Water Damage: What to Do in the First 24 Hours

In the first 24 hours after water damage, protect people first, stop the water source if safe, avoid electrical and contaminated-water hazards, photograph the loss, notify your insurer, move vulnerable contents without discarding evidence, and begin professional extraction and drying. Do not wait for visible mould or assume walls and floors are dry because surfaces look normal.

By Firstline Restoration
Last updated: July 24, 2026

The first day is about stabilization and evidence, not rushing into a complete rebuild. A calm sequence protects health, limits spread, and gives the insurer and restoration team a clearer record of the original condition.

What should you do during the first 24 hours?

Time	Priority	Action
First 15 minutes	Life safety	Keep out, assess electricity and contamination, stop source if safe
First hour	Contain and report	Call emergency help and insurer, prevent further flow
Hours 1 to 4	Document and extract	Photos, inventory, water removal, moisture assessment
Hours 4 to 24	Dry and monitor	Equipment, selective access, readings, written scope

What affects the first 24 hours after water damage most?

Electrical exposure

Standing water near panels, outlets, appliances, furnaces, or wiring can be dangerous. Do not enter to reach a submerged panel. This factor should be documented during the initial assessment because it can change drying, removal, cleaning, reconstruction, or claim handling. A clear scope states what was observed, what must be verified, and what would change the plan.

Contamination

Sewage, drain backup, outdoor floodwater, and water that passed through dirty assemblies require more protective handling than a fresh supply-line leak. This factor should be documented during the initial assessment because it can change drying, removal, cleaning, reconstruction, or claim handling. A clear scope states what was observed, what must be verified, and what would change the plan.

Hidden spread

Water moves under flooring, through wall cavities, around ducts, and into insulation, so the visible puddle may be a small part of the loss. This factor should be documented during the initial assessment because it can change drying, removal, cleaning, reconstruction, or claim handling. A clear scope states what was observed, what must be verified, and what would change the plan.

Vulnerable occupants

Children, seniors, people with respiratory conditions, and pets should stay away from affected and dusty work areas. This factor should be documented during the initial assessment because it can change drying, removal, cleaning, reconstruction, or claim handling. A clear scope states what was observed, what must be verified, and what would change the plan.

What do Canadian guidance and current industry sources say?

Health Canada's 2023 guide says mould can begin growing within 48 hours where excessive moisture is present. Source: Health Canada, Guide to Addressing Moisture and Mould Indoors, January 2023.

Health Canada recommends maintaining indoor relative humidity between 30 and 50 percent and addressing dampness and flooding promptly. Source: Health Canada mould guidance, accessed July 2026.

These sources provide a sound baseline, but every loss is site-specific. The source, duration, affected materials, contamination, hidden moisture, building age, access, and policy wording can change the correct response. Health questions belong with a healthcare professional, and coverage questions belong with the insurer or broker.

What should you do step by step?

1. Protect people. Keep occupants out of unsafe areas and call emergency services or the utility when electrical, structural, gas, or fire hazards are suspected. Record what happened, who was contacted, and what action was taken. That creates a useful timeline for the homeowner, property manager, restoration team, and insurer.
2. Stop additional water. Close a local valve or main only when it can be reached safely, and stop using drains during a backup. Record what happened, who was contacted, and what action was taken. That creates a useful timeline for the homeowner, property manager, restoration team, and insurer.
3. Create the loss record. Photograph the source, standing water, water lines, every room, and damaged contents before moving items. Record what happened, who was contacted, and what action was taken. That creates a useful timeline for the homeowner, property manager, restoration team, and insurer.
4. Begin controlled drying. Extract water, identify wet materials, establish drying conditions, and monitor progress with instruments. Record what happened, who was contacted, and what action was taken. That creates a useful timeline for the homeowner, property manager, restoration team, and insurer.

What mistakes should you avoid?

• Entering contaminated water: Bare skin, ordinary shoes, and household vacuums do not provide suitable protection. The safest response is to limit exposure, document the condition, and obtain qualified help when the source or extent is uncertain.
• Throwing items away immediately: The insurer may need photographs, inventory, or inspection before disposal. The safest response is to limit exposure, document the condition, and obtain qualified help when the source or extent is uncertain.
• Using fans without assessment: Air movement can spread contamination or mould particles when the water source or affected materials are unsafe. The safest response is to limit exposure, document the condition, and obtain qualified help when the source or extent is uncertain.

How does professional documentation help?

Good restoration records connect observations to actions. Photos, moisture readings, equipment logs, material inventories, cleaning records, and written scope changes help everyone understand why work was required. They also reduce disputes caused by memory, rushed decisions, or hidden conditions discovered after demolition.

Firstline Restoration is licensed, insured for $5 million, and WSIB-covered. The team can document the loss, stabilize the property, carry out the approved restoration scope, and communicate factual project information to the adjuster without promising coverage or claim outcomes.

Frequently asked questions

Should I turn off electricity?

Only if you can reach the panel without entering water or an unsafe area. Otherwise stay out and call the utility, fire department, or a qualified professional.

Do I need to call insurance immediately?

Notify the insurer or broker as soon as reasonably possible, record the claim number, and ask what documentation and emergency-work process the policy requires.

Can I start drying before an adjuster arrives?

Reasonable emergency steps to prevent further damage are generally expected, but document first and keep the insurer informed.

Should I open windows?

Only when outdoor conditions and contamination make it appropriate. Professional drying often works best in a controlled area with dehumidification.

What should I photograph?

Capture the source, water depth, affected surfaces, room overviews, damaged contents, serial numbers, and any emergency actions.

When should occupants leave?

Leave or restrict the area for electrical, structural, sewage, severe odour, fire residue, or health concerns, following emergency or professional advice.

What should a written scope include?

A useful written scope identifies the affected locations, assumptions, work methods, protection, access, responsibility for permits or approvals, testing or verification, exclusions, and the process for unexpected conditions. It should also distinguish emergency work from permanent repair and state which selections or owner decisions are still open.

Ask for changes in writing before additional non-emergency work proceeds. A clear record protects the property owner and the contractor because it connects each cost and schedule effect to an observed condition or requested decision rather than relying on memory after the work is concealed.

What should a written scope include?

A useful written scope identifies the affected locations, assumptions, work methods, protection, access, responsibility for permits or approvals, testing or verification, exclusions, and the process for unexpected conditions. It should also distinguish emergency work from permanent repair and state which selections or owner decisions are still open.

Ask for changes in writing before additional non-emergency work proceeds. A clear record protects the property owner and the contractor because it connects each cost and schedule effect to an observed condition or requested decision rather than relying on memory after the work is concealed.