main water valve and isolate any leaking fixtures. If the water is from plumbing, contact a licensed professional promptly.

• Block new intrusion (only if safe): Cover obvious roof or window openings with plastic/tarps, clear exterior drains, and use sandbags or berms to divert runoff away from doors and the foundation.

• Re‑check utilities: Keep power to flooded areas off and gas closed. If using a generator, run it outside and at least 20 feet from any opening.

• Stabilize basements: If a basement is deeply flooded, plan to pump it down in stages—about one‑third per day—to reduce risk of structural damage.

• Protect systems: Do not use the HVAC if any part was submerged or contaminated; have it inspected/cleaned before operation.

• Control access: Keep children, pregnant people, and anyone with asthma or weakened immunity out; mark unstable areas and obvious hazards.

Step 5. Ventilate carefully to reduce exposure

Ventilation helps lower moisture and airborne contaminants, but do it deliberately. If safe, open exterior doors and windows to move air through while you clean and dry. When outside air is very warm and humid, it can slow drying—keep windows closed and rely on powered drying equipment once it’s appropriate to use.

• Expose hidden surfaces: Open inside doors and cabinets; remove drawers to aid drying.

• Avoid spreading contamination: Delay fans/dehumidifiers until after you’ve gently cleaned visible mold; never use fans where sewage is present.

• Protect your systems: Don’t run the HVAC if any part was submerged or contaminated; have it inspected and cleaned before use.

Step 6. Remove standing water safely

Speed matters, but safety comes first. Treat all standing water as contaminated, wear PPE, and keep power to flooded areas off. If you need temporary power for pumps, run a fuel-powered generator only outside and at least 20 feet from doors and windows to avoid deadly carbon monoxide.

• Start with bulk removal: Use pails or a submersible pump to lower the water, then switch to a wet/dry shop vacuum and squeegees to finish surfaces.

• Work carefully: Assume hidden hazards; use a long stick to probe beneath murky water before stepping.

• Basements and deep flooding: Pump down in stages—about one-third per day—to reduce risk of structural damage from pressure changes.

• Discharge wisely: Route water away from the foundation so it doesn’t re-enter the structure.

• Avoid spreading contamination: If sewage is present, do not use fans in that area; ventilate by opening doors and windows only when safe.

• Pause if something seems off: Strong chemical or fuel odors are a stop‑work signal until assessed.

Once the standing water is gone, you’re ready to tackle the muck and debris it left behind.

Step 7. Muck out mud and debris

Now that the water is down, remove the muck fast—bacteria-laden mud and silt become harder to clean as they dry. Stay in full PPE and use methods that keep contaminants out of the air. Focus on loose debris and surface soils first; you’ll handle damaged building materials in Step 9 of how to clean flood damage.

• Shovel before it sets: Scoop out mud and silt before it dries; use a hose on hard surfaces if necessary to float silt for removal.

• Work clean to dirty: Start farthest from the exit and push muck toward the door with shovels, push brooms, and squeegees; keep exits clear.

• Use damp methods: Rinse or wipe surfaces with clean water and detergent first, then use a wet/dry vacuum to collect remaining residue (avoid aggressive scrubbing that aerosolizes dust).

• Stage and contain: Lay plastic sheeting for a debris staging area; double‑bag small contaminated waste in contractor bags and place heavy items on tarps.

• Pre‑sort for disposal: Begin separating debris by type (household trash, construction materials, hazards) to speed curbside removal later.

• Watch for hazards: If you encounter materials that may contain asbestos or lead, or detect sewage/strong chemical odors, stop and get professional guidance before proceeding.

Step 8. Sort contents: what to keep, clean, or discard

Smart sorting limits health risks and speeds drying. As you clean flood damage, separate items by how they absorb water and whether they can be thoroughly cleaned and dried. Keep your PPE on, stage debris on plastic sheeting, and keep taking photos before anything leaves the house so your documentation stays airtight.

• Discard porous items:Carpets, pads, couches, mattresses, curtains, particleboard/pressboard furniture—anything absorbent touched by floodwater.

• Keep and clean non‑porous: Solid wood, metal, glass, and hard plastics; wash with clean water and detergent, then apply an EPA‑registered disinfectant or diluted bleach. Do not mix products.

• Launder textiles: Some washable fabrics may be saved with detergent cycles and complete drying.

• Preserve papers: Freeze wet books and documents in bags with wax paper layers until a conservator can help.

• Toss contaminated food: Discard any food items touched by floodwater.

• Flag hazards: If you suspect asbestos or lead in older items, stop and get professional guidance.

Step 9. Remove water-damaged building materials

Once contents are sorted, open the structure so it can actually dry. Work in full PPE and use damp methods to limit dust. In general, porous building materials that soaked up floodwater must come out; solid wood often cleans and dries.

• Cut drywall high enough: Remove wall finishes from the visible high‑water line plus capillary rise. As a rule, cut at least 12 inches above the watermark (or to the next seam); if you see/measure moisture higher, go up to about 18 inches or more.

• Pull wet insulation: All wet insulation (fiberglass, cellulose, foam) must be removed and discarded to expose studs and cavities.

• Trim and paneling: Pry off baseboards and casing to release moisture. Most paneling will need to be discarded; solid wood trim may be salvaged after cleaning.

• Doors and cabinets: Discard swollen hollow‑core doors and particleboard/pressboard components. Solid wood can often be cleaned and dried.

• Flooring: Remove soaked carpet/pad (already) and any waterlogged or delaminated materials to expose the subfloor for drying.

• Safety first: If you suspect asbestos or lead (common in older homes), stop demolition and get qualified help.

Leave cavities open for cleaning and drying; you’ll confirm dryness with a moisture meter before rebuild.

Step 10. Address HVAC, electrical, and appliances

These systems can turn a bad situation dangerous if handled wrong. Treat every circuit, duct, and motor as contaminated until proven otherwise. Keep power off to flooded areas, don’t run the HVAC if any component or ducting was wet, and never “test” wet appliances. Salvage comes after inspection; otherwise, stage for disposal.

• Electrical: Keep breakers to flooded areas OFF. Do not use wet outlets, panels, or cords. Have a licensed electrician inspect and restore power.

• HVAC: If any part (furnace, air handler, ducts) was submerged or exposed to floodwater, do not operate. Have a professional clean and dry it; replace filters. If the system is verified clean and functional, it can assist drying along with fans/dehumidifiers.

• Appliances: Unplug all units. Do not energize wet refrigerators, washers, dryers, or furnaces. Discard any food touched by floodwater. Gas appliances must be checked before relighting; if you smell gas, leave immediately.

• Generators: Operate OUTSIDE, at least 20 feet from doors/windows to prevent carbon monoxide.

• Large items: If unsalvageable, move appliances to the curb in the “large appliances” debris category per local guidance.

Step 11. Clean surfaces with water and detergent first

With soaked materials out, start “source removal.” The goal is to physically lift dirt and microorganisms off remaining hard, non‑porous surfaces before any disinfectant. Use damp methods that keep contaminants out of the air; avoid aggressive dry scrubbing that aerosols dust or mold. Improve airflow by opening doors and windows if safe, but hold off on fans/dehumidifiers until after you’ve gently cleaned visible mold.

• Work top‑down: Wipe walls, trim, cabinetry, fixtures, then floors.

• Use a damp cloth/sponge: Clean water plus household detergent; change solutions often.

• Rinse and extract: Follow with clean water, then a wet/dry vacuum to remove residue.

• Go gentle first: Loosen soils before switching to stiffer brushes on stubborn spots.

• Check HVAC zones: Don’t stir dust into vents; keep the system off if impacted.

Step 12. Disinfect properly and avoid chemical hazards

After you’ve removed soils with clean water and detergent, disinfect only the clean, hard, non‑porous surfaces. Read every product label, ventilate, and keep children and pets out until surfaces are dry. Most disinfectants are not for unfinished wood, fabrics, or other porous materials.

• Choose the right product: Use an EPA‑registered disinfectant per label, or a household bleach solution for hard, non‑porous surfaces (for example, 1/2 cup bleach to 1 gallon water).

• Mind contact time: Keep the surface visibly wet for the full label “contact time” so it actually works.

• Food‑contact areas: Use a product allowed on food‑contact surfaces and rinse as directed.

• Never mix chemicals: Do not mix cleaners or add bleach to other products (especially ammonia); mixing can create toxic vapors.

• Dilute and use safely: Dilute in a well‑ventilated area, wear PPE, and avoid aerosolizing products while applying.

Step 13. Prevent and remediate mold

Mold can start within 24–48 hours on wet drywall, wood, carpet, and furniture. Protect higher‑risk people (asthma, pregnant, immunocompromised, children) by keeping them out. Stay in PPE: N‑95 respirator, goggles without vents, waterproof gloves, long sleeves, and boots. Ventilate by opening windows and doors if safe, but delay fans and dehumidifiers until you’ve gently removed visible mold so you don’t spread spores.

• Remove what can’t be saved: Discard porous, water‑soaked items with visible mold (carpet, pad, mattresses, particleboard, insulation) that can’t be cleaned and dried quickly.

• Clean first, then disinfect: Wipe hard, non‑porous surfaces with clean water and detergent; rinse/extract residue before any disinfectant.

• Disinfect correctly: Use an EPA‑registered product or diluted bleach on non‑porous surfaces only, keeping surfaces wet for label contact time. Typical dilution: 1/2–1 cup bleach per 1 gallon water. Never mix chemicals.

• Control spread: Bag moldy debris before moving; avoid aggressive dry scrubbing that makes dust airborne.

• Know your limits: Small patches may be DIY; call certified pros if mold covers more than about 10 sq ft, is inside wall/ceiling cavities, affects HVAC, or if strong sewage/chemical odors persist.

Thorough drying is your long‑term mold solution—next, dry the structure completely.

Step 14. Dry the structure thoroughly

Thorough drying is the backbone of how to clean flood damage. After you’ve removed soaked materials and gently cleaned visible mold, set up a controlled dry‑out to stop further damage and prevent regrowth. Keep the HVAC off if any part was submerged or contaminated until a pro inspects it; never use fans in areas with sewage or before that first gentle mold clean.

• Move air the right way: If safe, open exterior doors and windows to promote cross‑ventilation while you work.

• Expose hidden surfaces: Leave wall cavities open; open interior doors and cabinets and remove drawers and toe‑kicks so trapped moisture can escape.

• Use equipment wisely: Deploy fans, dehumidifiers, and/or heaters to speed evaporation and moisture removal. Delay fans where visible mold was present until after gentle cleaning.

• Adapt to weather: If outside air is very humid and warm, close windows and rely on dehumidifiers, air conditioning, and/or heaters instead.

• Be patient: Drying often takes several days to weeks. Keep air moving and do not seal cavities or paint until materials are dry inside and out.

Step 15. Verify dryness before rebuilding

Before reinstalling insulation, drywall, or flooring, confirm the structure is dry inside and out. Hidden moisture fuels mold and ruins new finishes. Use objective tools and simple field tests, and keep documenting results for your adjuster.

• Measure with a moisture meter: Check studs, sill plates, sheathing, cabinets, and subfloors. Rebuild only when readings are 15% moisture content or less.

• Test concrete slabs: Tape all edges of clear plastic sheeting to the slab; wait about 16 hours. If moisture appears under the plastic, it’s still too wet to install flooring.

• Keep cavities open: Do not seal wall cavities, paint, or apply coatings until materials are dry throughout.

• Log your readings: Note locations, dates, and values; continue drying if any area exceeds the target.

When everything consistently tests dry, you’re ready to move on.

Step 16. Handle debris and waste disposal

Debris removal is part safety, part logistics. Keep PPE on, stage waste on plastic sheeting, and keep photographing items before they leave the house. Most communities offer post‑disaster pickup, but rules vary—pre‑sorting speeds curbside removal and reduces re‑handling. Place piles at the curb without blocking streets, sidewalks, mailboxes, meters, hydrants, or storm drains.

• Vegetation: Branches, leaves, and yard waste.

• Household garbage: Bagged trash, food waste, ruined consumables.

• Construction debris: Drywall, insulation, flooring, lumber, cabinetry.

• Large appliances: Refrigerators, washers, dryers, water heaters.

• Electronics: TVs, computers, small devices.

• Household hazards: Oil, paints, solvents, pesticides, batteries.

Double‑bag small contaminated items; tag sewage‑contaminated waste if required locally. Keep hazardous materials separate for special collection. When in doubt, ask your city before moving piles.

Step 17. Restore utilities and safeguard for the future

When materials test dry and hazards are cleared, bring systems back online methodically. Restoring utilities the right way prevents re-contamination and protects your investment in how to clean flood damage. Use licensed pros where required and keep vulnerable people out until everything is verified safe.

• Electric and gas: Have a licensed electrician inspect panels, outlets, and circuits before energizing. If you smell gas, leave and call the utility; relight gas appliances only after professional inspection.

• HVAC: If any component or ducting was wet, do not run it until professionally cleaned and dried; replace filters and consider duct cleaning.

• Water and plumbing: Flush lines until clear. Disinfect food-contact surfaces. If you have a private well that flooded, consult local health guidance on well disinfection.

• Safety upgrades: Install CO and smoke alarms, GFCI/AFCI protection, and water leak alarms. Add a sump pump with battery backup, backflow prevention, and elevate critical equipment. Keep a generator OUTSIDE, at least 20 feet from openings. Improve grading and choose moisture-tolerant finishes during rebuild.

Step 18. Know when to call certified professionals

DIY stops where safety, contamination, or hidden damage begins. The EPA advises getting experienced help for flooded homes—especially if vulnerable people are involved. Bringing in certified pros protects your health, preserves your claim, and prevents costly do‑overs.

• Structural red flags: Cracked foundations, bowed walls, sagging floors/ceilings. Call a structural engineer or licensed contractor.

• Electrical/gas hazards: Wet panels/outlets, tripped breakers, gas odors. Call a licensed electrician and utility/gas company.

• HVAC impacted: Any submerged or contaminated components/ducts. Call an HVAC contractor; don’t run the system.

• Mold you can’t manage: Growth inside cavities/HVAC or areas larger than a small patch. Call IICRC‑certified mold/water damage pros.

• Sewage/chemical contamination: Strong odors or known spills. Stop work and bring in specialists.

• Asbestos/lead suspects (older homes): Textured ceilings, vinyl tiles, mastics, lead paint. Call accredited abatement professionals.

Ask for IICRC, ACAC, AIHA, or similar credentials, verify insurance, and check references before work begins.

Next steps

You’ve stabilized, documented, cleaned, and set drying in motion—now keep momentum. Over the next 48–72 hours, monitor humidity, empty dehumidifiers, and log moisture readings until framing and subfloors are at or below 15%. Schedule debris pickup, verify your HVAC and electrical inspections, and keep cavities open. Resist priming or painting until repeated meter checks stay dry. Keep photographing progress and saving every receipt for your claim.

If the scope feels bigger than your bandwidth—or you’re facing sewage, widespread mold, or impacted HVAC/electrical—bring in certified help. We offer 24/7 emergency response, IICRC‑certified crews, and free estimates across Greater Austin. When minutes matter, call Water Damage Repair Tech for fast, safe recovery.