The first 24 hours after water damage are the most critical. Acting quickly and correctly can mean the difference between a manageable repair and a complete gut renovation. Here's exactly what to do.
Water damage moves fast. Within 24 to 48 hours, standing water and moisture-saturated materials create ideal conditions for mold growth — and once mold establishes itself, remediation costs increase dramatically. Whether you're dealing with a burst pipe, a sump pump failure, a roof leak, or storm flooding, the actions you take in the first few hours will significantly impact both the extent of the damage and the outcome of your insurance claim.
As IICRC-certified water damage restoration specialists serving London, Ontario and Southwestern Ontario, here is the step-by-step protocol we recommend to every homeowner.
Step 1: Ensure Safety First (0–30 Minutes)
Before entering a flooded area, assess the safety of the space. Turn off electricity to the affected area at the breaker panel if there is any possibility that electrical outlets, appliances, or wiring have been submerged. Never enter standing water if you are unsure whether electricity has been safely isolated.
If the water source is a sewage backup or toilet overflow, treat the water as Category 3 (black water) — it contains pathogens and requires professional handling with appropriate PPE. Do not attempt to clean this yourself.
If you smell gas, leave the building immediately and call your gas utility.
Step 2: Stop the Water Source (30–60 Minutes)
Identify and stop the source of water if possible. For burst pipes, locate your main water shutoff valve — typically near the water meter in the basement or utility room — and turn it off. For roof leaks, place buckets and use tarps if safe to do so. For sump pump failures during a storm, call a restoration company immediately as manual pumping will be required.
Step 3: Document Everything for Insurance (1–2 Hours)
Before removing any water or damaged materials, photograph and video everything. Document the water level, affected materials, damaged belongings, and the source of the water. This documentation is critical for your insurance claim and should be done before any cleanup begins.
Contact your home insurance provider as soon as possible. In Ontario, most standard home insurance policies cover sudden and accidental water damage (such as a burst pipe) but may not cover gradual seepage or overland flooding without specific riders. Understanding your coverage early helps you make informed decisions about restoration scope.
Step 4: Begin Water Extraction (2–6 Hours)
The faster standing water is removed, the less secondary damage occurs. For small amounts of water, wet/dry vacuums can be effective. For significant flooding, professional extraction equipment — truck-mounted extractors and submersible pumps — is required to remove water quickly enough to prevent structural saturation.
Professional restoration companies like Top to Bottom Seal use IICRC S500 Standard protocols for water damage restoration, which specifies extraction rates, drying targets, and documentation requirements that insurance companies recognize and accept.
Step 5: Remove Saturated Materials (6–12 Hours)
Porous materials that have been saturated with water for more than a few hours often cannot be effectively dried in place. This typically includes:
- Drywall — must be cut out to at least 12 inches above the water line to allow wall cavities to dry
- Carpet and underpad — almost always require removal and disposal
- Insulation — batt insulation holds moisture and cannot be effectively dried; it must be removed
- Baseboards and trim — typically removed to allow wall base to dry
Structural materials like wood framing, subfloor, and concrete can often be dried in place with professional drying equipment if addressed quickly enough.
Step 6: Deploy Drying Equipment (12–24 Hours)
Industrial air movers and dehumidifiers are the workhorses of water damage restoration. A professional restoration company will calculate the required number of air movers and dehumidifiers based on the affected square footage, material types, and ambient conditions — a process called psychrometric calculation.
Consumer-grade fans and dehumidifiers are insufficient for structural drying. They move air but do not create the pressure differential needed to extract moisture from within wall cavities, subfloors, and concrete. Using inadequate equipment is one of the most common reasons water damage claims result in mold growth weeks after the initial event.
What Happens If You Wait?
Mold can begin growing on wet organic materials within 24 to 48 hours under the right temperature and humidity conditions. London, Ontario's typical indoor temperatures are well within the range where mold thrives. Once mold is established, remediation requires additional steps, additional cost, and additional disruption to your home.
Secondary damage — warped hardwood floors, swollen door frames, delaminating cabinets, and deteriorating drywall — also progresses rapidly in the first 48 hours and can turn a manageable water damage claim into a major renovation.
Call Top to Bottom Seal for 24/7 Emergency Response
We provide 24/7 emergency water damage response across London and Southwestern Ontario. Our IICRC-certified technicians arrive with professional extraction and drying equipment, document the damage for your insurance claim, and begin the restoration process immediately.
Call 519-615-2900 any time — day or night — for emergency water damage assistance.